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A Customizable Middleware Framework for Accessing Mobile Sensors

1. Wireless Sensor Networks WSN xat xal a new tier of IT ecosystem global computing en vironment TO Va
2. GSM ap customization XAL XAL 4 20 and xat GSM 50 XAL XAL 6 CHAPTER 1 INTRODUCTION This work add
3. XAL O GSM SMS SMS MMS GSM TOWTOXOA XAL HAVE XML xar GSM and 6
4. and 20 xal ATO oe XAL query processing xal middleware GSM To 20 GSM TEOUN Web Services 30
5. brZ__ to which alaras will be sent equais the_2nd_Telephone return STELOZe else if 5ets_the_GSM_Telephone_nuabers_bri_up_to_0_br2__to_vhich_sleras_will_be_sent equals the_3xd_Telephone return STELOJ else if Seta_che_GSH_Telephone_munbers_dri__up_to_B to_which_slerss_will_be_sent equals the_4th Telephone return STELOJ stetecte else if Sets_the GSM_Telephone_muabers brl up to 8b which _alaras will_be_sent equnls the_Sth Telephone retum TELOS else if Sets_the_GSM_Telephone_nuabers__bri__up_to_0_br2__to_which_slaras_will_pe_sent equais the_6th Telephone return FTELDE else if 5ets_the_G5M_Telephone_nuabers_bri__up_to_0 br2__to_vhich_eleras_will_be_sent equals the_Tth Telephone return TELO7 else s Sets_the_GSM_Telephone_ruabers_br1__up_to_8_br2__to_which_slaras_will_be_sent equais the_Sth_Telephone return STELOD ecetettettetece else return _up_to_8_br2__to_vhich_sleras_vill_be_sent equals b JWS Figure 4 3 Autonomous Weather Station method with the parameters or variables specified and waits the response when there is one 4 2 A Framework Instance for a Mobile Observation Camera The Nokia Observation Camera will be showed in a different
6. Real time information can be requested with an SMS or listened through a voice synthesizer by placing a call to the unit The Weather Station is supported by the TCS OS Telecom Control Systems Operating System with system commands given via SMS or via Command Line for managing the station some of the commands and the corresponding SMS messages for this weather station are in Table 2 5 For instance we present three TCS OS commands of the Weather station e For enabling or disabling the generation of an alert SMS someone can use 4ALR lt status gt where lt status gt is ON or OFF for enable or disable In this case the body of the message is ALR and has the parameter lt status gt Some examples of use are ALRON ALR OFF space between ALR and value is optional or ALR requesting the status for alert messages e For setting telephone numbers to weather station there is TEL command Sets the GSM Telephone numbers up to 8 to which alarms will be sent There are three types of syntax for this command TEL returns all Telephone numbers up to 8 TEL lt xx gt returns the lt xx gt Telephone number with lt xx gt the Telephone position from 01 to 08 and TEL lt xx gt lt tttttttttttttt gt sets lt xx gt telephone number to lt ttttttttttttttt gt with lt tttttttttttttt gt the telephone number maximum 15 digits including a and is optional equal sign to improve readabilit
7. Silva Directed Diffusion forWireless Sensor Networking ACM IEEE Transactions on Networking 11 2002 2 16 D Ganesan TinyDiffusion Application Programmer s Interface API 0 1 http www isi edu scadds papers tinydiffusion v0 1 pdf 2001 TT 23 24 27 28 31 32 34 TinyDB A Declarative Database for Sensor Networks http telegraph cs berke ley edu tinydb Axelprod GSM Solutions GTM module network and dedicated PC based software management and different kinds of GSM modules and platforms http www axelprod ch index php rub home SPY EQUIPMENT Patriot unit GSM alarm monitoring system and GPS vehicle locating http www spy equipment co uk GSM_Alarm gsm_alarm html DPS Promatic GSM controls Telecom Systems a variety of GSM remote controls units http www dps promatic com default html Nokia UK Nokia Observation Camera http www nokia co uk nokia 0 5184 18287 00 html and http www nokia co uk nokia 0 8764 42939 00 html AUTOTECH Automation Technologies AUTOTECH Irida GSM Remote Control through GSM network http www autotech gr products php pcategoryid 23 amp pro ductid 15 amp set_lang en Ekopower Complete Datalogger System EKO21 http www ekopower nl eko21 htm GuardMagic GuardMagic SCT GuardMagic SC2x2 GuardMagic SC4x4 http www guardmagic com index html and http www guardmagic com engl 2e products e hard 01 htm Biene Electronics GSM
8. and iii end user a group of end user_description elements that includes different cases of frequently used interactions with the sensor as shown in the case of the mobile camera The first two elements include initialization and infoRequest tags specifying mes sages that will be sent For this case we use the tag message which contains a messageType tag The messageType contains SMS or MMS tag usually SMS for the requests with the body and the messageVar with choices or variables elements and optionally when it is needed a sender and a receiver In the messageVar there can be different choices or variables For each choice the choiceDescription the choiceValue and the choiceValueDescr ele ments can be specified For each variable the variableName and the variableDescription elements can be used An example is shown in Figure 1 of the Appendix Additionally there can be further information about the delivery message an alternative body of the message a url link with helping information etc In the case of end user the frequently used interactions are specified using the above tags In addition within the infoRequest elements there may be subtypes elements for the cases 81 de gt lt infoRequest gt lt message gt lt description gt Enables ON or Disables OFF the genaration of an Alert SMS lt desenption gt lt messageType gt lt SMS gt lt body gt ALRstatus lt body gt lt order gt 0 lt order g
9. defined by the framework Other examples are reflective frameworks presented in 41 42 43 To our knowledge none of the aforementioned particularly deals with the provision of WEB based access transparency over mobile sensors 26 CHAPTER 3 A MIDDLEWARE FRAMEWORK FOR ACCESSING MOBILE SENSORS 3 1 Introduction and System Architecture 3 2 Mobile Sensor Customizer 3 3 Server and WEB Page Proxies 3 4 Implementation Issues In this chapter we propose a middleware framework that unifies access to GSM enabled sensor devices in a global computing environment Typically communication with mobile sensors relies on their own protocols involving the exchange of SMS and MMS messages In the proposed framework we use XML based control descriptions that abstractly specify these protocols to generate proxies and corresponding WEB based HTML WAP and WEB services interfaces that realize them Thus we provide WEB based access transparency over different kinds of mobile sensors This chapter is structured as follows after the introduction and the detailed system architecture in Section 3 1 mobile sensor customizer and server and WEB page proxies will be described in Section 3 2 and 3 3 and finally Section 3 4 implementation issues of the middleware will be discussed 3 1 Introduction and System Architecture The World Wide Web has evolved into the major data structure for providing and access ing computer applications and other resources
10. description and will be discussed in details again in the next Chapter Finally for every mobile sensor that will be used a web server is customized This is the server proxy that uses the Web Service of the sensor In the parsing process every function that the sensor has was mapped in a method of the jws file which is in fact a Java file and those methods send the SMS messages to the sensor and wait the response when needed In the case of many commands in the same SMS there are two different types of implementation These implementations are different in the inner communication of the proxy server The Web Service caller WS Caller is the part of the proxy that communicates with the Web Service for the commands and gets the response When multiple commands are selected to be sent the number of commands that can be submitted from the WS Caller can be one by one or all of them The first type of implementation is the simple type that the customizer creates The WS Caller is connected to the GSM modem and the commands have to be submitted to the Web Service proxy only to be translated to SMS messages In that case we selected that the caller will send one command at the time and therefore there will be multiple calls of web services Then this program the WS Caller will collect the response and send the SMS message with all the requested commands As mentioned the first type of implementation is given by the customizer by default
11. gt lt xs all gt lt xs attribute name sensorName type xs string use required gt lt xs attribute name sensorPhone type xs string use required gt lt xs complexType gt lt xs element gt lt xs element name message gt lt xs element name delivery gt lt xs element name initialization gt lt xs element name end user_description gt lt xs element name subType gt lt xs element name infoRequest gt lt xs annotation gt lt xs documentation gt Requesting for information lt xs documentation gt lt xs annotation gt lt xs complexType gt lt xs all gt lt xs element ref message gt lt xs element ref delivery minOccurs 0 gt lt xs element name html_Info type xs string minOccurs 0 gt lt xs element ref subType minOccurs 0 gt lt xs all gt lt xs attribute name inOneMessage type xs boolean use optional gt lt xs attribute name isOptional type xs boolean use optional gt lt xs complexType gt lt xs element gt lt xs element name SMS gt lt xs element name MMS gt lt xs element name messageVar gt lt xs schema gt lth Figure 3 3 The XML schema for MSCDs perform these operations on the mobile sensor is the information that the customizer wants to acquire from the MSCD to generate a server proxy that actually realizes the operations which are exported by the server proxy in terms of a well defined WEB interface Specif
12. predistribution schemes and investigation of hardware support for public key cryptography are useful Protection against eavesdropping injections and modification of packets are also important and recent research shows that software only cryptography is indeed practical with today s sensor technology Further research is needed is matters as privacy robustness to communication denial of service attacks and resilience to node capture And finally im portant network secure services such as secure group management intrusion detection and secure data aggregation need improvement In our work again we combine web based interfaces and protocols with GSM GPRS When it cames to security and privacy the middleware can give the solutions as those issues have been studied in the context of the World wide web e g the https with additional en cryption authentication layer between HTTP and TCP In our work we don t treat security 12 issues but there are implementations and ideas integrated into the mobile sensors and their functions that can be activated The mobile sensors can distinguish among administrators and common users and assign privileges according to the access group they belong Some examples will be detailed later on when some mobile sensors instances are presented 2 2 Commercial Mobile Sensors There are many examples of commercial mobile sensors or GSM enabled sensors which are available and widely used today These sensors ar
13. subType gt lt body gt 3 lt body gt lt end user_description gt lt order gt 0 lt order gt lt end user_description gt lt alternBody gt temp lt alternBody gt lt message gt lt messageVar gt lt description gt Request the current temperature lt description gt lt SMS gt lt messageType gt lt messageType gt lt SMS gt lt message gt lt infoRequest gt Figure 3 4 Example of a MSCD specification for a mobile camera e Initialization information initialization tag in Figure 3 3 consisting of a set of alternative initialization protocols for the mobile sensor An initialization protocol specifies an ordered collection of request and response messages that must be exchanged between the proxy server and the sensor toward the sensor s initialization e Query delivery information infoRequest tag in Figure 3 3 comprising a set of al ternative query protocols for the mobile sensor Those query protocol prescribes an ordered collection of request and response messages that must be exchanged between the proxy server and the sensor to obtain the information provided by the sensor The query protocols represent possible user requests and use case in general when someone can chose what where and how information will be delivered It is also possible those protocols to involve the exchange of more that one commands or SMS messages to the sensor configuring the selected parameters The initialization and th
14. up to 8 to which alarms will be sent the 7th Telephone 306947937714 and back on top of the page Figure 4 2 Web based Interface for the Autonomous Weather Station after submitting one command to the sensor 4 1 1 Interface and Implementation Details The Web based interface that includes those functions is shown in Figure 4 1 where the func tions can be selected and the parameters or variables of the functions can be specified In this case those functions can be executed alone in one SMS that s why there option buttons in type of radio and the user can choose only one of the functions In other case check boxes will be useful for multiple selections This Web based interface is an HTML Form with a Submit and a Reset push buttons and any submission through this form executes a servlet that informs about our selection Figure 4 2 and calls the appropriate method of the Web service Those three functions in the case of the weather stations have led to three different meth ods in the proxy server that can be called The methods in the Java file jws Figure 4 3 b have as input the parameters or and variables for the function and combine the SMS mes sage body that have to be sent they use the GSM modem to send the SMS messages for the requests When a function is selected and submitted the servlet calls the appropriate Details for the XML file of the sensor description MCSD file can be found in the
15. 14 1 72 50 Comm Description 5 61 1 22 8 1 1 79 Requesting three commands to be sent in one SMS message Requesting five commands to be sent in one SMS message ii The complexity of the command varies as in the first set and in our measurement we have the average time of the different cases iii Same as in the second set of experiments we used both the two implementations we make use Web Services calls the Web Interface locally iv We used two MSCD files one with 10 commands and one with 50 commands described In the last set of experiments we compare our two implementations with the number of commands described in the MSCD file Table 5 6 shows the average times In this table four cases of experiments in our implementations are measured for the 10 commands description 64 file and the 50 commands description file The different approach in the types of implementa tion as described is mapped in the code of the WS Caller as cases of if statements In the first type of implementation it is one if else if case that stops when the suitable command is found then the web service call can be made In the second type there are many if cases checking each command in the set of commands that was requested In both implementa tions there are 10 or 50 clauses if cases for the 10 command or 50 command descriptions given When the requested command is found in the first type of implementation one cal
16. 9 Specifically the scenario executes as detailed below a The client selects Image and Temperature and the preferred resolution Figure 4 9 a b Then the client selects To E mail as as delivery mode and fills in the e mail address field Figure 4 9 b c After receiving the query the proxy server sends a control SMS message to the camera d Upon the reception of this message the camera sends image and temperature as mail attachment to the specified e mail address This last scenario combined with the first three scenarios can give the other use cases for the WAP interface Figure 4 10 about the first and last scenarios The above interfaces can be tested for the HTML based interface at http sensor proxy cs uoi gr index_ds htm and for the WAP based interface at http sensor proxy cs uoi gr index_ds wml The last created page with image and temperature information is stored in the Web Page Proxy at http apollonium cs uoi gr CAMERA camera html and another page may be http apollonium cs uoi gr CAMERA mms166 53 Pi 5 i gt er Web page proxy roxy server Client Web page proxy Proxy server Application Server Application Server Fill the html form Fill the html or WAP form CGI Get CGI Get Control SMS Popup Window Control SMS Messages Messages Popup Window Wait until information 7 Wait until MMS message is deli
17. Nr 8 Get LoG read a LOG string by SMS with GLG comma separated variables Request an SMS with weather data GTM INItialize Initialize all parameters to the INIT INI default value 710G LGV NOA PIN HPPP PWD PWR PRES RTC HSCA SMC FERN SRU STA STU SWA SWU Set the GSM TELephone numbers up to 8 to TEL which alarms will be sent Voice Call Functions VCF AVER Read Wind direction to align wind vane WDC 22 Figure 2 6 Installed GSM Autonomous Weather Stations GPRS modem and PPP software to send UDP packets to a WEB server special skills required to be able to use this option e Operating temperature range inside the box 0 50 degrees centigrade The station can be managed with the TCS OS Telecom Control Systems Operating Sys tem with system commands given via SMS or via Command Line when a terminal utility i e Hyperterminal is used or a PC with a serial cable to RS232 port for specific products is connected More details can be found in 32 and some of the commands for this weather station are in Table 2 5 In Table 2 6 details and characteristics of the above four sensors are combined Firstly this table provides information about the type and the appropriate network for those sensors Nokia Observation Camera is a GSM GPRS sensor Irida and BieneRemotel6GT are GSM data loggers and TCS Autonomous Weather Station supporting GPRS optionally Software and connection need for p
18. and please do not close this window click here to open PREVIOUS Image Page mms31 click here to open CURRENT Image Page click to go back to Selection Page close window Figure 4 7 Popup window 3 http apollonium cs uoi gr CAMERA mms32 Microsoft Internet Explorer File Edit View Favorites Tools Help Back O Psearch 77 Favorites Meda 8 S A U OD Address http apollonium cs uoi gr CAMERA mms32 v BE Links Web assistant Distributed Systems Lab Mobile Camera University of Ioannina Image of Fri Jun 11 2004 12 42 26 Temperature Temperature 27 C El MD Internet Figure 4 8 Results page 51 a The client selects Image and Temperature a resolution in this case the client changes the default resolution mode to high or compact and To E mail in the delivery op tions This textfield is activated and instead of set e mail the client has to white the necessary e mail address Figure 4 6 b After submitting the query a popup window appears and displays date and time asking the user to wait At the same time the server proxy sends the client request to the camera and waits until the results are delivered and c The camera receives the SMS message that encapsulates the client request and sends image and temperature data to the e mail address specified through an MMS message Pg Delivery Option Delivery 5
19. and some of the functions can be in more than one of those groups Apart from the name and the description of those functions there must be specified the variables or parameters of the commands for the functions A parameter can be for instance the on off or question mark usually when the status is requested and a variable can be an e mail address or a mobile phone number for delivering information and so on The commands are SMS messages with a generic message body and then the variables or and the parameters those are things specified for any function in the description The XML Schema that is used in our work is shown in Figure 3 3 some instances of the MCSD XML files for the Nokia Ob servation Camera and the Autonomous Weather Station are in Figure 3 4 and Figure 4 3 a In the later the instances of functions that require parameters or variables are detailed For any function there is also the information about the delivery the request can be a control SMS message but the response from the sensor can vary In the description of the function can included the type of the response e g SMS or MMS message the sender and receiver for those messages can be specified when it is needed and maybe a description of the body of those messages can be helpful in the case of unpacking the messages for receive the infor mation Moreover there are functions or commands that can be used together in the sense that one functi
20. average time of the middleware overhead in the different kinds of commands when we choose one command in one SMS message is given in Table 5 3 The average time in the cases of one two three and four commands in one SMS message to the sensor is given in 62 Table 5 5 Middleware overhead measurements in different case of requests in the Weather Station use case for the second type of our implementation 2nd set of Web Service calls Web Interface Web Interface Experiments locally Web page locally Internet connection second implementation Average time in sec Average time in sec Average time in sec Simple Command in one SMS message 1 06 Two Commands in Three Commands in Four Commands in Table 5 4 for the first implementation Moreover there is the distinction in two columns in order to measure the total time when the user interfaces were used These interfaces can be used though the Web page and the use of the servlet calling the Web Service or when the middleware was accessed without the interface Without the interface means through com mand prompt using a Java file that has the role of a client that calls the Web Service the WS Caller So there are two columns of the average time in the Table 5 3 and Table 5 4 for the cases of accessing through the user interface and simple Web Service call and also a third column with the measurements of the overhead when the use of the user interface is made through a different clie
21. be executed OFF SEC035 CALLBACK1 REPORT Store a keyword and the sequence SETMACROx SETMACRO1 IRIDA OUT1 ON MIN052 OUT2 OFF OUT3 XOR OUT4 OFF SEC035 CALLBACK1 REPORT Store programming values for SETMALARMx SETALARM1 6977763000 INI ON IN2 OFF AN1 gt 80 AN2 gt 55 AN2 lt 35 AN3 lt 10 OUT1 0N MIN052 OUT2 OFF CALLBACK1 REPORT Store in one of the memory locations SETSMSx SETSMS1 lt A BURGLARY IS the predefined SMS that the user CURRENTLY IN PROGRESS AT THE will receive in case of alarm SHOP IN 34 AEOLOY ST gt i Set and store the time and date SETDATE SETDATE in the GSM module Indicates if a notification SMS REPORT Indicates if a user defined SMS message system will receive commands and the of tasks to be executed alarms 1 to 4 PASS un z un will be sent to the phone number that has been programmed in memory SETCALL1 6970333330 OUT1 ON MINOS2 OUT2 OFF OUTS XOR Output activation and deactivation ON and OFF OUT4 OFF SEC060 REPORT Output activation for the time ON MINxxx and or indicated by parameter xxx ON SECxxx SETALARM1 6557763000 INI ON 000 to 999 minutes or seconds AN1 gt 80 AN3 lt 10 OUT1 ON MIN052 Then the output is deactivated SMS CALLBACK1 REPORT Output deactivation for the time OFF MINxxx and indicated by parameter xxx min or OFF SECxxx sec Then the output is activated Remote Control Commands Direct outputs management COMMAND or COM COMMAND OUTI 0N Request for a notification SMS STATU
22. case for mobile camera Finally it worths discussing a very common scenario where a client executes on a low end device with limited power processing and storage capabilities This is the case for the use of WAP based interfaces and if such kind of devices do not support the reception of MMS messages efficiently the option of building a WEB page that contains the results obtained by the sensor is the solution And those WAP based interfaces are generated by the customizer as well 3 4 Implementation Issues Speaking of our prototype implementation we can focus on three basic matters the XML Schema the proxy server and the GSM GPRS communication Firstly any MSCD file about a mobile sensor is base on the XML Schema mentioned above So the description of a mobile sensor has mandatory an optional fields of data Name 37 and phone number for this senor are optional but useful when they are known then any specific function command of the sensor must be detailed Some functions can be executed alone sending only the command messages for those and not with any other in the same SMS messages and some other can be sent together in the same SMS messages That s why it is specified for every function if this command would be sent in one SMS Those function commands are collected in groups of initiation requesting information protocols and end user description in the xml file in different tags as initialization and infoRequest
23. comm two comm tree comm five comm Number of commands in one SMS message Figure 5 3 Middleware Overhead Measurements for 50 Commands description file increases only with less than a second approximately for a Web Service call when the user interface is used with the web page and the servlet In addition the two implementations can lead to different overhead when multiple commandes are sent to the station Future work with distribution in the middleware would lead to the use of the first implementation because of the great overhead in the tested system architecture 5 3 Middleware Overhead in the Camera Use Case We performed experiments for determining the average response time for the framework instance of Section 4 2 for common query requests in various configurations The query experiments performed were the following i Requesting image and temperature with image resolution a default b high and c compact The request is issued through the WEB based interface and the results are delivered on a Web page Those are the first two protocols that were described in Section 4 2 2 with the only difference that in the second one with change of the resolution mode an e mail address was used for delivery In this case for the evaluation 67 Table 5 7 Response time and middleware overhead for experiment i sending message s in sec time average in sec Image with default resolution Image with high reso
24. connection There is no need for configuring duty cycle as there have no power issues Those are things that will be detailed later when some mobile sensors will be presented 2 1 3 Networking and Query Processing in Wireless Sensors Net works Moreover networking and query processing issues become deeply intertwined as queries are continuously processed within the network and this is the third aspect of the embedded Inter net vision Network and query processing must be co designed to allow data self organization for flexible but efficient in network storage access and processing In fact sensors networks have the potential to support applications ranging from habitat and structural monitoring to home and building automation to supply chain management Users are typically interested in continuous streams of information representing the evolving status of systems combined with periodic statistical reports about specific phenomena and even when some thresholds are used or alarm systems are triggered those alarm messages and the data reports Query processing systems provide high level interfaces that allow users to collect and process such continuous streams Speaking of stream data management the Aurora system 17 is an experimental data stream management system with a fully functional prototype including both a graphical de velopment environment and a runtime system In the future plants of the Aurora system 10 there is
25. e mail message To realize the first scenario the client has to fill up the options of the HTML forms given in Figure 4 5 and Figure 4 6 In particular the scenario proceeds as follows a The client selects Image and Temperature a resolution in this case default resolution mode and To web page in the delivery options Figure 4 5 Figure 4 6 b After submitting the query a popup window appears and displays date and time asking the user to wait At the same time the server proxy sends the client request to the camera and waits until the results web page is created Figure 4 7 c The camera receives the SMS message that encapsulates the client request and sends image and temperature data to the WEB page proxy through an MMS message d Upon the reception of the MMS the WEB page proxy uses a script to extract the data and creates the results page Figure 4 8 e After polling the WEB page proxy the server proxy gets the notification that the results page is ready Following the server updates the popup window with the final form that displays the link to the results page Figure 4 7 Similarly to realize the second scenario the client has to use the HTML forms as above Figure 4 5 and Figure 4 6 Specifically the scenario executes as detailed below 50 E Image History Microsoft Internet Explorer m Friday June 11 2004 12 40 28 Delivery Details please wait your request is being processed
26. efficiently operating and managing machinery and vehicles establish ing perimeter and building security protecting packages and containers monitoring supply chain management and helping deliver health care Sensors networks can extend to moni toring interactions among many objects within these domains ensuring asset management ubiquitous computing environments and emergency response Moreover those networks help feed information to autonomous distributed control devices They may help in applications used for road safety fire prevention temperature control precision agriculture systems and much more By using a middleware framework to improve the communication and proactive capabilities those networks can have Realizing important aspects of the embedded Internet vision includes the design and de velopment of applications hardware needed to collect physical data algorithms for gathering and analyzing this information and methods for robust and secure operation These issues are discussed in the remainder of this section 2 1 1 Applications Issues in Wireless Sensor Networks The first aspect of the embedded Internet vision as described before has to do with the applications of Wireless Sensor Networks that have been designed and developed There are several real world deployments of environmental monitoring such as habitat monitoring with sensors networks which deliver to ecologists data on localized environmental conditions ab
27. for networks users to both trust the incoming measurements and ensure the network s performance and longevity The health monitoring system relies on explicit and implicit signals Explicit signal can be the battery voltage of a sensor which provides information about the remaining capacity and implicit signal can be for instance out of range readings in the humidity that indicate a fault There are also many examples of environmental monitoring systems such as systems developed by Harvey Mudd College Harvey Mudd College Center for Environmental Stud ies with embedded networks that study issues in the relationship between human life and both natural and human built environments 3 and 4 with distributing remote sensors that would provide habitat monitoring via a wireless network grid to understand how local con ditions as temperature light intensity and noise affects lizard habitats Other examples are NASA s Volcano sensorweb project 5 and other autonomous observing sensorwebs 6 and 7 and UC Berkeley s habitat modeling at Great Duck Island Maine 8 and 9 On a much larger scale there are Environmental Observations and Forecasting Systems such as the EOFS project studying Oregon s Columbia River estuary CORIE system 10 and FloodNet intelligent sensor network which is included in EOFS of the University of Southampton s Envisense Center 11 a Center for Pervasive Computing in the Environment and is de sign
28. networks consisting of perhaps thousands of integrated devices with built in processing storage and sensor with RF transceiver energy storage and antenna is evolv ing quickly and a signature style of design is formulated Wireless sensor networks combine processing sensing and communications into tiny embedded devices Peer to peer commu nication protocols then combine the individual devices into an interconnected mesh network where data is seamlessly routed among all the nodes These networks require no external infrastructure and can scale to hundreds or even thousands of nodes Critical to the opera tion of any sensor network device is the ability to satisfy harsh always on power requirements and the periodic recharging is not possible for most cases Special purpose sensor nodes are purposely designed to satisfy flexibility in order to be as small and inexpensive as possi ble High bandwidth sensors contain the built in processing and communication capabilities needed to deal with complex sensor streams including video and voice processing Traditional network abstractions are generally not suitable for wireless sensors networks for instance unlike traditional operating systems operating systems for wireless sensors networks must tightly integrate wireless connectivity while gate way class and high bandwidth nodes use more traditional operating systems There are four main platform classes that have emerged recently in wireless sensor n
29. noss gt um z 3 nossos ES p to mobile phone orin this wap browser r z 2 8 8 2 2 w Ww a Filling delivery options b Setting up the delivery email address Figure 4 9 Using the WAP interface in the forth scenario In the third case to realize this scenario the client has to use the HTML forms and then a The client selects Temperature Only and To mobile phone in the delivery options This textfield is activated and instead of set phone number the client has to white the necessary phone number e g 306907937xxx Figure 4 6 b After submitting the query a popup window appears and displays date and time asking the user to wait At the same time the server proxy sends the client request to the camera and waits until the results are delivered c The camera receives the SMS message with the client request and sends image and temperature data to the e mail address specified through an MMS message 52 d Upon the reception of the MMS the WEB page proxy uses a script to extract the data and creates the results page Figure 4 8 and then the current temperature has to be delivered e After polling the WEB page proxy the server proxy gets the notification that the results page is ready Following the temperature from this page is extracted and delivered to the specified phone number Finally to realize the last scenario the client has to use the WAP interface given in Figure 4
30. on board or deactivation of the data loggers is an other specification characteristic depending on the logger and this was mentioned in the earlier descriptions of Irida and BieneRemotel6GT Finally those devices have specific alarming user management and power capabilities For instance BieneRemotel6GT does not support different user privileges or access code in its programming and use and the autonomous weather station supports a wide power supply range 12V to 35V DC or 12V to 24V AC an external solar power supply or a lead battery on board 2 3 Middleware Web Services and Messaging The work presented here generally relates to the integration of devices that communicate through SMS and MMS in a global computing environment Short Messaging Services or Short Message Sending SMS 33 is widely supported in mobile phones in most countries It allows users to compose short textual messages using the telephone handset and transmit them asynchronously Thus it is natural to bind together the pertinent telephony and com puting protocols so that computers can originate and perhaps receive such messages In that respect Short Messaging Services are offered by various cellular telephony providers through WEB interfaces In general XML has been used for sending SMS messages over HTTP 34 However 24 each vendor created its own implementation leading to interoperability problems To solve such problems the SMS Forum 35 develope
31. only half a second additional overhead time This amount of time can be increased in cases of slower connects when for instance we measured the time through an Internet connection Moreover between the first and the second implementation the cases of two tree and five commands in one SMS message the needed time doubles triples and is almost multiplied by five in the first implementation In the second one some addi tional milliseconds are added The amount of these milliseconds depends on the connection of the machine running the web service caller and the proxy server In our measurements this amount is 20 to 30 msec because they are running in the same computer The case of 50 commands description file follows the same rule doubles triples and multiples by five in average in the first type and has some additional milliseconds in the second type There is also additional time between 10 commands description and 50 commands description case and hence the time that is multiplied in the first type is increased Finally we can assume the differences in the overhead in the two types of implementation would become smaller as the number of commands described in the customization file increases and the commands became more complex In other words as the number of commands and the complexity of them increases the overhead for the second type of implementation will be similar with the overhead for the first one A faster connection will decrease the o
32. transfer data with the use of GPRS service Some of the specific instructions and requests with SMS messages to Irida are gathered in Table 2 3 Those commands must always be terminated with the sharp character and there are commands about programming remote control and output functions 2 2 3 GSM SMS Remote Control Module BieneRemotel6GM BieneRemotel6GM logger from Biene Electronics is shown in Figure 2 5 it s a GSM SMS remote control module that can be applicable in cases of remote monitoring in different kind of stations as transformer and wastewater remote control and alarm systems There are four different versions of this module BieneRemotel6GM S for digital signal monitoring and alarming BieneRemotel6GM 2A BieneRemotel6GM 4A both for analog and digital signal monitoring and BieneRemotel6GM 2SMT for temperature monitoring The user can re ceive an SMS message at occurrence of a certain event send a SMS message for managing of various equipment or requesting information about the target system status Independent monitoring up to 14 inputs and local control up to 6 outputs is possible The site for the 19 Figure 2 5 GSM SMS Remote Control Module BieneRemotel6GM GSM SMS Remote Control Module BieneRemotel6GM is 31 and the user manual demos and other information can be found there Someone can control be informed and configure this remote control module with short messages SMS It has a built in two ban
33. way We make use of a simple end user interface that can be described in the general MSCD file and has only some of the functions of the mobile sensor The MSCD file in the case of that camera is showed in Figure 3 4 But there is a part of this description that has some common and more useful commands e g for the camera the request for image and temperature are frequent This part of the description is simple and called simple end user description and includes three or four commands and the delivery options to phone number to e mail and maybe to a new web page There is also possible 46 to add additional options commands determining information type and mode image resolu tion enabling or disabling the additional delivery of temperature information when someone requests image and so on To take a look in some commands of Nokia Observation Camera the full list of commands is in Table 2 2 let s examine four of the commands that will be in the simple end user interface e image or 1 and image phone number e mail address or 1 phone number e mail address captures an image and send it the phone number requesting or to another phone number or to an e mail address if phone number e mail address is added in the command e g 1 6900123xxx sends image and temperature in an MMS message to the phone number 6900123xxx e 13 on off enables on or disables off sending current temperature with images e g when a
34. 7 to 1 Event notification enable 11118 Set active mode Event notification enable Set ON LINE 11119 Set ON LINE BieneRemote dial to first in phone book number Reset Output 1 Reset Output 1 1 Set Output 1 to 0 to 1 on terminal block Set Output 1100 to Ton terminal block an Reset Output 7 7 Set Output 1 to 0 Event notification disable Nnnn8 Set passive mode Enable Disable answer SMS Nnnn9 Enable disable switch active passive answer PARA A SMS for alarm mode only Default disable TCS AWS Telecom Control Systems for Autonomous Weather Station control electron ics has the following features e Built in Dual Band modem model Siemens TC35 e Wide power supply range 12VDC to 35VDC or 12VAC to 24VAC and a lead battery constant voltage charger on board e Solar panel power management on board e Speech synthesizer to speak weather data upon call e SMS handling to receive commands and send Weather status and alarms e Alarms wind speed and temperature with programmable thresholds Rainfall alarm available on versions with rain collector e Automatic message every 30 or 60 minutes in CSV format e Optional DTMF decoder to allow access only upon touch tone password 21 Table 2 5 TCS AWS GSM Autonomous Weather Station some of the commands in SMS messages SMS Command FALR HANS FARM CAP CLB FR CUP DeBuG send a copy of all incoming messages DBG to TELephone
35. A Customizable Middleware Framework for Accessing Mobile Sensors H METANTYXIAKH E EIAIKETIHN Mtron METAMTYXIAKOY ME 2006 you xat Randolph Carter ACKNOWLEDGMENTS I would like to thank my supervisor Ioannis Fudos Assistant Professor at the Computer Science Department of the University of Ioannina for his time support and patience during the elaboration of this thesis I would also like to thank Associate Professor Evaggelia Pi toura and Dr Apostolos Zarras for their help and valuable comments I am grateful for the opportunities the experiences and the knowledge that I gained from my collaboration with the members of the The Distributed Management of Data Laboratory Last but not least I would like to thank my friends and colleagues Xenia Antreas Toula Giorgos Nikoleta Kostas Marina and Irini for their help all these years and the girl with the strange name Zissis K Plits
36. Appendix 45 4 gt lt infoRequest gt lt message gt lt description gt Enables ON or Disables OFF the genaration of an Alert SMS lt description gt lt messageType gt lt SMS gt lt body gt ALRstatus lt body gt lt order gt 0 lt order gt lt alternBody gt ALR status lt alternBody gt lt messageVar gt lt choices gt lt choiceDescription gt changes status or gets current status for generation of an Alert SMS lt choiceDescription gt lt choiceName gt status lt choiceName gt lt choiceValue gt ON lt choiceValue gt lt choiceValueDescr gt enable lt choiceValueDescr gt lt choiceValue gt OFF lt choiceValue gt lt choiceValueDescr gt disable lt choiceValueDescr gt lt choiceValue gt lt choiceValue gt lt choiceValueDescr gt get status lt choiceValueDescr gt lt choices gt lt messageVar gt lt SMS gt lt messageType gt lt message gt lt infoRequest gt lt infoRequest gt lt message gt lt description gt NO Acknowledgment inhibits SMS acknowledgment lt description gt lt messageType gt lt SMS gt lt body gt NOA lt body gt lt alternBody gt lt order gt 0 lt order gt lt messageVar gt lt SMS gt lt messageType gt lt message gt lt infoRequest gt lt infoRequest gt lt message gt lt description gt Sets the GSM Telephone numbers up to 8 to which alarms will be sent get telephone lt description gt lt message
37. Define the master user 8_security code_user name_phone The e mail address is mandatory number_e mail address or master_security code_user name_phone number_e mail address Add a new use and give the right to 5 security code_user name_user s capture images and or phone number_on_on or use the audio connection add_security code_user name_user s phone number_on_on Remove a use 6_security code_user name The user can be removed phone number or based on either the user name remove_security code_user name or the phone number phone number Set the PIN code request on or off 22_PIN code_on off Someone can control and configure the camera with short messages SMS and the PC Suite for Nokia Observation Camera software is provided for more advanced functions This camera is approved for use on the GSM 900 1800 network and besides GSM network cover age a GPRS enabled mobile subscription with a SIM card and MMS service will be needed for its function As mentioned above an MMS and SMS enable mobile phone with color 16 display can be used to control the device and deliver the data In our work we make use of a GSM modem for control and an e mail address for receiving images Some of the specific instructions and requests with SMS messages to the camera are gathered in Table 2 2 and through that table more camera specifications can be discussed Please note that in the SMS Command column of Table 2 2 the underline character _ is used
38. Net works the vision of Embedded Internet becomes reality and different aspects of this vision can be focused Translating this vision into reality includes design and development of appli cations hardware and software systems algorithms for gathering and analyzing information and methods for robust and secure operations Moreover in a distributed and heterogeneous system of sensors middleware framework is needed among the operating system and the ap plications or devices on each side of the system Our goal in this thesis was to integrate a specific category of sensors GSM enabled sensors in a global computing environment built on top of the World Wide Web We proposed a customizable middleware framework that enables uniform access to mobile sensors According to the sensor protocols which involve the exchange of SMS and MMS mes sages we introduced a mobile sensor description to configure the middleware Starting from a general XML Schema for the description we demonstrated examples of mobile sensor cus tomization using a proposed Mobile Sensor Control Description MSCD XML file The customization process is based on creating the proxy servers and the interfaces of the mid dleware according to MSCD files We have detailed two sensors a GSM based Autonomous Weather Station and a Mobile Observation Camera We have performance experiments for determining the customization time of the framework from different MSCD files and the middlewar
39. S STATUS to supervisor phone number Per e 4 analog inputs for the connection of temperature sensors pressure sensors humid ity sensors etc or any other system that provides readings through analog outputs Alternatively the analog inputs may be used as additional digital inputs e 4 independent timers for each Relay output with time function 1sec 999min 18 e RS 485 amp RS 232 ports communication e And additionally the capability to expand the outputs and inputs by multiplying their number is provided The activation or deactivation of all individual devices that are connected can be remotely controlled by 1 commands through SMS that the device receives from a predefined telephone number supervisor or from any telephone number with a password 2 non answered toll free calls to the device utilizing the calling number identification service 3 keywords sent by the user in an SMS the user can program up to 8 different keywords There are also 8 different programmable combinations of alarm signals the device can provide information in regular time intervals about the inputs outputs status or information regarding the overall status of the device by an SMS or even by a non answered call More information can be found at the site for the Irida GSM 28 and the user manual can be downloaded there This logger is approved for use on the GSM 900 1800 network and besides GSM network coverage communicate
40. SMS Remote Control Module BieneRemotel6GM http www bieneelectronics com products bieneremotel6GM htm DPS Promatic GSM controls TCS AWS GSM Autonomous Weather Station http www dpspro com tcs_environ html GSM World the world wide web site of the GSM Association GSM SMS Overview a technical overview of SMS http www gsmworld com technology sms index shtml 2005 Nicholas Chase Tip Use XML to send SMS messages Reap the benefits of MMAP and SMAP developerWorks IBM s resource for developers http www 106 ibm com developerworks xml library x tipsms1 html 2004 The SMS Forum http www smsforum net 78 36 37 38 39 40 41 43 44 45 46 W3C Web Services Architecture Technical report W3C 2004 http www w3 org TR ws arch Guy Antony Halse and George Wells A bi directional SOAP SMS gateway service Proceedings of SATNAC 2002 2002 Vijay Kumar et al WAP Present and Future Pervasive Computing Vol 2 No 1 2003 Smith B C Procedural Reflection in Programming Languages PhD thesis MIT 1982 Available as MIT Techical Report 272 R Hayton A Herbert and D Donaldson Flexinet A Flexible Component Oriented Middleware System In Proceedings of the 8th ACM SIGOPS European Workshop ACM 1998 A Singhai A Sane and R Campell Reflective ORBs Supporting Robust Time Critical Distribution In Proceedings of ECOOP 97 Workshop on Ref
41. Those use cases have to do with accessing the mobile camera and the GSM autonomous weather station through WEB based and WAP based interfaces 40 CHAPTER 4 USE CASES 4 1 A Framework Instance for a GSM enabled Autonomous Weather Station 4 1 1 Interface and Implementation Details 4 2 A Framework Instance for a Mobile Observation Camera 4 2 1 Interface and Implementation Details 4 2 2 Protocols In this chapter the proposed middleware framework is used for two mobile sensors that were described earlier First the middleware framework instance for an Autonomous Weather Station is presented the resulting architecture is discussed along with the specific implemen tation issues of the servers and the interfaces that this middleware uses This GSM based Autonomous Weather Station was presented in Section 2 2 4 In Section 4 1 we outline the customization of the middleware framework to utilize its functions of sensing controlling and submitting data in general And in Section 2 2 1 a mobile camera was described In Section 4 2 we describe the resulting architecture the interaction protocols for this camera the Web based and WAP based interfaces 4 1 A Framework Instance for a GSM enabled Autonomous Weather Station In the case of the TCS AWS weather station from Telecom Control Systems the GSM based autonomous Weather station there are various parameters wind speed and direction tem 42 perature relative humidity precipitation
42. Type gt lt SMS gt lt body gt TELxx lt body gt lt order gt 0 lt order gt lt alternBody gt TEL lt alternBody gt lt messageVar gt lt SMS gt a XML import org spache axis client Call import org ap import org ap import Javax xml r public class sensor_tcs_avs public String Enables_bri_OM_br2_or_Dissbles_bri_OFF_br2__the_genaretion_of_en Alert Sits String changes status gets Current status bri for generation of an Alert SM3_brz it changes_status_or_gets_current_status_brl_for_generation_of_an Alert SMS _br2 equals enable return SALR ON else if changes_status_or_gets current status bri for generation of an Alert SNS br equals disable return ALR OFF else if changes_status_or_gets_current_status_bri_for_generation_of_an_Alert_SM3_br2 equals get_status return ALR 97 else return public String NO_Acknowledgaent__1mhib1t3_5NS5_acknowledguent return ANOA public String Sets_the_GSN_Telephone_rambers_ bri 8 br2_ which alarms vill be_sent String Sets_the 058 Telephone nuabers bri up to 8 br2_to which alaras vill be sent String ttettttettetet it Sets_the_CSH_Telephone_sumbers_ gt ell_mumbers return STE 1 Seto_the_0SM_Telephone_mumbera_brl_up_to_6_br2_to which aleras will be sent equals che_tst_Telephone return TELOL else if Sets_the_GSM_Telephone_muabers bri up
43. When the Web Service proxy is connected to the GMS modem and has the responsibility to send the SMS messages the WS Caller will sent all the requested commands and their variables We call this the second type of implementation and it is easy for the first type to transformed to the second type of implementation This fact leads to different choices in the final architecture of the mid dleware and the middleware framework can even be distributed as the components of the frameworks such as the proxy server or the GSM modem and the connection with that can be for instance in different servers in a local network In Chapter 5 we evaluated those different implementations for the cases of the com mands that can be submitted through the user interface the Web page with the Html form connected locally or through an Internet connection and with Web Service calls with the 39 WS Caller in command prompt mode Moreover we make use of a mobile phone for the GMS modem connected in the USB port of the PC for sending and receiving messages through the COM port that it was dedicated There is also an other server the Web page server that makes use of an e mail account and with unpacking the e mail messages in fact the MMS messages to e mail addresses with the information can generate the new Web page that includes the requested information In next chapter use cases will be examined before the evaluation of our prototype
44. a distributed stream processing system called Borealis Apart from dynamic revi sion of query results and dynamic query modification the ability of Distributed Optimization makes Borealis useful in application of wireless sensor technology 18 Moreover Stanford Data Stream Management 19 and 20 is another system with a first version of prototype even available for public use Researchers are beginning to formulate languages and enumerate the type of queries needed by users of sensor networks Distributed query processing is also needed as the data is stored and retrieved from nodes within the network Several in network query systems have been built for sensors networks Diffusion is the pioneering work developed by the Information Sciences Institute at the University of Southern California and presented in 21 as the directed diffusion paradigm for Wireless Sensor Networking and in 22 as the TinyDif fusion API implementation in TinyOS 16 There is no specific query language in Diffusion instead it allows application writers to choose a domain specific query language and focuses on query rooting mechanisms and flexible in network processing A family of routing algo rithms is provided and queries in the network are described by interest messages There is also TinyDB 23 which uses declarative queries that reflect their data processing needs specifying the types of data as well as the subset of nodes of interest along with simple
45. all the capacities needed for this kind of systems in order to be used stand alone and devices specifically designed for only one function needed in the system There are for example mobile sensors that have also communication capacities like mobile GSM thermometer and camera sensors and data loggers with communication capacities that can store and send the data from connected sensors through GSM or computer networks Of course the example of specifically designed devices parts of the monitoring system is the above figure Figure 2 1 There is a vast variety of mobile sensors used in any kind of monitoring systems form industrial use to commercial use and of course in house monitoring In addition to mea suring and monitoring environmental parameters they should also communicate the data collected and sometimes set alarms The sensors are designed in order to be connected and communicate their data and status informing about their measurements and their normal or not normal functionality There are sensors which need other communication devices like any kind of modems or data loggers and other sensors which include communication capacities and can be connected to many networks For this kind of design which integrate a monitoring and a communication system typical examples are some mobile cameras GTM module network and dedicated PC based software management from AxelProd 24 GSM alarm monitoring system and GPS vehicle locating system like th
46. asurements we included these different types of commands iii For this configuration of commands the two implementations have the same results as in both ones there is only one Web Service call iv We make use Web Services calls the Web Interface locally and the Web Interface through Internet connection v The MSCD file that were used described 25 commands For the second set of experiments Table 5 4 and Table 5 5 i The number of requested commands in one SMS message varies as follows Requesting a simple command to be sent in one SMS message with leads to four cases according to the commands complexity Requesting two commands to be sent in one SMS message which leads to 16 cases four cases for the first command combined with four for the second one Requesting three commands to be sent in one SMS message which leads to 64 Cases 60 Table 5 3 Middleware overhead measurements in the case of one command in one SMS message in the Weather Station use case 1st set of Web Service calls Web Interface Web Interface Experiments locally Web page locally Internet connection Average time in sec Average time in sec Average time in sec Command without parameter or variable Command with a variable Command with a parameter Commands with a parameter and a variable Requesting four commands to be sent in one SMS message which leads to 256 Cases Selecting only commands of a diffe
47. ate interfaces customized according to the MSCD of the sensor The interfaces include the forms of choices that are available in the case of initiation and requesting information as shown in Figure 3 5 for the initiation process of the weather station and in Figure 3 6 for the observation camera Following the proxy server receives the specified information and makes it available in client compatible formats The proxy server uses GSM to communicate with the mobile sensor and the mobile sensor responds by submitting appropriate SMS or MMS messages using GSM or GPRS respectively Distributed Systems Lab University of Ioannina Please fill in all necessary fields for the Commands some CAMERA commands Request image and temperature delivered in phone number e mail address the telephone number or e mail address Enable or disable sending current temperature with images changes status enable v Request the current temperature Change image resolution to compact normal or high the resolution mode compact Figure 3 6 Web based Interface for the Nokia Observation Camera some of the commands of the mobile camera that be selected The construction of this WEB page when it is requested is a responsibility of the WEB page proxy component which receives the MMS sent by the sensor in place of the client The result page has a unique id assigned incrementally by the framework The WEB page is creat
48. ation process gather the functions for the first part and uses the standard 47 Distributed Systems Lab Mobile Camera University of Ioannina Please fill in all necessary fields Information Type of information O Only Temperature SMS works only with mobile phone delivery option or Image and Temperature works with all delivery options Image Resolution default Delivery Please choose and fill in the text To E mail To mobile phone necessary if you want only Temperature Y To web page site Click to open the default image page Figure 4 4 Web based Interface for the Nokia Observation Camera in the End user sim ple case second part deactivated and has to activate the appropriate methods of delivery when a function is selected because some functions many not use all the given delivery methods The basic idea in creating the WAP based interface is the use of the first WAP card for choosing the function that the user want and then every function has its own different card for setting the appropriate parameters and or variables that this function needs Some ex amples are shown in Figures 4 9 about the Nokia Observation Camera in the case of simple end user interface the same that was described above for the Web based interface The behavior of proxy servers is rather typical as it materializes the alternative initializa tion and query protocols specified in the MSCDs that w
49. client preferences the sensor acquired information may be delivered to an e mail address to a mobile phone or to a WEB page because in the case of a Web page when we know the format of the delivered information we can automatically generate this page In a sense the proposed middleware framework is reflective 46 since it self customizes its interfaces with respect to constraints imposed by each particular sensor that participates in the global computing environment An overview of our architecture is illustrated in Figure 3 2 Figure 3 2 intoduces the concept of middleware customization with a mobile sensor description shown in the right side The global computing environment we consider comprises clients using different WEB enabled devices such as personal computers laptops and PDAs to access available resources Mobile sensors communicating through GSM and GPRS are a particular kind of such re sources Our framework consists of three main components namely a mobile sensor cus tomizer and different kinds of server and WEB page proxies The server and the WEB page proxies are sensor specific and establish communication between the clients and the sensors On the other hand the mobile sensor customizer serves for generating the aforementioned sensor specific components given the specification of Mobile Sensor Control Descriptions MSCDs The rest of this chapter further discusses the main responsibilities of the compo nents that consti
50. d 900 1800 or tri band 900 1800 1900 Telit GM862 GSM Modem programmable via SMS embedded software and on board power supply voltage regulator in a small size package Some of the specific controls commands for the standard version BieneRemotel6GM S are shown in Table 2 4 The user can get the current status set or reset the outputs and the notification set the logger ON LINE and enable or disable switch active passive answer SMS 2 2 4 TCS AWS GSM Autonomous Weather Station In the case of the TCS AWS weather stations from Telecom Control Systems we have a reliable GSM based autonomous Weather stations and there are available various versions to measure parameters like wind speed and direction temperature relative humidity pre cipitation Figure 2 6 illustrates installed weather stations Real time data can be requested with an SMS or listened through a voice synthesizer placing a call to the unit data can be logged on a 4 Mbit logger or can be sent directly to a server via GPRS UDP packets 20 Table 2 4 An example of GSM SMS Remote Control Module BieneRemotel6 standard version control commands SMS Command Get input state output state charge status and Get Status jjjj reference source for ADC for instance I 111111111111 O 10000000 CH 100 Set Output 1 jjjj1 Set Output 1 to 1 to 0 on terminal block Set AA 2 33152 Set Output 2 to 1 to 0 on terminal block RA Output 7 Set Output
51. d two relating standards Short Messaging Ap plication Part SMAP an XML format for the messages themselves and Mobile Messaging Access Protocol MMAP a SOAP based protocol for sending those messages Simple Ob ject Access Protocol SOAP is a simple XML protocol for exchanging structured information over the Internet and is amongst the core standards that formulate the overall Web Services architecture 36 SOAP lies on top of a variety of transport protocols such as HTTP and SMTP The aforementioned standards constitute a foundation for communicating with mobile sensors using SOAP An approach that actually realizes such communication capabilities is detailed in 37 In particular the authors propose a bi directional SOAP SMS gateway ser vice This approach bears some similarity with our framework The gateway service gets SOAP requests from the client application makes use of a database and a GSM modem to access mobile sensors and sends SOAP responses The service described in this context runs as a common gateway interface CGI script on an Apache WEB server Implementation wise there are several common points between this approach and our framework However a ma jor difference is that our approach unifies access to different types of mobile sensors through WEB based interfaces generated automatically The implementations of these interfaces translate client requests to sensor specific sequences of SMS control messages Our system furthe
52. e Patriot unit from Spy Equipment Law Enforcement Systems 25 the TCS CAM developed by DPS Promatic a reliable GSM digital camera for stand alone applications which is used to take a pictures and send it over a GSM network 26 and Nokia Observation Camera Figure 2 2 used to take pictures and more 27 In addition Data loggers have digital and analog inputs for the connection of devices with analog outputs temperature sensors pressure sensors etc or digital outputs and signals from alarms There are also data loggers with independents outputs of activation and deactivation of devices that are connected and their communication capabilities might include commu 14 nication ports RS 485 or RS 232 ports are common or and GSM GPRS connection with included modems These loggers have of course different methods of control in a remote manner used for activation and deactivation of the individual devices that are connected to them These are some examples of the latter data loggers AUTOTECH Irida GSM which offer remote control through GSM network 28 Ekopower Complete Data Logger System EKO21 29 and GuardMagic SCT GuardMagic SC2x2 GuardMagic SC4x4 devices 30 wy Figure 2 2 Nokia Observation Camera sending MMS or e mail messages with image and temperature data Continuing some examples of mobile sensors their specifications and capabilities will be presented sensors that will be use in our middleware f
53. e part of monitoring and alarm systems and they are useful in environmental measuring and logging It is also common for the mobile sensors to have the communicational capacities in order to transmit data to different kind of networks and even to send alarm signals to the appropriate users GSM Modem XR5 Logger Prevage Temperature View real time and logged data from the comfort of your office Figure 2 1 GSM Remote Monitoring and Alarm System XR5 Data Logger for pressure tem perature level flow weather power vibration etc with the use of GSM Modem Wavecom WCOD2 GSM modem In Figure 2 1 different parts of a remote monitoring system are shown There are some sensors measuring environmental parameters like pressure temperature level flow weather power vibration etc from the power system shown on the left Those measurements are collected by a data logger and through a GSM modem are communicated to the administra 13 tor These systems should be programmed remotely using any Windows terminal emulator and send data to mobile phone using SMS text messages This is a typical example of the implementation of a monitoring system combining sensors loggers modems and terminals using their functionality and properties The power storage bandwidth communication or other capacities of the devices used can lead to a variety of monitoring systems implementation There are devices which in clude some or even
54. e query protocols customize the content type provided by the mo bile sensor and several other content dependent quality attributes that specify characteristics of the data type that will be delivered infoRequest tag in Figure 3 3 For instance the content types may be image video or text and the attributes may specify characteristics such 34 Distributed Systems Lab University of Ioannina Please fill in all necessary fields for the Commands r Initiation commands Selects access mode for Voice call function more info Chooses Function available upon voice call Free Access X Enables ON or Disables OFF the genaration of an Alert SMS more info changes status or gets current status for generation of an Alert SMS enable Stores and reads text for programmable Alarm Messages more info changes alarm message temperature alarm message y sets alarm message or for show Alarm message Auto Reset gsm Modem daily at 3 00 am more info changes status or gets current status enable C Change Admin Password more info ADMIN Password Figure 3 5 Web based Interface for the Autonomous Weather Station part of the initiation commands as image resolution video compression or image format The WEB interfaces generated by the customizer facilitate the selection between alternative initialization and query protocols as they allow the clients to set their preferences rega
55. e telephone number maximum 15 digits including a the selected Telephone number lt vardescription gt lt vanable gt lt messagavar gt lt SMS gt lt messageType gt lt message gt lt html_Info gt http www dpspro com tcs_commands tcs35_tel html lt html_Info gt lt infoRequest gt Figure 1 Part of the GSM Autonomous Weather Station description file that the request for information has optional characteristics that can be chosen for instance when we can select the resolution of an image and then request for the image from the camera Figure 1 shows a part of the MCSD file in the cases of the GSM Weather Station that was presented in Section 2 2 4 82 AUTHOR S PUBLICATIONS Z K Plitsis I Fudos E Pitoura and A Zarras On Accessing GSM enabled Mobile Sensors 2nd International Conference on Intelligent Sensors Sensor Networks and Information Processing 2005 ISSNIP 2005 Melbourne Australia December 2005 xa 2005 4 SHORT CV Zissis Plitsis MSc Stud
56. e time overhead in the 73 cases of the weather station and the mobile camera In the case of the weather station we evaluated different cases of requests in two implementations and for the mobile camera we measured the whole process of requesting and delivering data image and temperature ac cording to the interaction protocols that were detailed Future work may include different kinds of sensors for example sensors that use different communication protocols like WiFi based on the IEEE 802 11 and sensors that send streams of data The middleware can be made more distributed as different parts of the architecture can be in a local network There are many choices regarding the implementation and the position of the proxy servers the web interfaces This fact leads to a variety of solutions and latencies and this is the reason that different implementation and distribution can be an interesting aspect to be discussed materialized and evaluated in future work Finally we can evaluate the performance of the middleware in more complex scenarios where multiple users simultaneously request data from sensors 74 BIBLIOGRAPHY 1 2 10 11 The ObjectWeb consortium What is Middleware http middleware objectweb org SPECIAL ISSUE Wireless sensor networks Communications of ACM Vol 47 2004 p 30 57 Harvey Mudd College Center for Environmental Studies http www environcenter hmc edu J Hicks Lizardne
57. ed to provide more accurate flood warnings Future projects include NASA s sensorwebs in New Mexico deserts and in Antarctica and sensors networks on both Mars and Jupiter s moon Europa as mentioned in 12 about sensrowebs In addition researchers working on di verse projects have developed novel applications for sensor networks technology and projects Projects like GlacsWeb about sub glacial bed deformation 12 sensor networks for detecting vehicles transporting radioactive isotopes 13 and detecting location of a sniper in a complex urban terrain 14 and The Flock in the core of the computer engineering curriculum in which mote sensors sing 15 are examples of this diversity of applications Our work pro vides a complementary middleware solution for integrating different GSM enabled sensors in a computing environment with heterogeneous components and distribution The long term outdoor deployment of such environmental monitoring systems with Wire less Sensors Networks stress reliability low power operation network protocols data quality and new experimental processes The future habitat monitoring networks and wireless sen sor networks applications in general would be enhanced with robust localization calibration clock synchronization and data processing 2 1 2 Hardware Technology of Wireless Sensors Networks The second aspect is the hardware technology The underlying hardware technology for wire less sensors
58. ed upon the arrival of the email message that contains the MMS built by the sensor as in the instance that Figure 3 7 b shows Synchronizing the client and the WEB page proxy is an issue tackled by the proxy server During the processing of a client request the proxy 36 server waits for the creation of the result page at the WEB page proxy and then notifies the client The proxy server uses polling to realize the previous task While the client request is being processed a popup window is open at the client s browser highlighting the progress of the client s request as in Figure 3 7 a for the case of the observation camera Ej http apollonium cs uoi gr CAMERA mms32 Microsoft Internet Explorer Image History Microsoft Internet Explorer File Edit View Favorites Tools Help Friday June 11 2004 12 40 28 E AM A seach sy Favorites Meda D03 Address a http fapollonium cs uoi gr CAMERA mms32 v FE co Links web assistant Delivery Details Distributed Systems Lab Mobile Camera University of Ioannina please wait your request is being processed Image of Fri Jun 11 2004 12 42 26 and please do not close this window click here to open PREVIOUS Image Page mms31 click here to open CURRENT Image Page mms32 click to go back to Selection Page Temperature Temperature 27 C amp Internet a Popup window b Results page Figure 3 7 End user
59. ent Zissis K Plitsis received his Diploma in Electrical and Computer Engineering from the Polytechnic School of Aristotle University of Thessaloniki Greece in 2003 He has been a MSc degree student in the Department of Computer Science in the University of Ioannina since November 2003 He has worked in ITI Informatics and Telematics Institute in Thes saloniki during his thesis on Software Agent Techniques in Learning Environments under the supervision of Prof Michael G Strintzis and Prof Demetrios Sampson Zissis has been a student member of the IEEE Aristotle University IEEE Student Branch and he is a member of the Technical Chamber of Greece since 2004 Recently Zissis has joined the army and will be serving in the Hellenic Navy until August 2007 E Mail zplitsis es uoi gr or zplitsis yahoo com
60. ere used for generating the servers In particular the proxy server collects requests for information issued by clients and trans lates them into sequences of sensor specific requests such as SMS messages Following the proxy server receives the specified information and makes it available in client compatible formats At this point it worths discussing a very common scenario the client has the option of building a WEB page that contains the results obtained by the sensor The construction of this WEB page is a responsibility of the WEB page proxy component which receives the 48 Distributed Systems Lab Mobile Camera University of Ioannina Please fill in all necessary fields Information Type of information Only Temperature SMS works only with mobile phone delivery option or O Image and Temperature works with all delivery options Image Resolution default Figure 4 5 Filling delivery information Delivery Please choose and fill in the text To E mail set e mail To mobile phone 58 phone number necessary if you want only Temperature To web page site Click to open the default image page Figure 4 6 Setting up delivery destination MMS sent by the sensor in place of the client The result page has a unique id assigned incrementally by the framework The WEB page is created upon the arrival of the email message that contains the MMS built by the sensor Synchronizing the client a
61. et works as Table 2 1 shows which is mentioned in 2 Initial deployment experience has show that sensor network systems require a hierarchy of nodes starting at low level sensors and continuing up through high level data aggregation analysis and storage nodes This tiered architecture is common in virtually all sensors networks it starts with the head or gateway nodes which provide an interface into many existing types of networks and then includes acoustic video or chemical sensors as examples of high bandwidth nodes requiring more computational resources and communication sensors placed on windows and doors for instruction detection as examples of generic sensing devices and finally mini motes like low cost security tags attached and tiny for tracking mobile assets as well as personnel Moreover the data produced by the sensor network gain scientific validity through a verifica tion process and collaboration in other words there is the need for frequent calibration and the data have to be compared to independent calibrated instruments A verification network is the application component responsible for collecting these independent readings and has often fewer but more established sensing devices of the upper rows of Table 2 1 It needs to provide the data quickly so the function of a sensor patch can be adjusted faulty sensors Table 2 1 Sensors hierarchy in wireless sensor networks each platform class handles different types o
62. f the Middleware Framework and I the Mobile Sensors through the User Interface or not APPLICATIONS lt User Interfaces WEB WAP air men vn rts rra e g SOAP messages i Application Interface API Fi Web Services or simple CGI etc Middleware Framework lee Sensors Sensors Sensing devices communicating data Figure 3 1 Architecture Layers Hence the initialization and the gathering of information provided by mobile sensors varies depending on the type of the sensor In principle a global computing environment such as the ones we examine 45 shall comprise many different types of sensors Conse quently the aim of this work is to propose a middleware framework that enables a uniform WEB based access to mobile sensors To this end each mobile sensor is accompanied by a description called Mobile Sensor Control Description MSCD that serves as input to the proposed framework and will be discussed later Based on the MSCD we generate sensor specific proxy servers and corresponding WEB interfaces The generated proxy servers realize the necessary procedures for the sensor initialization and the gathering of information accord 30 ing to several sensor specific parameters that can be customized by the clients through the WEB interfaces The clients may use different devices such as personal computers laptops or PDAs with Internet access Depending on the
63. f sensing Class Level of Nodes A few gateway nodes Web interfaces databases Second Dozens of high Cameras microphones bandwidth sensors Third Hundreds of generic Door window sensor nodes motion sensors Forth Thousands of special Asset tags purpose sensors can be eliminated and help the maintenance of the network In our middleware framework the sensors that we use are of the class of high bandwidth sensors and gateway nodes Once again the operating system running on a particular platform must be matched to the platform s underlying hardware capabilities For special purposes and generic sensor class devices a special operating system called TinyOS developed at the University of California Berkeley 16 is designed to run on platforms with limited CPU power and memory space Unlike many embedded operating systems it provides tight integration between wireless con nectivity and networking functions However as platform capabilities improve for example in the case of the Stargate platform a type of gateway node more advanced operating sys tem support is required to meet the demands of more complex applications Multiprocessing preemptive tasks switching and even virtual memory support become desirable when man aging multiple system functions The Stargate node runs an embedded version of Linux operating system and in addition to provide a range of system capabilities Linux provides a suite of device drive
64. facilities are needed for storage and correlation than the available in nowadays 2 1 4 Security and Privacy in Wireless Sensors Networks Finally effective security and meaningful privacy is an other important aspect of the sensors networks the technical aspects of these issues must be addressed from the start of any sys tem s design process in the context and the applications Sensors networks are susceptible to a variety of attacks including node capture physical tampering and denial of service while prompting a range of fundamental research challenges Sensor network security should be properly addressed from the start because there are unique new challenges in the network of limited in energy computational and communica tional capabilities sensor devices They are also deployed in accessible areas presenting the added risk of physical attack and interact closely with their physical environment and with people posing new security problems It is crucial that security pervade every aspect of system design and be integrated into the system and every component of it In this case of wireless sensor networks for instance the cryptographic key establishment of the network is very different than the well studied same problem in previous networks that proposed a variety of protocols and solutions We need a secure and efficient key distribution mecha nism allowing simple key establishment for large scale sensor networks Better random key
65. for spaces and that those commands can be sent in one SMS separated by a comma There are commands about get ting information image or and temperature setting the camera parameters the automatic imaging and the connection and finally user and security commands 2 2 2 IRIDA GSM Figure 2 4 IRIDA GSM from Autotech Irida GSM logger from Autotech is shown in Figure 2 4 This logger allows wireless re mote control through cell phone and can be useful in remote paging telemetry and alarm applications It has been programmed on a user friendly philosophy by SMS messages or by a PC through a serial port IRIDA GSM has e 4 independent outputs for activation or deactivation with or without time delay of devices that have been connected to these outputs either at home or in the factory Examples of such devices are various household electric or electronic devices 17 e 4 digital inputs for the connection of devices with N C outputs or signals coming from alarms or directly from gas motion fire detectors etc Table 2 3 Some of Irida GSM instructions SMS Command Syntax Examples PASS 11114 Store the Supervisor phone SUPERVISOR SUPERVISION 6970333330 number in memory PASS 1111 the 1st time Replace the current code default 1111 CHPASS CHPASS 1111 1234 with a new one Store the phone number from which the SETCALLx SETCALL1 6970333330 OUT ON MIN052 OUT2 OFF OUT3 XOR OUT4 sequence of commands to
66. ically the mobile sensor customizer supports the generation of two different types of server prox ies 1 servlets providing HTML or WAP based interfaces and 2 Web Services providing WSDL compliant interfaces Figure 3 3 gives the XML schema for the MSCDs used by the mobile sensor customizer In detail the MSCD of a mobile sensor consists of the following elements 33 lt sensor xmins xsi http www w3 org 2001 XMLSchema instance xsi noNamespaceSchemaLocation sensor xsd sensorPhone sensorName Nokia Observation Camera gt lt info gt lt init gt lt end user gt lt initialization gt lt end user_description gt lt message gt lt message gt lt description gt Set Camera Name lt description gt lt description gt Image and Temperature lt description gt lt messageType gt lt messageType gt lt SMS gt lt SMS gt lt body gt 25 camera_name lt body gt lt body gt 1 emailOrPhoneNumber lt body gt lt order gt 0 lt order gt lt order gt 0 lt order gt lt messageVar gt lt messageVar gt lt variable gt lt variable gt lt variableName gt Camera Name lt variableName gt lt variableName gt emailOrPhoneNumber lt variableName gt lt varDescription gt the name of the camera lt varDescription gt lt varDescription gt e mail phone number or web page lt varDescription gt lt variable gt lt variable gt lt messageVar gt lt messageVar gt lt SMS gt lt SMS gt l
67. ime and middleware overhead for experiment ii Response time and middleware overhead for experiment iii 16 18 21 22 24 57 60 61 62 63 64 68 69 69 ABSTRACT Plitsis Zissis ZP MSc Computer Science Department University of Ioannina Greece Oc tober 2006 A Customizable Middleware Framework for Accessing Mobile Sensors Thesis Supervisor Ioannis Fudos Sensing monitoring and controlling devices have been used in industry for many years The evolution of microcomputers and the increasing needs for sensing and controlling have led to new sensing devices being smaller cheaper capable of new applications and con nected in wireless networks This new area of research and development is known as sensor networks or Wireless Sensor Networks WSN WSN consist of hundreds of self contained battery powered sensing devices that measure and communicate wirelessly environmental data They are embedded in the environment can act proactively and can be presented as a new tier in the Information Technology ecosystem A global computing environment built on top of the Word Wide Web can integrate sensors and provide the appropriate applications and interfaces to utilize different kinds of sensors To handle such distributed heterogeneous and oblique systems we shall adopt the approach of a Middleware Framework as the soft ware layer between the operating system and the application
68. iny low power devices spread over large physical spaces collaboratively monitoring the environment guide vehicles and predict potential faults in buildings bridges roads and rails Communications of ACM June 2004 vol 47 no 6 2 Wireless Sensor Networks are new important tier in the IT ecosystem and a emerging domain of active research and development involving issues in hardware and system design networking distributed algorithms programming models data management security and social factors Through the use of Wireless Sensor Networks the vision of an Embedded In ternet becomes reality in this vision networks of interconnected computing devices deeply embedded into the physical environment transform whole fields of science engineering and manufacturing by providing detailed instrumentation of many points over large spaces both natural and artificial As an example the Global System for Mobile Communications GSM the most popular standard for mobile phones in the world can be used in connecting obser vation cameras weather stations and other kinds of sensors to transmit images temperature information and other data By doing so we implemented an embedded wireless sensor net work over the common network of cellural phones The pervasive instrumentation that wireless sensors networks provide will be of great value in many applications including understanding ecosystems dynamics setting land use policy protecting property
69. ional SMS request message is required in the query protocol so as to appropriately set up the corresponding quality attribute of the mobile camera The need for this additional message almost doubles the overall response time For the second experiment the results are illustrated in Table 5 8 In this case a results page is created with image and temperature info Subsequently the temperature info is extracted from the page and an SMS message is 68 Table 5 8 Response time and middleware overhead for experiment ii Type of experiment Average preparation time for Overall response message sending in sec time average in sec IA m m the mobile phone 14 2 107 6 sent to the user s mobile phone with the temperature info only The average time is 107 6 sec with 15 sec standard deviation Here it is important to mention a detail in the middleware that affects the overhead and the above deviation this detail has to do with a log file that is accessed and update when a request is submitted This is an add on feature in the mid dleware and the size of this file can vary as it is updated or deleted manually The deviation can be effected not only by the load on the server but also from keeping this log file updated Table 5 9 Response time and middleware overhead for experiment iii WAP access in sec Getting image and temperature Getting temperature at a mobile Getting temperature at the same mobile phone in the Wap Bro
70. is CONTENTS Contents List of Figures List of Tables 1 Introduction 2 Wireless Sensors and Sensor Networks An Overview 2 1 Wireless Sensor Networks dio 22 ada ka Boe Bee 2 1 1 Applications Issues in Wireless Sensor Networks 2 1 2 Hardware Technology of Wireless Sensors Networks 2 1 3 Networking and Query Processing in Wireless Sensors Networks 2 1 4 Security and Privacy in Wireless Sensors Networks 2 2 Commercial Mobile Sensors 2 zur 2 a 2 Pe en A kos 2 2 1 Nokia Observation Camera un rat A A a a a 22 2 ARIDA GSM aa A Ea ede Ou Bt ide 2 2 3 GSM SMS Remote Control Module BieneRemotel6GM 2 2 4 TCS AWS GSM Autonomous Weather Station 2 3 Middleware Web Services and Messaging 3 A Middleware Framework for Accessing Mobile Sensors 3 1 Introduction and System Architecture Au sanken 3 2 Mobile Sensor Customizer N 2 OE SS ONS ROS BO As 3 3 Server and WEB Page Proxies 2 254 8 2 Wa Ba a et 3 4 Implementation Issues rm ea ah 4 Use Cases 4 1 A Framework Instance for a GSM enabled Autonomous Weather Station iii ono Aa A 10 12 13 16 17 19 20 24 28 28 32 36 37 42 42 4 1 1 Interface and Implementation Details 4 2 A Framework Instance for a Mobile Observation Camera 4 2 1 Interface and Implementation Details 0 O he Sh 5 Performance Evaluation 5 1 Customization Overhead 2 2 om on nn 5 2 Middleware O
71. l is made and the execution continues In the second implementation where a set of commands is requested we have to pass through all of them and call the web service when we have a match That s why in the first type of implementation we have many calls with preparation time that varies for call to call finding one case and in the second type we have one call with preparation time that is about the same checking all the cases Middleware Overhead Measurements 10 Command Description web service call 1st impl E web service call 2nd impl Time in sec 7 simple comm two comm tree comm five comm Number of commands in one SMS message Figure 5 2 Middleware Overhead Measurements for 10 Commands description file Table 5 6 shows how parameters like the type of implementation the number of commands in the description file the number of requested commands in the same SMS message and the use of Web Service call or the user interface affects the measured middleware overhead In particular the Web interfaces costs half a second for every web service call approximately In the case of simple commands it is the same for the implementations and in the other cases 65 the first type of implementation has two tree and five web service calls which add 1 1 5 and 2 5 seconds in average to the user interface overhead In the second implementation with only one web service call there is
72. lective Real Time Object Oriented Programming and Systems ECOOP 1997 T Ledoux Implementing proxy objects in reflective orbs In Proccedings of ECOOP 97 Workshop on CORBA Implementation Use and Evaluation ECOOP 1997 G S Blair G Goulson and M Papathomas An Architecture for Next Generation Middleware In Proceedings of MIDDLEWARE 98 IFIP 1998 191 203 Cameron Laird SMS Case study of a Web services deployment Instant gratification programming results developerWorks IBM s resource for developers http www 106 ibm com developerworks webservices library ws sms html 2001 Evaggelia Pitoura et al DBGlobe a Service Oriented P2P System for Global Com puting SIGMOD Record 32 2003 77 82 J Malenfant M Jacques and F N Demers A Tutorial on Behavioral Reflection and its Implementation In Proceedings of REFLECTION 96 ECOOP 1996 79 APPENDIX Description of the basic tags in the MSCD XML file The basic elements of an XML file that describes a mobile sensor are i init a group of initialization elements that describes different cases of initializa tion processes for the mobile sensor for instance when we select a name for the sensor device or we set the phone number of the administration user ii info a group of infoRequest elements that describes different cases of requesting information from the sensor for instance when we request weather measurements from the weather station
73. lution and temperature at web page 13 3 1st SMS 22 7 2nd SMS two SMS messages Image with compact resolution and temperature at web page 14 1st SMS 25 4 2nd SMS two SMS messages an e mail address is also used but then the message is unpacked and a new page is created as requested ii Requesting temperature only through the WEB based interface The results are deliv ered by SMS to a mobile phone note that even in that case a WEB page is created This is the third protocol of the Section 4 2 2 iii The queries of experiment i and ii submitted through the WAP based interface Here the request of image and temperature as in i though the Wap interfaces is similar to the forth scenario of Section 4 2 2 Specifically for the above scenarios we measured the average preparation time required by the server proxy for sending the SMS messages to the camera and the overall response time measured from the moment that the user presses the submit button in the HTML or the WAP form until the moment that he she receives the corresponding results Roughly the average preparation time is the overhead introduced by the proposed middleware framework For the first experiment the results are shown in Table 5 7 For the default resolution the query protocol comprises a single SMS request message The average response time was 66 1 sec with a standard deviation of 18 sec When the resolution is set to high or compact an addit
74. message temperature alarm message y sets alarm message or for show Alarm message O Set low Temperature Alarm more info Temperature value only integers Celsius A leading minus is allowed I E 10 for STA value O Set Temperature Units more info Temperature measuring units Celsius Iv Set strong Wind Alarm more info wind speed in km h for SWA value Set Wind speed Units more info units for wind speed Km h y O Sets the GSM Telephone numbers up to 8 to which alarms will be sent more info is the TELephone position from 01 to 08 the 1st Telephone lv the telephone number maximum 15 digits including a the selected Telephone number Figure 4 1 Web based Interface for the Autonomous Weather Station 44 Request an SMS with weather data more info INitialize Initializes all parameters to the INIT default value more info NO Acknowledgment inhibits SMS acknowledgment more info Sets PIN for the SIM card more info 4 digits PIN code and for current value Software RESets the board more info Sets the GSM Telephone numbers up to 8 to which alarms will be sent more info is the TELephone position from 01 to 08 the 7th Telephone the telephone number maximum 15 digits including a the selected Telephone number 306947937714 last command submitted Sets the GSM Telephone numbers
75. n one SMS message Two Commands in Three Commands in Four Commands in we selected that the caller will send one command at the time and therefore there will be multiple calls of web services Then this program the WS Caller will collect the responses and send the SMS message with all the requested commands As mentioned the first type of implementation is given by the customizer by default and this type of customization was measured in Table 5 4 In the second type of implementation the Web Service proxy has the responsibility to send the SMS messages The WS Caller will sent all the requested com mands and their variables to the Web Service proxy and then waits We also evaluated this implementation for the same cases with the first implementation and the measurements are shown in Table 5 5 Without having installed the weather station the evaluation of the framework was based on the time needed from submitting the selected command s to be sent to the station until the indication that the commands were translated into SMS messages and were ready to be sent When the web service caller was used the total time of all the calls needed to the web service was measured If the Web interfaces the Html Form was used the page with the information about the submitted command s has that indication of completion This was shown in Figure 4 1 but in our measurement we omitted getting all the Html Form again as in Figure 4 2 The
76. n image is requested by the image SMS e 3 requests the current temperature with an SMS message to the phone that send this message e 11 1 11 2 and 11 3 changes image resolution to compact normal or high This is the case of changing resolution mode that was mentioned earlier 4 2 1 Interface and Implementation Details In the case of customizing the middleware for the observation camera the process is as de scribed for the weather station and the WEB Based interface is shown in Figure 3 6 for some of the camera functions commands Every function lead to different method in the proxy server and the interface is used for selecting and submitting the user requests But there is also the simple end user description of the sensor that has a different approach as shown in Figure 4 4 In the case of this description only frequently used functions are described and there are additional functions So the interface has the HTML Form for selecting the function the additional specification functions and then the delivery options Figure 4 4 There are in other words two parts in the interface the first includes the functions that the user has to select and the additional functions selecting for instance different resolution in the delivered images Figure 4 5 and the second part about the delivery information where the user selects the method of delivery with an e mail to a mobile phone Figure 4 6 and so on The customiz
77. n this description file leads to different services and interfaces The process of customization has two parts the creation of the proxy server and the creation of the corresponding user interfaces Every different command of the sensor results in a different method in the server that can be invoked by the client The cus tomization file describes three different user interfaces initialization information exchange and end user interface The proxy server in all these cases is the same In the evaluation we used three different files of sensor descriptions files with small medium and large number of commands in the cases of the initialization and information 56 Table 5 1 Customization time for the middleware framework in four cases according to the size of the sensor description file in number of commands described Customization 5 Commands 10 Commands 20 Commands 50 Commands process in sec Description File Description File Description File Description File Proxy Server i Web service proxy 0 39 0 55 0 65 0 98 ii Calling Interface creation 0 4 0 56 0 65 1 03 User Interface PAPA os om w w Total time of exchange interfaces We used descriptions with 10 20 and 50 commands The correspond ing proxy server is the same for these interfaces In addition a selection of the most used commands leads to end user descriptions with 5 commands We have measured the time for the customization of the server Table 5 1 i
78. ncludes all the customization measurement in the cases of the different description files The first row in the Table 5 1 has the results for the case of the server customization and the second row of this table has the results for the interfaces customization The average time of course is affected not only by the number of commands described but also by the complexity of these commands concerning the parame ters and variables that they might have The selection of the commands in the descriptions used was not random but the different kinds of commands had the same ratio in the cases of the descriptions with small medium and large number of commands The test set in the evaluation of 10 commands description file included three commands without any parameter or variable two commands with a parameter three commands with a variable and two com mands with a parameter and a variable The same ratio was used in the other cases of the sensor description files The average times for the creation are 1 95 sec for the 10 commands description file 2 33 sec for the 20 commands description file and 3 63 sec 50 commands description file For the creation of the interfaces initialization and information exchange the average time is 0 56 sec for the 10 commands description file 0 65 sec for the 20 commands description file and 1 03 sec 50 commands description file In the case of the 5 function end user we meas
79. nd the WEB page proxy is an issue tackled by the proxy server During the processing of a client request the proxy server waits for the creation of the result page at the WEB page proxy and then notifies the client The proxy server uses polling to realize the previous task While the client request is being processed a popup window is open at the client s browser Figure 4 7 highlighting the progress of the client s request 4 2 2 Protocols The clients of our application may then execute several query scenarios involving information provided by the mobile camera simply through the use of the generated interfaces and with out any particular knowledge of technicalities that relate to the particular camera All the required expertise on using the mobile camera is encapsulated in the logic of the server and the WEB page proxies generated by the mobile sensor customizer Following we examine 49 possible scenarios which are further evaluated in next Chapter 1 A client uses the HTML interface of the camera to obtain image and temperature delivered through a new page 2 A client uses the HTML interface of the camera to obtain image and temperature delivered to an e mail address Changing the image resolution mode to high or compact 3 A client uses the HTML interface of the camera to obtain temperature delivered to a mobile phone 4 A client uses the WAP interface to acquire image and temperature delivered through an
80. nds for installing the sensor the type of information that can be delivered by the sensor and alternative delivery methods Following the customizer generates appropriate WEB based interfaces and correspond ing implementations of server and WEB page proxies that mediate the interaction between clients and mobile servers Different kinds of sensors have different descriptions and capa bilities and so the behavior of the server and the WEB page specific proxies can vary For instance let us assume that a mobile sensor can send image temperature or both and this information can be delivered with an SMS or an MMS The SMS control sequences that 32 lt xml version 1 0 encoding UTF 8 gt lt l edited with XMLSpy v2006 U http Www altova con by Zissis E lt xs schema xmins xs http www w3 org 2001 XMLSchema elementFormDefault qualified attributeFormDefault unqualified gt lt xs element name sensor gt lt xs annotation gt lt xs documentation gt Sensor description lt xs documentation gt lt xs annotation gt lt xs complexType gt lt xs all gt lt xs element name html_Info type xs string minOccurs 0 gt lt xs element name init minOccurs 0 gt lt xs element name info gt lt xs complexType gt lt xs choice maxOccurs unbounded gt lt xs element ref infoRequest gt lt xs choice gt lt xs complexType gt lt xs element gt lt xs element name end user minOccurs 0
81. nt computer connecting the proxy server via an Internet connection These are the measurements in our first implementation type and those multiple web service calls lead to interaction time from 1 to 4 3 seconds in simple web service calls and 1 5 to 6 5 seconds through the Web User interface locally Using the second implementation type the average time in the different case are summarized in Table 5 5 The average time for web service call in this implementation is 1 1 seconds and through the Web User interface from 1 59 to 1 72 seconds are needed For the third set of experiments Table 5 6 i The number of requested commands in one SMS message varies as follows Requesting a simple command to be sent in one SMS message Requesting two commands to be sent in one SMS message 63 Table 5 6 Middleware overhead measurements in different case of requests in the Weather Station use case for our implementations with different sizes of description files 10 commands and 50 commands 3rd set of Web Service call User Interface locally Experiments Average time in sec Average time in sec lst 2nd implementation 1st 2nd implementation Simple Command in one SMS message 10 Comm Description 1 12 1 13 1 64 1 64 50 Comm Description 1 15 1 16 1 67 1 68 Two Commands in one SMS message 10 Comm Description 2 23 1 16 3 3 1 65 Three Commands in Five Commands in 10 Comm Description 5 6 1 2 8
82. obile sensor is determined by the manufacturer s specifications regarding command sequences for initializing the sensor and for selecting amongst alternative delivery methods and data contents The framework that is introduced is the Middleware Framework layer as shown in Figure 3 1 between different kind of GSM enabled sensors and data loggers which communicate data and the user interfaces From the variety of sensors and data loggers in front of sensors our middleware framework uses GSM GPRS technology to communicate with those GSM enabled devices This framework can be based on Web Services simple CGI scripts from html pages e mail servers or other proxy servers and in the implementation one of the above architectures or a combination between them can be chosen For instance we may use Web Services and an e mail server in cooperation The middleware will control and access the sensors loggers through the GSM GPRS network as shown at the bottom of Figure 3 1 and the interfaces of the users based in WEB or WAP in the top of that figure will access the middleware through the API that is provided Of course other applications industrial and domestic can access the GSM enable sensors through the user interface or the API of the middleware framework as an example with SOAP messages when a Web Services architec ture was selected for the implementation of the middleware framework 29 ln i pit te tm ti I Industrial and Domestic uses o
83. on can change a parameter a mode in the sensor and effect somehow an other function For instance a function can change the delivery parameters of the sensor e g change the resolution of the images delivered or that temperature will not be sent along with image and when an other function will have different effect when it will be executed maybe the delivered information will be different and in the case of resolution the delivered image will not be in default resolution This example is for the case of the observation camera but can easy lead to many interaction protocols in the use of the sensors for delivering data after modifying the delivery with changes as above This case is further detailed in the use case of the camera and is shown in the camera description file Figure 3 4 Of course for the same sensor there can be different description files when some one can add those interaction 38 protocols with the additional functions that can be used together Despite the formal de scription of the sensor that will be just like the manual of the function commands in an XML file those interaction protocols can be add a user perspective This fact will give a user friendly interface that will group together the functions and request form the sensor along with the use of popup windows in case of user requests as shown in Figure 3 7 a with links to the result pages as in Figure 3 7 b This part of the MSCD is called simple end user
84. on with Distributed Sensor Networks Computer Published by the IEEE Computer Society Vol 37 2004 M Maroti G Simon A Ledeczi and J Sztipanouits Sensor Network Applica tions Shooter Localization in Urban Terrain Computer Published by the IEEE Computer Society Vol 37 2004 B Hemingway W Brunette T Anderl and G Borriello The Flock Mote Sensors Sing in Undergraduate Curriculum Computer Published by the IEEE Computer Society Vol 37 2004 TinyOS An open source OS for the networked sensor regime http www tinyos net D Abadi D Carney U Cetintemel M Cherniack C Convey C Erwin E Galvez M Hatoun J Hwang A Maskey A Rasin A Singer M Stonebraker N Tatbul Y Xing R Yan S Zdonik Aurora A Data Management System demo description 2003 In proceedings of the 2003 ACM SIGMOD Conference of Management of Data San Diego CA H Balakrishnan M Balazinska D Carney U Cetintemel M Cherniack C Convey C Erwin E Galvez J Salz M Stonebraker N Tatbul R Tibbetts S Zdonik Retro spective on Aurora 2004 The VLDB Journal 2004 Digital Object Identifier DOI 10 1007 s00778 004 0133 5 A Arasu et al STREAM The Stanford Data Stream Management System http dbpubs stanford edu 8090 pub 2004 20 2004 The STREAM Group STREAM The Stanford Stream Data Manager IEEE Data Engineering Bulletin 26 2003 C Intanagonwiwat R Govindan D Estrin J Heidemann and F
85. onment should provide the appropriate applications and interfaces to utilize different kinds of sensors This is the concept of embedded Internet embedded deeper in any real environment using wireless sensor networks Developing such distributed extreme heterogeneous and embedded systems is a challenge To handle such distributed heterogeneous and oblique systems we shall adopt the approach of a Middleware Framework The ObjectWeb consortium gives the following definition of middleware In a distributed computing system middleware is defined as the software layer that lies between the operating system and the applications on each side of the system middleware objectweb org 1 Thus the term middleware is used to describe web servers application servers content man agement systems proxies wrappers and similar tools supporting the application development and delivery process The middleware is central to modern information systems based on XML SOAP Web services and service oriented architectures Our goal is to integrate a specific kind of sensor devices in a global computing environ ment These are GSM enabled sensors that can communicate and be instructed through the GSM network the network that any cell phone uses The term mobile phone is identical to the term cell phone so the term GSM enabled sensor is used alternatively with the term mobile sensor meaning the sensing device that wi
86. orm the above parameters has to do with latency depending on the CPU time needed e g in one of the server of the system and network communication time be tween different parts of the system Table 5 2 summarizes those latencies according to the parameter of the system that we can chose and shows the parameters that will be used in the experiments Specifically for the first set of experiments Table 5 3 59 Table 5 2 Parameters that effect Middleware overhead in the Weather Station use case and description of the following sets of experiments Parameter name Latency First set of Second set of Third set of Complexity of CPU time Different types Different types Different types Number of Commands One Command One two three One two three in the same Network time in one SMS or four Comm or five Comm SMS message message in one SMS mes in one SMS mes Two implementation Network time Different Different Different The means used CPU time server Different means Different means Different means Number of Commands 25 Commands 25 Commands 10 and 50 Comm described in CPU time server described in described in described in the MSCD file the MSCD file the MSCD file the MSCD file i The number of requested commands is the same in all the experiments of this set we requested one command in one SMS message ii The complexity of the command varies as described There are four types of commands and in our me
87. out animals plants and people This is an example of the applications that make use of sensors networks Nowadays the scale of the nodes in these sensor networks can be compared to the scale of the organisms under study and these networks are ranging in size from tens to thousands of different sensors nodes within a habitat patch Several real word deployments of habitat monitoring applications in the US and all over the world have leaded the development of a network architecture that is flexible enough and multilevel They make use of different kind of sensors grouped in patches networks involving nodes with heterogeneous sensing capabilities processing power and storage Habitat monitoring applications require ways to specify and deliver data of interest so they need routing and tasking service The data of interest can be either streaming or triggers and the task service has to cope with a dynamic topology of poor quality links potentially arbitrary termini sinks of data form nodes with minimal resources The low power mode of the system is needed for the long term operation and the current solution is duty cycling or changing the amount of time the subsystem is active during any given period at several levels The percentage of time each node is awake is known as the node s duty cycle and a variety of approaches are available for achieving low duty cycle operation Finally networks health monitoring and management are necessary
88. r provides compatibility with approaches for accessing mobile devices through WAP 38 WAP allows low end devices with limited CPU power memory and storage to access the wireless WEB which further suffers from frequent outages high latency and low bandwidth In addition to dealing with these constraints WAP was designed as an open standard like HTTP which significantly reduces compatibility problems across different vendor s imple mentations Besides being operating system independent WAP is also network independent and thus capable of operating seamlessly on top of any wireless transmission protocol The middleware framework developed in this work is reflective as it self customizes its interfaces with respect to constraints imposed by each particular sensor A middleware is said to support reflection if it is capable of 1 reasoning about both the application s re quirements over the middleware and 2 self customizing its properties or functionality to cope with the application s requirements This follows the very first definition of reflection given by Smith in 39 There are several middleware frameworks that expose the properties provided by the middleware services for introspection and change An example of such a 25 framework is Flexinet presented in 40 In Flexinet it is possible to modify the behavior of the middleware by adding and removing the reified request processing layers of the commu nication infrastructure
89. ramework Hence details about Nokia Observation Camera IRIDA BieneRemotel6 and Weather Station will conclude this introduction to commercial mobile sensors allie Figure 2 3 Nokia Observation Camera 15 2 2 1 Nokia Observation Camera Nokia Observation Camera is shown in Figure 2 2 and Figure 2 3 This camera is a remote imaging stand alone device with a motion detector thermometer and microphone Images can be captured and sent to any multimedia messaging MMS enable mobile phone with color display or to an e mail address Temperature can be sent after user request or if the temperature goes out of a set range the camera can be also programmable to take images automatically at a designated time interval or when the motion detector is triggered Finally the microphone can be used to listen to the environment that the camera is installed into The site for the Observation Camera Support is 27 and the user manual can be found there Table 2 2 An example of Nokia Observation Camera instructions note the underline char acter _ is used for space in the SMS message Task SMS Command Capture an image and send it to your 1 or image EPI 1_phone number e mail address or phone number or e mail address image_phone number e mail address Set the image resolution to high 1 11_number normal 2 or compact 3 3 01 or detection Set the sending of current 13_on off Set connection security on or off
90. rding the various content types and at tributes either graphically through HTML or WAP based pages or though a programmable WSDL interface Then the client preferences are properly handled by the corresponding proxy servers Finally there are also common and useful interactions with the sensors Those interactions are consisting of a number of initiation and information query requests of SMS messages described in case of the end user protocols end user_description tag in Figure 3 3 and can provide different and simple interfaces What is why those protocols are called end user protocols and provide end user interfaces Hence to integrate a mobile sensor in our global computing environment we define an XML scheme that describes the structure of MSCDs We can then describe all mobile sensors by providing MSCDs that comply to this scheme A representative MSCD example is given in Figure 3 4 which is further detailed later in Section 3 4 and in the use cases given in detail in next Chapter 35 3 3 Server and WEB Page Proxies The behavior of proxy servers is rather typical as it materializes the alternative initialization and query protocols specified in the MSCDs that were used for generating the servers In particular a proxy server collects requests for information issued by clients and translates them into sequences of sensor specific requests such as SMS messages For the requests to the proxy there are the appropri
91. re Technology of Wireless Sensor Networks 2 1 3 Networking and Query Processing in Wireless Sensor Networks 2 1 4 Security and Privacy in Wireless Sensor Networks 2 2 Commercial Mobile Sensors 2 2 1 Nokia Observation Camera 2 2 2 IRIDA GSM 2 2 3 BieneRemotel6GM 2 2 4 TCS AWS GSM autonomous weather station 2 3 Middleware Web Services and Messaging 2 1 Wireless Sensor Networks Technology that is commercially available today gives rise to engineering efforts that have produced complete devices with processing storage sensing and communication functions 4 devices that are smaller and cost less The last 50 years a new class of computers has appeared about once a decade modern computing is progressing through mainframes mi crocomputers personal computers and mobile computers Each successive model relies upon technical advantages to make computing available in a way not previously possible Each has introduced new uses for computer technology and each succeeding generation is smaller more plentiful and more intimately associated with personal activity than the generation that proceeded it Wireless Sensor Networks WSN appear as a new class they follow the same trends of size number and cost but rather than being devoted to personal productivity tasks they make it possible to perceive what takes place in the physical world in ways not previously possible One can consider Wireless Sensor Networks as Thousands of t
92. relessly transfer data through the GSM network Specifically we focus on GSM enabled sensor devices controlled by SMS messages that exchange information through SMS or MMS messages Besides using the proprietary communication protocols usually SMS messages and the specific characteristics of the mo bile sensor we provide the means to integrate different mobile sensors in our computing environment The work presented in this thesis proposes a middleware framework that enables uniform access to mobile sensors We introduce a mobile sensor description that is used to configure the middleware according to the sensor specifications and to provide the interface for access ing the mobile sensor The remaining of this thesis is structured as follows Chapter 2 provides a brief overview of Wireless Sensor Networks a survey of mobile sensors for industrial and commercial use and discusses similarity to our work from the middleware prespective Chapter 3 describes our middleware framework discusses the process of customization based on a proposed sen sor description standard the system architecture and finally presents implementation issues Chapter 4 details the use cases of mobile sensors Chapter 5 presents performance evaluation results and finally Chapter 6 offers conclusions CHAPTER 2 WIRELESS SENSORS AND SENSOR NETWORKS AN OVERVIEW 2 1 Wireless Sensor Networks 2 1 1 Applications Issues in Wireless Sensor Networks 2 1 2 Hardwa
93. rent type in the same SMS is a decision that leads to more simple experiments 4 6 4 and one cases This decision will not effect the general idea of the selection of multiple commands in one SMS message ii The complexity of the command varies as in the first set and in our measurement we have the average time iii We used both the two implementations iv Finally same as in the first set of experiments we make use Web Services calls the Web Interface locally and through Internet connection and the MSCD file described 25 commands We performed the experiments with two different types of implementation that were dif ferent in the inner communication of the proxy server The Web Service caller WS Caller is the part of the proxy that communicates with the Web Service for the commands and gets the response When multiple commands are selected to be sent the number of commands that can be submitted from the WS Caller can be one by one or all of them The first type of implementation is the simple type that the customizer creates In that implementation 61 Table 5 4 Middleware overhead measurements in different case of requests in the Weather Station use case for the first type of our implementation 2nd set of Web Service calls Web Interface Web Interface Experiments locally Web page locally Internet connection first implementation Average time in sec Average time in sec Average time in sec Simple Command i
94. resses the issue of accessing transparently mobile sensors through a customiz able middleware framework Sensing monitoring and controlling devices and techniques have been used in industry for many years The evolution of microcomputers along with Moore s law and the increas ing needs for sensing and controlling in our complex environment have led to new sensing devices being smaller cheaper and capable of applications that it was impossible to realize ten years ago This new area of research and development is known as sensor networks or Wireless Sensor Networks WSN because is more useful and frequent to communicate with hundreds of those sensing devices wirelessly Wireless sensor networks consist of hundreds of self contained battery powered computers that measure and communicate wirelessly en vironmental data They are embedded in the environment can act proactively and can be presented as a new tier in the Information Technology ecosystem Those abilities im prove the proactive computing and pervasive computing or ubiquitous computing paradigms In proactive computing computers anticipate human needs and act on human s behalf Pervasive computing refers to the next generation computing environments with in formation and communication technology everywhere for everyone at all times A global computing environment built on top of the Word Wide Web can integrate sensing devices A global computing envir
95. rogramming the devices with a computer is custom made for the devices with serial port connection except from the BieneRemotel6GT which supports only SMS programming The sensing types that the devices can measure are depending on the devices the mobile camera can capture images and get current temperature the data loggers have analog and digital inputs and the weather station can measure wind direction and speed temperature humidity and rainfall Of course the number of outputs for activation 23 Table 2 6 Classification of the above four sensors DT Observation Camera IRIDA GSM BioneRemoisi GM TOS AWS sensor or sensor data logger data logger full system sensors data logger and data logger GSM GPRS GSM GPRS GSM SMS GSM GPRS opt PC connection Custom made software Custom made software only SMS PC Software and programming serial port serial port and programmable TCS OS RS 232 SMS programmable sensing types image and temperature analog digital analog digital signals weather measure signals and temperature for ments wind 16GM 2SMT ver temp rainfall etc motion detection alarm messages event notification wind temperature temperature alarm rainfall alarms and alarm messages master user users supervisor users administrator with privileges and access code and users use and security code of passwords external power supply external power supply external power supply wide power supply range and battery
96. rs for enabling gateway nodes to bridge to legacy networks Despite significant differences in device capabilities the overall architecture for the classes of sensor networks platforms is remarkably similar This similarity follows from the require ment that they seamlessly follow from the integrate wireless networking Network support must be transparent and self configuring to allow sensor networks to scale in size and com plexity The engineering decisions about the amount of on board memory the amount of CPU processing power the type and bandwidth of wireless link determine the cost and power consumption which influence the final design of any given sensor node Additionally Moore s law and the development of advanced wireless sensor networking platforms influence the age of ubiquitous sensing and actuation and as capabilities are improving these systems will be able to automatically act on sensor data to manage our environment for years at a time in potentially hostile environment without hope of human intervention Our work is orthogonal to communication and power considerations The mobile sensors in our work are at an upper level to the typical micronodes as those of the third and forth level of Table 2 1 according to their capabilities and they have additional computing power and storage capacity They have specific functions and usually custom made operating sys tems with the use of control SMS messages or with a serial port
97. s on each side of the system Our goal is to integrate a specific kind of sensor devices in a global computing envi ronment These are GSM enabled sensor devices that can communicate and be instructed through the GSM network the network of cell phones Specifically we focus on sensors controlled by SMS messages that exchange information through SMS or MMS messages We provide the means to integrate different mobile sensors in our computing environment by using the proprietary communication protocols usually SMS messages and the specific characteristics of the mobile sensor Starting from GSM enabled devices we automate the process of integrating these devices in a global computing environment with the use of XML based sensor descriptions To this end we proposed a customizable middleware framework was proposed vi IIEPIAHVH MSc 2006 A Customizable Middleware Framework for Accessing Mobile Sensors H xal xal
98. t lt altemBody gt ALR status lt altermbody gt lt messageVar gt lt choices gt lt choiceDescription gt changes status or gets current status for generation of an Alert SMS lt choiceDescnption gt lt choiceName gt status lt choicename gt lt choceValue gt ON lt choiceValue gt lt choiceValueDescr gt enable lt choiceValueDescr gt lt choiceValue gt OFF lt choiceValue gt lt choiceValueDescr gt disable lt choiceValueDeser gt lt choiceValue gt lt choiceValue gt lt choiceValueDescr gt get status lt choiceValueDeser gt lt choices gt lt messageVar gt lt SMS gt lt messageType gt lt message gt lt infoRequest gt lt infoRequest gt lt message gt lt description gt NO Acknowledgment inhibits SMS acknowledgment lt description gt lt messageType gt lt SMS gt lt body gt W NOA lt Dody gt lt alterndody gt lt order gt 0 lt order gt lt messageVar gt lt SMS gt lt messageType gt lt message gt lt infoRequest gt lt infoRequest gt lt message gt lt descriptian gt Sets the GSM Telephone numbers up to 8 to which alarms will be sent get telephone description gt lt messageType gt lt SMS gt lt body gt TELxxtttttttttttttt lt body gt lt order gt 0 lt order gt lt altemBody gt TEL 7 lt alttembody gt lt messagaVar gt lt choices gt lt variable gt lt variableName gt tttttttttttttt lt variablename gt lt varDescription gt th
99. t developing and testing a non invasive sensor system for tracking wildlife http www environcenter hmc edu research lizardnetreport pdf 2005 The Sensor Web Project NASA s Volcano Sensorweb http sensorwebs jpl nasa gov Delin S P Jackson S C Burleigh D W Johnson R R Woodrow and J T Brit ton The JPL Sensor Webs Project Fielded Technology In Space Mission Challenges for IT Proceedings Annual Conference Series 2003 R Doyle An Autonomous Earth Observing Sensorweb IEEE Intelligent Systems 2005 http www computer org intelligent A Mainwaring J Polastre R Szewezyk D Culler and J Anderson Wireless Sensor Networks for Habitat Monitoring In Proceedings of First ACM Workshop on Wireless Sensor Networks and Applications 2002 Habitat Monitoring on Great Duck Island Introduction http www greatduckis land net CORIE EOFS project that is studying Oregon s Columbia River http www ccalmr ogi edu CORIE about html Envisense The Next Wave Centre for Pervasive Computing in the Environment http envisense org 76 12 13 14 15 16 17 18 19 20 21 22 K Martinez J K Hart and R Ong Sensor Network Applications Environmental Sensor Networks Computer Published by the IEEE Computer Society Vol 37 2004 S M Brennan A M Mielke D C Torney and A B Maccabe Sensor Network Appli cations Radiation Detecti
100. t messageType gt lt messageType gt lt message gt lt message gt lt initialization gt lt subType gt lt initialization gt lt message gt lt message gt lt description gt Change image resolution mode lt description gt lt description gt ask for the IMEI code and software and hardware versions of the lt messageType gt camera lt description gt lt SMS gt lt messageType gt lt body gt 11 mode lt body gt lt message gt lt order gt 1 lt order gt lt initialization gt lt messageVar gt lt initialization gt lt choices gt lt message gt lt choiceDescription gt the resolution mode lt choiceDescription gt lt description gt Enable or disable sending current temperature with images lt description gt lt choiceName gt mode lt choiceName gt lt messageType gt lt choiceValue gt 1 lt choiceValue gt lt message gt lt choiceValueDescr gt compact lt choiceValueDescr gt lt initialization gt lt choiceValue gt 2 lt choiceValue gt lt initialization gt lt choiceValueDescr gt normal lt choiceValueDescr gt lt init gt lt choiceValue gt 3 lt choiceValue gt lt info gt lt choiceValueDescr gt high lt choiceValueDescr gt lt infoRequest gt lt choices gt lt infoRequest gt lt messageVar gt lt message gt lt SMS gt lt description gt Request the current temperature lt description gt lt messageType gt lt messageType gt lt message gt lt SMS gt lt
101. terface for the Autonomous Weather Station after submitting one command to the sensor dit a Autonomous Weather Station dad pre Bk ee Web based Interface for the Nokia Observation Camera in the End user simple cases lt u Ages En A Filling delivery information 2 8 E20 2 gt LESE a ee Ek ee Ah Setting up delivery destination zu a ua a ka a a a Kar aa ill 13 15 15 17 20 23 30 32 33 34 39 36 37 44 45 46 48 49 49 AT A A he eS 4 8 4 9 R s ltsp fes agird a due Pe ea her Using the WAP interface in the forth scenario 4 10 Query protocols for the two scenarios 5 1 5 2 5 3 5 4 5 9 1 Customization Process of different description files Middleware Overhead Measurements for 10 Commands description file Middleware Overhead Measurements for 50 Commands description file Breakdown of overall response time for experiment i Breakdown of overall response time for experiment ii and iii Part of the GSM Autonomous Weather Station description file LIST OF TABLES 2 1 232 2 3 2 4 2 9 2 6 5 1 5 2 5 3 5 4 5 9 5 6 5 7 5 8 5 9 Sensors hierarchy in wireless sensor networks each platform class handles dif ferent types of sensing A An example of Nokia Observation Camera instr
102. though well defined WEB enabled interfaces 28 Several emerging technologies exist for the development of such interfaces In practice in our work we meet HTML based interfaces that facilitate the communication between devices like personal computers and laptops and WAP based interfaces that support the communi cation in environments involving hand held devices like PDAs and pocket PCs Nowadays we further have the ability to use programmable interfaces such as the CGI scripts and rely on the standard Web Services architecture 36 44 In this chapter we specifically focus on incorporating in such global computing environ ments as in 45 small GSM enabled sensor devices controlled by SMS messages Typically information gathering from mobile sensors is performed through either SMS messages e g temperature atmospheric pressure or humidity or MMS messages e g images video or time varying signals of seismic or electromagnetic activity SMS messages are traditionally used as means not only for controlling GSM enabled devices and logging data regarding their operation e g the status but also for requesting information e g temperature or wind speed A sensor specific proxy server collects client requests for control logging or informa tion and submits them to the sensor Then it collects the specified response and information and makes it available in client compatible formats The interaction between the proxy server and the m
103. tion Use Case After customizing the middleware for the case of the autonomous weather station we can measure the time overhead that the middleware introduces in different cases of accessing this sensor This overhead depends on e The complexity of the requested commands as there are commands without parameters or variables commands with parameters or variables and commands with parameters and variables For instance there are commands without parameters or variables e g GTM or NOA as in Section 4 1 commands with one parameter e g ALR to enable or disable the generation of an alert SMS with the parameter status to be enable disable or commands with one variable e g CUP for changing a user password with the password as a variable and commands with a parameter and a variable e g TEL as described in Section 4 1 e The number of requested commands to sent in the same SMS message to the sensor e The means that will be used to select and translate the commands to SMS message s as it is possible that the user can utilize the middleware with Web Services calls or through the Web Interface Moreover there are two different implementations that were detailed in Section 3 4 and each of them introduces different delays in the system e The number of commands described in the MSCD file for the middleware customiza tion as it will be detailed in the last set of experiments The overhead f
104. transformation over the data Queries are written in a SQL like language they are the input on a PC that sends the query into the sensor network and a number of optimizations are might applied by the query processor Common ground between TinyDB and Diffusion is a query language interface for network processing and in some cases tend to give users more control over the types of network topology and patterns of communication In our work there two different networks involved the GSM network of the mobile sen sors including GPRS for communication based on packet switching and the Internet with the web interfaces and the servers of our customizable middleware This middleware frame work is responsible for the execution of any information request and the utilization of those different networks However future systems will be more sophisticated than any of today s prototypes and will involve many novel network requirements The basic dimensions of design in terms of networking mechanisms are scope concerning the nodes involved in a query volume i e communication cost per unit time complexity concerning multiple concurrent queries timeliness having to do with delays between events and quality of the query response The 11 fact is that network aware for query processing is in its infancy multiple complex queries must be supported beyond the basic tree based data collection more sophisticated topology construction algorithms and
105. tute the proposed framework To demonstrate our overall approach for unifying access to mobile sensors in global com puting environments we provide a specific instances of our architecture that allows accessing a mobile camera described in Section 2 2 1 through multiple WEB based interfaces and the GSM autonomous weather station as described in Section 2 2 4 Those are the use cases that will be described and evaluated in the next chapters First we present in details the different parts of our framework 31 Application Server Mobile Server Customizer FA te a i u u DA E Mobil i obile A 4 o Mobile Sensors wo Phone 9 te Clients e gt Ya Figure 3 2 System Architecture 3 2 Mobile Sensor Customizer As we discussed in Section 3 1 the interaction between clients and mobile sensors is deter mined by the manufacturers specifications regarding command sequences for initializing a sensor and for selecting delivery methods and data contents Unifying the communication between clients and mobile sensors by providing appropriate WEB based interfaces is a major issue in this context Addressing this issue is the main responsibility of the mobile sensor customizer The customizer accepts as input a MSCD provided by means of an XML file Roughly the Mobile Sensor Control Description MSCD specifies besides control messages as for instance initiation comma
106. uctions note the underline character _ is used for space in the SMS message Some of Irida GSM instructions be ged a Nes Kou ae de o An example of GSM SMS Remote Control Module BieneRemotel6 standard version control commands Sad aida eit Se Gee a ga TCS AWS GSM Autonomous Weather Station some of the commands in DS MESES is Gt a ae ee eo eo AAA AA Classification of the above four sensors 2 2 2 on mn nn Customization time for the middleware framework in four cases according to the size of the sensor description file in number of commands described Parameters that effect Middleware overhead in the Weather Station use case and description of the following sets of experiments Middleware overhead measurements in the case of one command in one SMS message in the Weather Station use case Middleware overhead measurements in different case of requests in the Weather Station use case for the first type of our implementation Middleware overhead measurements in different case of requests in the Weather Station use case for the second type of our implementation Middleware overhead measurements in different case of requests in the Weather Station use case for our implementations with different sizes of description files 10 commands and 50 commands 2 ode 23 22 dea a Response time and middleware overhead for experiment i Response t
107. ure 0 39 sec in average and in 5 commands description file the initialization interface 57 Customization Process O web service proxy creation a it 5 2 o v 5 Ed a calling interface creation DO user interface creation 2 00 Time in sec Figure 5 1 Customization Process of different description files was created in 0 41 sec in average The third row of the Table 5 1 has the time for the customization of the Java files needed for the proxy server the Web Service caller Java file and the interfaces the servlet file Those measurements were added to total creation time Figure 5 1 also shows the customization process for four cases according to the size of the sensor description file in number of commands In this figure the process time is divided into three parts the time for creation of the proxy server the web interface and both the WS Caller and the servlet Summarizing as it is shown in the related table and figure Table 5 1 and Figure 5 1 someone can provide the interfaces and the proxy server within some seconds depending on the number commands which are described in the MSCD file The files created can be used after compilation and copy in the directories of the server that is used Tomcat server for the servlets and Axis for the Web Services need some configurations and then service and user interface will be ready 58 5 2 Middleware Overhead in the Weather Sta
108. vered Wait for the information a at the web request to be is delivered wet Dre To e mail processed request to Be e i rocesse y Popup Windo p MMS or SMS message Information delivered and posted Visit the web page with Web Browsing the results a Scenario 1 b Scenario 4 From the client Web Browsing and the CGI Get from client to application server From the server or the sensor SMS or MMS Messages Popup Window events opening completing 1 Communication within the application server while the request is being processed Process completion Query protocol notation Figure 4 10 Query protocols for the two scenarios 54 CHAPTER 5 PERFORMANCE EVALUATION 5 1 Customization Overhead 5 2 Middleware Overhead in the Weather Station Use Case 5 3 Middleware Overhead in the Camera Use Case In this chapter we evaluate the prototype middleware framework that accesses GSM enabled sensors In Section 5 1 we measure the middleware customization time In Section 5 2 we evaluate the time overhead that the middleware introduces in the case of a mobile weather station Finally in Section 5 3 we evaluate the middleware time overhead in the case of the mobile camera 5 1 Customization Overhead The customization process is performed once for each sensor type according to the cus tomization MSCD file Every subsequent change i
109. verhead in the Weather Station Use Case 5 3 Middleware Overhead in the Camera Use Case 6 Conclusions and Future Work Bibliography Appendix Author s Publications Short CV il 56 56 59 67 73 76 80 84 86 LIST OF FIGURES 2 1 2 2 2 3 2 4 2 5 2 6 3 1 3 2 3 3 3 4 3 9 3 6 3 7 4 1 4 2 4 3 4 4 4 5 4 6 GSM Remote Monitoring and Alarm System XR5 Data Logger for pressure temperature level flow weather power vibration etc with the use of GSM Modem Wavecom WCOD2 GSM Nokia Observation Camera sending MMS or e mail messages with image and temperature datan dde dias da ee Beh Nokia Observation Camera 2 2 a a are IRIDA GSM from Autotech GSM SMS Remote Control Module BieneRemotel6GM Installed GSM Autonomous Weather Stations Architecture Layers ARAS AAA AO A OY System u ae The XML schema tor MSCDs 24 3 2 8 rer a Example of a MSCD specification for a mobile camera Web based Interface for the Autonomous Weather Station part of the initia tion commands tdo eo do N tt ak ASS oN E gd 2 Web based Interface for the Nokia Observation Camera some of the commands of the mobile camera that be selected End user case for mobile camera Web based Interface for the Autonomous Weather Station Web based In
110. verhead of the web service calls needed in the first implementation even more This is shown in Table 5 6 comparing 10 to 50 commands description files and would be even clear in 10 to 100 commands comparison and more complex in terms of parameters and variables Figure 5 2 shows the middleware overhead measurements for 10 command description file when web service calls are used In the figure we measure the first and second imple mentation in the cases of different number of commands in one SMS message Figure 5 3 shows the same measurements for 50 command description file when the Web interface is used To conclude in the case of the Autonomous Weather Station someone can use the web interface or just call a web service requesting data or changing a sensor parameter e g the wind speed measuring units with a control message The time for this use case and the over head in the user requests was measured and detailed in the related tables and figures from Table 5 3 to Table 5 6 and in Figure 5 2 and Figure 5 3 for two different implementations Cases of different kind and number of commands requested was also measured A couple of seconds are enough for the translation of the user requests into SMS messages The overhead 66 Middleware Overhead Measurements 50 Commands Description through Web Intreface 1st impl through Web Intreface 2nd impl A Time in sec ho E mn o co wo N n simple
111. wser Finally Table 5 9 presents the results for the last experiment i e accessing the camera from the WAP interface to get a image and temperature with default resolution delivered in a WEB page b just temperature delivered to a mobile phone and an extra experiment c get temperature to the same Wap Browser Figure 5 4 and Figure 5 5 summarize our results Specifically the overall response time is divided into the time required for the preparation of the SMS request messages at the proxy server vertical lines and the time required for the preparation and the delivery of the MMS reply from the camera to the client or to the WEB page proxy gray Observe that the processing time introduced by our framework at the proxy server is almost the same in every experiment The remaining overhead depends on the network latency The large standard 69 Response Time in Mobile Camrera Use Case 175 0 El processing at proxy server to prepare control SMS OMMS delivery unpacking and web page creation 150 0 125 0 100 0 75 0 Time in sec Experiment i for three resolution modes Figure 5 4 Breakdown of overall response time for experiment i deviation is due to the GSM GPRS network traffic and communication parameters In the case of multiple user requests at the same proxy server the response time could increase significantly To resolve this bottleneck we ma
112. y Using a V in front of the number example TELO1 V34822334xxx will cause the TCS unit to place a call for 20 seconds and not send an SMS This is a command that has a parameter for the position of the telephone number with values form 01 to 08 and a variable that is the telephone number as mentioned above with or with out V Note that the V can also be a parameter an option given to the user in the case of placing a call for 20 seconds e A command that can be the end of a SMS command string is NOA meaning NO Acknowledgment and with using this there will be no return SMS acknowledgment In the case of NOA there are no parameters or variables Those examples will help us understand the customization of the middleware in the case of the autonomous weather station and the process that will map the described commands of a sensor in the MSCD file to the corresponding user interface options and server functions 43 Distributed Systems Lab University of Ioannina Please fill in all necessary fields for the Commands Initiation commands Selects access mode for Voice call function more info Chooses Function available upon voice call Free Access lv O Enables ON or Disables OFF the genaration of an Alert SMS more info changes status or gets current status for generation of an Alert SMS enable O Stores and reads text for programmable Alarm Messages more info changes alarm
113. y use more than one proxy servers and or multiple sensors at the same point Response Time in Mobile Camrera Use Case Bresponse time for WAP access 4 175 0 processing at proxy server to prepare control SMS 150 0 mMMS delivery unpacking and web page creation 125 0 gt a 100 0 750 50 0 25 0 0 0 getting temperature at getting image and getting temperature by mobile phone ex ii temperature by WAP at WAP at mobile phone web page ex iii exc iil Experiments ii and iii Figure 5 5 Breakdown of overall response time for experiment ii and iii To conclude the mobile camera can deliver the requested data to an e mail address a mobile phone number or to a new web page created for this case The overhead that was 70 measured from 15 to 25 seconds depending on the number of control SMS messages needed for user request in our case one or two messages were needed The information was deliv ered after a little more that a minute after the submission of a request with the exception of the request of a high resolution image that could double the time 71 CHAPTER 6 CONCLUSIONS AND FUTURE WORK Wireless Sensor Networks is a new area of research and development Wireless sensor net works consist of hundreds of sensing devices embedded into the environment that measure and communicate wirelessly environmental data Through the use of Wireless Sensor

A Customizable Middleware Framework for Accessing Mobile Sensors

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