The Information Furnace: Consolidated Home Control
Contents
1. Thankfully having the PBX connected to the information furnace one can easily package this functionality as a shell script and have another script program the PBX quick access memories to a known state John Doe Home setmem 10 0105554321 John Doe mobile number setmem 11 0935551234 John Doe Office setmem 12 0105556789 Since this script is rarely used I did not provide a more elaborate interface to it al though the script could easily be generated by mining the PDA phone database backups or through web forms However even in the format it currently is it proved a time saver when the country s numbering plan changed a simple global replace operation in the editor resulted in a new script that when run correctly programmed the PBX memories for the new plan 17 XY MP3 Playlist Netscape M x lt MP3 Playlist Netscape l0j x File Edit view Go Communicator Help File Edit view Go Communicator Help Ndel o kaipdg 2303 OGd oveipwy 72304 Ei antag ywp prepa 72305 Eylve Trape qynon 72306 H kupa 72307 Egra tpayoudia 6a cou Tw 42308 ayartw 42309 Fapugadao ot auii 72370 Mia Navayie 72394 T agt pi tou Ropn 2372 O tayu p po m ave 12313 To paA twv yap vwv oveipwv 12344 Koupagp vo TaA nk pi 42315 Aydt Trou yive SikoTTo payaip 72376 H Aat pva 42377 O apa 72378 AB va 12319 Ndel puye 10 1paivo 42320 Ta Traldia to2. design philosophy While my prototype implementation proves the concept its piecemeal implemen tation by a single developer has resulted in a wanting to put it politely software ar chitecture If the information furnace concept is to be widely adopted major architec tural challenges have to be overcome Already research approaches such as iRoom 22 demonstrate how the task of developing such an architecture could be approached Mass produced hardware for information furnace applications should be uniquely tai lored to the special needs of its domain in our implementation we found that a large number of digital and analog I O ports and appropriate network interfaces were more useful than raw processing power Similarly the software architecture of a consumer oriented information furnace should be extremely reliable allow installator and end user customisation provide means for interfacing to many different proprietary devices and integrate the above with a modular multi modal and easy to use interface Context awareness issues need to be carefully examined and resolved 74 What is not needed is a repeat of the PC usability and reliability debacle in a scale that will affect our entire family lives and home Acknowledgements Compaq Research contributed as a prize of the 2000 Usenix technical conference win a pet Shark contest the Digital Network Appliance Reference Design DNARD that I used as the system s first
3. hu Oct 17 2002 11 15 47 alarm trigger Kitchen disabled hu Oct 17 2002 11 16 02 last message repeated 14 times hu Oct 17 2002 11 17 36 alarm trigger DiningRoom disabled hu Oct 17 2002 11 17 37 alarm trigger DiningRoom disabled hu Oct 17 2002 11 17 38 alarm trigger Entrance disabled hu Oct 17 2002 11 17 38 alarm trigger DiningRoom disabled gt Date Time From Thu Oct 17 2002 09 55 omice Print _ Delete Delete all Incoming Calls saa a 545554545 Line Voltage hu Oct 17 2002 14 03 33 234V hu Oct 17 2002 14 04 33 234V hu Oct 17 2002 14 05 33 234V hu Oct 17 2002 14 06 33 232V hu Oct 17 2002 14 07 33 232V zl Date Time From Thu Oct 17 2002 22 44 John Smith Call back Internet Connection Actions Open door Test siren 1 Test siren 2 Document Done 3 a aP a l 4 S Document Done zE Currently up since Thu Oct 17 2002 22 45 _ Terminate Figure 8 Web based interface to communications and security functions 23 development described in this paper were to demonstrate the technical viability of the proposed setup and provide an experimental test bed to investigate the synergies emerg ing from the service co location User interface improvements should naturally surface once devices were freed from the artificial constraints imposed by their hardware tiny displays primitive input devices and limited communication capabilitie
4. s conceptual model and current state are hidden from the user and there are no natural mappings between a user s intentions the required actions and the resulting ef fect Similarly many of the user interface design Golden Rules 9 pp 74 75 are never followed interfaces are inconsistent require tedious sequences of data entry and often lack shortcuts informative feedback and the ability to reverse actions Other impor tant user interface problems include non intuitive interaction sequences the operation in various different modes 10 pp 30 57 the overloading of buttons for different purposes cryptic display messages lack of localisation and accessibility for disabled people and a non ergonomic design Appreciating that I might be accused of shooting a lame duck I illustrate these points with three representative examples Programming a Heating Controller The room unit in question allows programming a weekly schedule for the controller s operation Programming is performed by opening the room unit access panel to reveal a numerical menu and switching between its 17 different modes see Figure 1 The fol lowing excerpt from the operation manual outlines the weekly programming procedure 11 p 5 With the heating program you can predetermine the temperature switch over times for one week The weekly program consists of seven 24 hour programs One 24 hour program may include up to three heating periods each of
5. 64 65 66 67 68 69 70 71 72 73 74 Konstantinos Chorianopoulos and Diomidis Spinellis A metaphor for personalized televi sion programming In Proceedings of the 7th ERCIM Workshop on User Interfaces for All Paris Chantilly France October 2002 Springer Verlag Maria Tsakali and Ioannis Kaptsis Cross media content production and delivery trends and challenges In Proceedings of the 2002 Euro China Co operation Forum on the Infor mation Society 2002 Pattie Maes Artificial life meets entertainment Lifelike autonomous agents Communi cations of the ACM 38 11 108 114 November 1995 Barbara Hayes Roth An architecture for adaptive intelligent systems Artificial Intelli gence 12 329 365 1995 Special Issue on Agents and Interactivity Jaron Lanier Agents of alienation ACM Interactions 2 3 66 72 1995 Alistair D W Edwards Extra Ordinary Human Computer Interactions Intefaces for Users with Disabilities Cambridge University Press 1995 Alfred Z Spector Challenges and opportunities in autonomic computing In Proceedings of the 16th international conference on Supercomputing pages 96 96 ACM Press 2002 Emma Duncan There s nothing on The Economist October 5th 2000 Survey on e Entertainment Donald A Norman Home theater Not ready for prime time Computer 35 6 100 102 June 2002 Su Shing Chen The paradox of digital preservation Computer 34 3 24 28 M
6. The 80Gb hard disk is used to store music content in MP3 form to distribute throughout the house and as intermediate storage for backup purposes PCs and MP3 players connect to the infor mation furnace via an Ethernet local area network LAN The GSM phone and a UPS both connected to the information furnace via serial links provide communications and power backup Connecting the alarm system devices to the furnace was more challenging Alarm 14 Figure 4 The information furnace left and the sensor connection PCB right sensors and actuators typically work with 12V voltage while the digital I O card I used provided an 8255 compatible TTL type interface on a 50 pin ribbon cable connector To match the physical form and electrical characteristics of the two systems I designed and implemented a simple printed circuit board PCB circuit that converts sensor signals into TTL compatible inputs uses relays to activate external loads and provides screw clamp terminal blocks for connecting the sensors and sirens Figure 4 right 5 2 Home Security The information furnace s alarm subsystem consists of a device driver that interfaces to the PCL 724 card and a daemon that monitors sensors and reacts to signals and com mands The user mode alarm daemon is structured around an event driven driven loop Three types of events are handled e external commands e g arm disarm panic e sensor inputs and e elapsed timers used for p
7. a tough platform for MP3 decoders I fortunately was able to choose and test several different packages until I settled for the MAD MP3 decoder the only one that run suc cessfully on the Shark A counterexample was the vgetty package as far as I could determine it is the only viable offering for handling voice modems and it has a lot of room for improvement At the start of the project I was somewhat ambivalent on binary and package distributions However I found that being able to quickly try pack ages without having to go through the configuration and manual compilation process 21 outweighed the opacity problems of this distribution process 6 2 Standards and Costs The existence of open standards proved to be a blessing for the project s success the lack of standardisation a curse Specifically the lack of open standards ruled out having the information furnace controlling the home s heating in the form I described the heating controller was clearly attached to a form of a network bus but its operation at all the network stack levels was apparently a secret closely guarded by its manufacturer i e the standard was not available on the web Similarly in the domain of artificial lighting controls it being an area where a number of incompatible proprietary standards compete there are expensive solutions that do not deliver the economies they could Efforts for integrating arbitrary communication protocols such as 54 could help s
8. for the prescribed duration of a trip Instead of a burner some systems are based on a heat pump and air circulation They are controlled by the same principles but can also lower the building s temperature during hot days Split type wall mounted room air conditioners feature an integrated opaque control circuit adjusted individually through a remote control The provision of hot running water to the bathrooms and kitchen is often controlled together with the central heating system The added complications this brings into the picture involve the possibility of heating the water on sunny days through a solar panel an electrical heater used as a backup measure a circulating pump to pass water through the solar panel and a second pump to bring hot water near the taps The first pump operates through a thermostat comparing the temperature difference between the hot water storage tank and the solar panel we can again regard the system as a black box that absorbs solar energy The operation of the second pump is more tricky its intention is to save water by bringing the hot water close to the taps When the central heating system is operating having a secondary warm water circulating circuit in the house does not hurt the floors and walls where the running hot water pipes run act as secondary radiators When however the central heating is switched off on warm days or during an absence the circulator actually cools the stored warm water by conti
9. for the main unit NetBSD with its multiple architecture support was at the time the only OS that supported the Shark s StrongARM architecture while the aggressive development model of Linux resulted in an installation procedure and the existence of device drivers that could revive an old laptop as an MP player The distribution of the operating systems in source form allowed me to easily write and add a device driver to support the PCL 724 I O card under FreeBSD and Mark Fos ter to patch NetBSD to provide audio and infrared support for the Shark A number of times I found myself going over the source code to verify elements that were not clearly documented documentation can not possibly cover everything Some early failed experiments for diskless booting the Shark were based on an old Linux platform by comparing the NFS implementation of the Linux version I was using with that of the Shark s NetBSD I quickly found out that the configuration would never work since the two were supporting different versions of the NFS protocol No less important were the various add on packages I used In some cases I experi mented with more than one package for a given task It was clear that the co existence and evolution of competing packages created evolutionary pressure that resulted in bet ter overall offerings A clear example of this case was the area of MP3 encoders and decoders The Shark with its StrongARM processor lacking floating point support is
10. which is defined by a start and an end time If you do not require a certain heating period you need to enter the same time of day as start and end time 4 Select the required day for the heating period 1 Monday 7 Sunday 5 Start of heating period 1 nominal operation 6 End of heating period 1 reduced operation 7 Start of heating period 2 nominal operation 8 End of heating period 2 reduced operation 9 Start of heating period 3 nominal operation 10 End of heating period 3 reduced operation Operating a Digital Answerer The state of this particular digital answerer 12 is indicated by a single messages indicator light Its behaviour is to be interpreted as follows 12 p 5 On Answerer is on and there are no messages Flashing Number of flashes indicates number of messages Off Answerer is off but there might still be messages Flashing rapidly Outgoing announcement is invalid or memory is full For remotely accessing the messages the device s owner is provided with a paper cut out remote access card that lists the eleven different commands five are to be used during message playback and six at all other times the answering machine supports Programming a PBX The low end PBX we examine 13 can be programmed from a dual tone multifrequency DTMF phone connected to the extension 21 only The PBX allows the specification of different extension ringing patterns for day and night use To specify
11. 9 February 2001 J Christopher Ramming editor USENIX Conference on Domain Specific Languages Santa Monica CA USA October 1997 Usenix Association Stephen C Johnson and Michael E Lesk Language development tools Bell System Technical Journal 56 6 2155 2176 July August 1987 T Berners Lee and D Connolly RFC 1866 Hypertext Markup Language 2 0 Novem ber 1995 J Bell F Bellegarde J Hook R B Kieburtz A Kotov J Lewis L McKinney D P Oliva T Sheard L Tong L Walton and T Zhou Software design for reliability and reuse a proof of concept demonstration In Conference on TRI Ada 94 pages 396 404 ACM ACM Press 1994 Larry Wall Tom Christiansen Randal L Schwartz and Stephen Potter Programming Perl O Reilly and Associates Sebastopol CA USA second edition 1996 Marc Eberhard Vgetty documentation center Online http alpha greenie net vgetty 1998 Current March 2002 Gert Doering Mgetty sendfax archive documentation centre Online http alpha greenie net mgetty 2002 Current March 2002 Jan Kasprzak Modem vgetty perl module Online http www cpan org authors id Y YE YENYA 1998 Current March 2002 Marcello Urbani dagrab Read audio tracks from a CD into wav sound files Online http web tiscalinet it marcellou dagrab html 2000 Current March 2002 Monty Cdparanoia an audio CD _ reading utility Online http www xiph org paranoia manual html 2002 Current
12. MP3 player Jeffrey Mogul kindly handled the tricky logistics for distributing the contest s Sharks and saved the day by explaining to me how a keyboard could be essential for its operation Eliza Fragkaki contributed the server s processing unit literally provided a helping hand during the CD ripping operation and patiently endured the prototype system s al pha and beta testing period Lorenzo Vicisano came up with the idea of using the Shark as an MP3 player while Isidoros Kouvelas and Vasilis Prevelakis offered encouragement help and interesting ideas during the prototype s implementation Finally Giorgos Gousios Konstantina Vassilopoulou and the anonymous referees provided valuable constructive comments and perti nent remarks on earlier drafts of this paper 21 Software Availability The source code for the PCL 724 device driver and the Shark MP3 player script is available at lt lt http www dmst aueb gr dds sw ifurnace gt References 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Diomidis Spinellis The information furnace User friendly home control In Proceedings of the 3rd International System Administration and Networking Conference SANE 2002 pages 145 174 Maastricht The Netherlands May 2002 Giorgos Lekakos Kostas Chorianopoulos and Diomidis Spinellis Information systems in the living room A case study of personalized interactive TV design In Proceeding
13. March 2002 Tord Jansson bladeenc MP3 encoder Online http bladeenc mp3 no 2002 Current March 2002 Conrad Sanderson Notlame LAME command line front end Online http hive me gu edu au not_lame 2002 Current March 2002 Michael Hipp mpg123 A fast MP3 player of Linux and Unix systems Online http www mpg123 de 2001 Current March 2002 Robert Leslie MAD MPEG audio decoder Online http www mars org home rob proj mpeg 2002 Current March 2002 30 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 Mark J Foster AV An audio visual equipment device driver for NetBSD Online ftp ftp talix com pub av 1999 Current March 2002 K Sollins RFC 1350 The TFTP protocol revision 2 July 1992 Sun Microsystems Inc RFC 1094 NFS Network File System Protocol specification March 1989 Christoph Bartelmus Pablo d Angelo Heinrich Langos Tom Wheely Karsten Scheibler Jim Paris Pawel T Jochym and Milan Pikula LIRC Linux infrared remote control Online http www lirc org 2002 Current March 2002 Markus Gutschke Gero Kuhlmann Jamie Honan Martin Renters Bruce Evans Rob de Bath and et al Etherboot open source code for creating boot ROMs Online http etherboot sourceforge net 2002 Current March 2002 Elizabeth Zwicky Simon Cooper and D Brent Chapman Building Internet Firewalls O Reilly and Associates Sebastop
14. The Information Furnace Consolidated Home Control Diomidis D Spinellis Department Management Science and Technology Athens University of Economics and Business Patision 76 GR 104 34 Athens Greece email dds aueb gr Abstract The Information Furnace is a basement installed PC type device that integrates existing consumer home control infotainment security and communication tech nologies to transparently provide accessible and value added services A modern home contains a large number of sophisticated devices and technologies Access to these devices is currently provided through a wide variety of disparate inter faces As a result end users face a bewildering array of confusing user interfaces access modes and affordances In addition as most devices function in isola tion important opportunities to exploit synergies between their functionalities are lost The information furnace distributes data provides services and controls an apartment s digital devices Emphasis is placed on accessibility and on exploiting the synergies that inevitably come up when these technologies and services are housed under a single roof The prototype implementation I outline integrates on a FreeBSD server the distribution of MP3 encoded music to DNARD NetBSD thin clients an answering machine a burglar alarm an Internet router a fax server a backup server and intelligent control of a PBX Keywords Home control automation multi modal int
15. ace attributes of the information furnace offer a potential roadmap for achieving these goals By implementing a prototype I discovered the pivotal role that open source software standards and the deployment process will play in such an endeavour Some may counter that my thesis for a centralised information furnace contradicts the proposed move from a complex general purpose personal computer towards user friendly simple and versatile information appliances 14 73 I can defend my po sition on two grounds Firstly the systems my proposed information furnace is set to 26 replace do not exhibit any of the information appliance design axioms simplicity ver satility pleasurability 14 p 67 Secondly my solution although based on personal computer technology does not entail at least in the form I designed it the two damn ing characteristics of PCs creeping featurism and an application oriented mindset 14 pp 80 87 I propose that application furnaces be individually configured by experts to match the needs to a home s occupants in the same sense as the house itself is archi tected In addition the information furnace I propose is in fact an information appliance albeit one with a rather large scope to integrate the home s control information and communication systems This integration aspect necessary to exploit the synergies I discussed is the diametrical opposite to the PC s one application for each task
16. arallel with dedicated hard ware providing redundancy or be isolated from it Elevators fire monitors and emer gency lighting should probably be left to work on their own tapping an elevator s call button or a fire alarm s output should be the limit to the type of coupling that should be considered safe Similarly control of mains voltages should be performed by ded icated hardware leaving to the information furnace the task of issuing the respective commands 20 4 3 Synergies The most effective user interface is the one that does not exist 28 14 29 Centralising all home control content and communications in a single place allows us to exploit syn ergies that make many control functions redundant or provide new and more versatile features In this sense the information furnace behaves as sentient computing system one that reacts to changes in its environment according to the user s preferences 23 The collocation of all services in a powerful processing and storage device makes it possible to provide centralised backup universal and multi modal access to all func tions and interfaces that are easy to use 12 Consider the alarm system motion detectors These can detect activity in rooms and can therefore be used to e start the running hot water circulation pump when an occupant approaches the bathroom or kitchen close the blinds when the owners are in a room to protect their privacy and oth erwise op
17. arch 2001 Roy Want and Gaetano Borriello Survey on information appliances Computers Graphics and Applications 20 3 24 31 May June 2000 Thomas Erickson Some prolems with the notion of context aware computing Communi cations of the ACM 45 2 102 104 February 2002 32
18. at hand Despite my earlier thoughts to the contrary I found that protecting a dial up connection can be worthwhile I do not have time to maintain the various MP3 players with the latest security patches and as the following excerpt from the information furnace s apache log shows dial up connections are actively scanned for security holes Tue Sep 18 20 35 49 2001 error client 195 158 192 25 File does not exist usr local www data scripts xcl x9c 20 winnt system32 cmd exe 6 Discussion In the previous section we saw that the concept of the information furnace is indeed realisable if only as a prototype with a subset of the functionality we prescribed in Sec tion 4 The move from distributed specialised appliances into a centralised information furnace is not without risks and potential problems Here I will describe the most im portant factors that facilitated and hampered the development as well as issues that are likely to affect the adoption and evolution of information furnace systems in the future A wider view of the challenges in deploying ubiquitous systems such as the one we describe can be found in 53 6 1 Open Source Software Clearly the most important aspect that affected the development was the availability of open source software The information furnace and its appendages were based on three different open source operating systems The stability and clear structure of FreeBSD provided the platform
19. ces can be used for putting the house to sleep and preparing it for its owners wakeup Other activities can trigger synergistic events As an example picking up the phone can cause the entertainment system to pause the music or video playback in the respec tive room when the alarm system detects an unlawful entry it can begin flashing all the house s lights to frighten the burglar and attract neighbourhood attention watering the garden should probably be avoided when the garden lighting indicates that a party is taking place a visitor overstaying his welcome might cause a gradual lowering of the house s temperature and lighting 5 Prototype Implementation To experiment with the ideas I outlined in the previous sections I designed and imple mented a prototype of the information furnace In all honesty this is not an entirely accurate description of the causal relationship between the two aspects of my work but seems to be the generally accepted politically correct way of expressing it The 13 ISDN line ISDN Terminal Adapter Motion Door and MP3 players PCs detectors window sensors Af POTS modem _ Ethernet hub Information Furnace Figure 3 Information furnace connection diagram GSM phone Door phone POTS phones Relay and sensor board Sirens implemented information furnace
20. chnologies such as Jini 61 can in the future be used to build the functionality of the information furnace out of preconfigured subsystems Other tech nologies that could influence the evolution of the information furnace concept include the use of indoor positioning technologies 62 to enhance the capabilities of the passive sensors we used and the adoption of the interactive digital TV as the front end for most leisure related interactions 63 6 4 User Interface A constant theme that came up during the development deployment and evaluation of the information furnace was its user interface The main objectives of the prototype 22 3 Communications Netscape _ 0 x Sees _ o x Eile Edit Yiew Go Communicator Help Eile Edit Yiew Go Communicator Help Communications Security Answering Machine Alarm Status Currently deactivated since Thu Oct 17 2002 23 50 Activate Exit wait period 5 minutes Store Entry wait period minutes Store Currently off since Thu Oct 17 2002 22 41 _ Activate Voice Messages Thu Oct 17 2002 22 13 01055512345 Play Delete Thu Oct 17 2002 22 36 John Smith Play Delete Delete all Fax Documents Sensor Log Date Time From hu Oct 17 2002 11 15 35 alarm trigger Stair3 disabled hu Oct 17 2002 11 15 36 alarm trigger Stair3 disabled hu Oct 17 2002 11 15 43 alarm trigger DiningRoom disabled hu Oct 17 2002 11 15 47 last message repeated 4 times
21. d with a normally closed tamper switch opening the device s cover or cutting its connecting wire will be immediately registered by the alarm unit The control unit is equipped with a battery which supplies power during a power failure In addition many outdoor sirens come with their own battery and are wired for stand alone operation if the power supplied by the control unit is interrupted or the siren s tamper switch is activated the siren will begin to sound Some systems are also installed with wall mounted panic buttons or similar signalling tokens that an individual can wear These are also useful when elderly or disabled people wish to signal they need attention Some owners also combine their unit with fire detection sensors however fire detection equipment installed to satisfy building regulations falls outside the scope of this article Related to security are also the door phone and sometimes a TV camera the asso ciated door opener and the remote controlled garage door opener Note that the typical door phone and opener combination is an system cunningly designed to minimise the number of individual cables required for its installation Interfacing with such a system can be very difficult however many small private branch exchanges PBXs offer a door phone door opening option and can be easier to interface 2 4 Communication The modern home s communication needs are served by the phone and an Internet con nection u
22. ected location it can be accessed from all networked locations Thus elements such as the family s music and photograph collection the answering machine messages lighting controls the bur glar alarm log and the heater programme are available from all rooms in the house and also from remote locations Naturally the centralisation of these important functions entails considerable risks these can however be effectively controlled if the associated policies are centralised reviewable and implemented under a reasonably secure operat ing system In addition all the programming and other information stored in the device can be centrally backed up on a regular basis Surprisingly the information furnace concept when applied as a replacement for the stand alone provision of the functions it supports increases all aspects of the figure of merit M originally proposed for nomadic computers 24 7 Intelligence Size x Cost x Power However the most important benefit of the centralisation is the synergies that can be exploited we will examine this aspect in Section 4 3 The final element of the information furnace architecture concerns its user interface I do not believe that a single user interface is appropriate for all occasions For this reason the information furnace offers a number of different access modes These can include web forms and Java applets telephone based DTMF commands infrared re mote controls access via Bluetooth de
23. ementing a sentient computing system Computer 34 8 50 56 August 2001 Tsugio Makimoto Kazuhiko Eguchi and Mitsugu Yoneyama The cooler the beter New directions in the nomadic age Computer 34 4 38 42 April 2001 Gordon Bell A personal digital store Communications of the ACM 44 1 86 91 Decem ber 2001 Gordon Bell and Jim Gray Digital immortality Communications of the ACM 44 3 28 30 March 2001 Gordon Bell and Jim Gemmell A call for the home media network Communications of the ACM 45 7 71 75 July 2002 Mark Weiser The computer of the 21st century Scientific American 265 3 66 75 September 1991 Roy Want Trevor Pering Gaetano Borriello and Keith I Farkas Disappearing hardware IEEE Pervasive Computing 1 1 36 47 January March 2002 Diomidis Spinellis and V Guruprasad Lightweight languages as software engineering tools In Ramming 33 pages 67 76 29 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 Diomidis Spinellis Reliable software implementation using domain specific languages In G I Schu ller and P Kafka editors Proceedings ESREL 99 The Tenth European Con ference on Safety and Reliability pages 627 631 Munich Garching Germany September 1999 ESRA VDI TUM A A Balkema Diomidis Spinellis Notable design patterns for domain specific languages Journal of Systems and Software 56 1 91 9
24. en them in cold summer nights and sunny winter days to improve the home s climate control e turn artificial lighting on and off as the owners move across rooms additional hints such as entertainment system or communications activity can be used to improve the heuristics of this approach avoid ringing the phone in a bedroom with no activity where presumably an occupant might be sleeping when activity in another room indicates that someone else might prefer to pick up the phone Note that reversing the above conditions does not yield a heuristic many adults would agree with When leaving the home and on return the activities we perform can be compa rable to walking through a jet pilot s checklist The information furnace can collec tively perform these standardised activities through a single command Thus the leave home command will turn on the answering machine switch off the internal artificial lighting and entertainment systems lower the central heating temperature light the en trance activate the burglar alarm and open the garage door On return a single pass word protected command will deactivate the burglar alarm turn off the answering ma chine play back any incoming messages provide caller id information on unanswered phone calls switch on the internal artificial lighting and entertainment systems raise the central heating temperature switch off the entrance light and close the garage door Similar sequen
25. erfaces Personal and Ubiquitous Computing 7 1 53 69 2003 This is a machine readable rendering of a working paper draft that led to a publication The publica tion should always be cited in preference to this draft using the reference in the previous footnote This material is presented to ensure timely dissemination of scholarly and technical work Copyright and all rights therein are retained by authors or by other copyright holders All persons copying this information are expected to adhere to the terms and constraints invoked by each author s copyright In most cases these works may not be reposted without the explicit permission of the copyright holder 1 Introduction Although our complex lives are not necessarily improved by each new technological widget we adopt uncooperative devices and appliances with deficient user interfaces can certainly conspire to frustrate us Over the past three years I have experimented with a number of technologies that gave birth to the information furnace concept a basement installed PC type device that integrates existing consumer home control in fotainment security and communication technologies to transparently provide ubiq uitous access and synergistic value added services In the following sections we will examine the devices and appliances lurking in the modern home overview the prob lems associated with the current breed of devices and go over the basic elements of the information furnace c
26. ering programs apart from the one you really require that is can be directly fitted into a watering hose or can control multiple valves and can receive additional feedback from a soil humidity sensor 2 2 Infotainment The array of devices used for servicing our entertainment and supposedly our infor mation access needs covering the so called infotainment category is bewildering It involves CD MP3 and DVD players radios the increasingly digital and interactive 2 television tape or hard disk based video recorders digital photograph and video cameras game consoles and networked personal computers Across those devices we typically witness a gratuitous duplication of functionality and a lack of standardisa tion both are exemplified by the growing array of remote controls adorning the typical lounge table The last problem has spurned research 3 and development of universal configurable remote controls 2 3 Security Home owners not wishing to trust their security of the prized possessions I outlined in the previous paragraph to the watchful eye of the local cop or a bona fide man eating animal often end up contributing to the bottom line of the burglar alarm and home monitoring industry A modern burglar alarm consists of a control unit an array of sensors and facilities for alerting whomsoever the owner can afford The sensors used include motion detectors based on passive infrared PIR microwave or hybrid tec
27. es using communication channels tailored to their 24 preferred interaction methods 68 The information furnace s computational power and flexibility in configuring input and output peripherals make it an ideal platform for deploying the appropriate interfaces Large fonts voice and haptic interfaces eye gaze control and speech recognition are some of the technologies that could allow users with disabilities participate in a richer interaction with their home environment 6 6 Security and Dependability Before information furnaces are widely deployed an important new risk that will have to be addressed is the pervasive impact of security breaches and software or hardware failures Currently a guessed answering machine PIN will only provide access to the owner s voice mail messages in contrast a compromised information furnace will allow the intruder to control many of the home s appliances On the other hand the increased computational power of the information furnace enables the deployment of more so phisticated authentication mechanisms based e g on one time passwords or on private keys stored on a mobile phone s subscriber identity module SIM card Dependability issues are equally important The integration of existing consumer home control infotainment security and communication technologies on the informa tion furnace platform creates a single point of failure a non functioning information fur nace will result in cons
28. g track but will not remember to skip the same track in the future On another front a burglar alarm unit could provide a precise report of the alarm triggering circumstances and allow its user to remotely probe and disable individual sensors Finally the PBX we examined could be more versatile if it supported different day and night mode start times for different days of the week A general lack of functionality witnessed in all the devices we examined is a facility to backup and restore the tediously entered program data True many devices have a power backup system for their memory contents but in my experience that inevitably one day will fail typically long after the user has forgotten how to program the device and has lost the respective user manual 3 3 Lost Synergies I will fully expand the synergies made possible when all home systems communicate and cooperate with each other in Section 4 3 at this point I will illustrate my thesis with a simple example The blinking clock syndrome refers to the myriads of device clocks flashing 12 00 all over our planet Even in households where these are cor rectly set after a power failure twice a year they need to be re adjusted following the daylight savings time settings However a correct time signal enters a modern home from at least three different sources teletext TV the radio data system RDS and the Internet 16 In addition modern operating systems can correctly in
29. he Digital Network Appliance Reference Design DNARD left and the Shark as an MP3 player right 521 10297 vol music Classical Bach FrenchSuites cdl track01 mp3 10298 vol music Classical Bach FrenchSuites cdl track02 mp3 10299 vol music Classical Bach FrenchSuites cdl track03 mp3 This format allows simple sed scripts to select data based on a CD or track identi fication number and feed the results directly as a playlist to MP3 players such as mpg123 45 and mad 46 The first MP3 player connected to the information furnace was a network com puter In 1997 Digital Equipment Corp which became part of Compaq Computer Corp which became part of HP produced the DIGITAL Network Appliance Reference Design DNARD and published the hardware specifications for free use DEC used the code name Shark to refer to these NCs probably due to the plastic fins used to make them stand in an upright position Figure 7 The DNARD exploits the power of the StrongARM microprocessor combined with the flexibility and economy of industry standard busses and chips With the sale of Digital Semiconductor to Intel in early 1998 ownership of the StrongARM passed to Intel Since that time the DNARD design has no longer been supported by Digital or Compaq Using however a DNARD as an MP3 player connected to the information furnace was an attractive proposition because of the DNARD s attractive slim desig
30. hnologies magnetic contacts that detect the opening of doors and windows and glass vibration sensors Sensors placed under mats and carpets and light beam detectors are less often used Contrary to the popular perception promoted by Hollywood films visible red intersecting laser beams used to test a burglar s agility are not a popular sensor option The control unit is typically an overpriced and underpowered microprocessor con trolled contraption It monitors the sensors due to a dearth of input ports these are often or wired into zones allows the owners to activate and deactivate it using a PIN distinguishes between a normal entry e g through a door that provides a delay for deactivating the system and an unexpected event e g motion entry through a window that immediately triggers an alarm offers a facility for operating with the occupants inside the house night mode and controls the alarm triggering and rearming process Alarms in most cases sound an internal siren that is supposed to frighten the burglars but will in most cases only frighten the poor owners when set off in a night mode operation activate an external siren often coupled with a strobe light that passers by typically try to ignore and notify via a modem or a recorded message a control centre or a list of pre assigned phone numbers The whole system has some redundancy and self monitoring capabilities Many sensors and sirens are equippe
31. iderable inconvenience to the home s residents A three pronged approach will be needed to provide a dependable platform First of all the information furnace shall be based on reliable hardware and software configurations Our proto type system based on vintage IBM hardware and the stable version of the FreeBSD operating system achieved continuous operation exceeding 200 days In addition the information furnace and the devices it controls must be designed so that hardware and software problems result in a fail safe graceful degradation of the provided services As an example a catastrophic motherboard failure could result in doors reverting into manual control and phone service provided only on a single handset In the longer term approaches such as autonomic computing 69 may result in systems with substantially improved dependability and serviceability characteristics 6 7 Deployment and Maintenance Related to the issue of dependability and perhaps the biggest roadblock to the univer sal deployment of information furnaces is their installation testing and maintenance The broadband deployment business plans of a number of telecommunications compa nies were foiled by the cost incurred for having expensively trained technicians install the network adapters at the each customer s premises 70 The installation of an in formation furnace using today s interfacing technologies will probably be an order of magnitude more challe
32. ill ensue 6 8 Lifespan Mismatch The mismatch between the lifespan of residential housing and that of typical IT con sumer appliances is one other source of concern Most dwellings are designed to last for fifty or more years In contrast historical experience suggests that typical IT appli ances are outdated in less than two years are impossible to service using spare parts after ten years and in thirty years even the skill set required for their maintenance dis appears from the job market Performing a hardware and software upgrade every five years current practice for workstation maintenance in many IT departments will most probably not be a proposition home owners are likely to accept Standardising hardware interfaces and home configuration files may initially appear to be a solution until one considers the difficulty one would face today in reading data from a standardised and once ubiquitous 9 track half inch tape Solutions for matching the life of the infor mation furnace to that of the home it supports are likely to be provided either through the application of research results from the area of digital preservation 72 or from a specialised industry segment supplying IT appliances with guaranteed support through a of a very long lifespan 7 Concluding Remarks There is tremendous scope for making the devices found in a modern home more easy to use and synergistic The isolated location all inclusive scope and multi modal interf
33. n silent operation it does not contain a disk or a 19 fan infrared port and audio hardware The Shark runs NetBSD 1 5 patched with Mark Foster s AV package to support the audio hardware and the infrared port 47 The Shark gets its initial configuration from the information furnace dhcpd amp server and boots us ing the trivial file transfer protocol TFTP 48 it subsequently mounts its file systems and the MP3 disk volume over the network file system NFS 49 A small shell script run at startup time allows us to use a remote control to select music The irw command from the LIRC distribution 50 reads remote control messages These can be a number forming a CD track or music type code play stop previous next or pause The play command starts an MP3 player process All other commands are handled by sending signals to the MP3 player process stop kills the player process pause pauses it previ ous and next send it the USR1 and USR2 signals respectively Playlists are generated by a sed 1 command that prints the master playlist from the music part selected until its end As music is sorted and traversed according to its content when the player finishes the selected track or CD it will continue playing roughly similar content Shuffling of music tracks is simply accomplished using the NetBSD shuffle command The two other MP3 players we deployed use similar concepts but run on less pol ished hardware and software config
34. ne drier and coffee machine 5 Unfortunately for this article s au thor and probably fortunately for their other users none of these devices offers a viable interface for controlling their operation 3 Modern Problems The coexistence of the devices and systems I described in the previous section under the same roof is a sad story of unattained potential lost opportunities and waste 3 1 User Interface The most important problem inflicting the systems is their often dysfunctional to put it politely user interface The reason behind this problem stems from the restricted human interaction devices the systems have at their disposal In most cases interaction devices consist of small numerical liquid crystal displays LCDs sometimes capable of displaying some additional hieroglyphic symbols and a few domain specific buttons The usability aspects of consumer electronic products 6 and even their design prin ciples 7 differ from those of workstation based software However given the increas ing similarities and interactions between products in the two categories it is instructive Figure 1 A heating controller and its programming interface to examine the usability of home appliances through accepted user interface design prin ciples The appliances I described rarely follow the principles of a user centred design 8 p 188 It is thus difficult to determine what actions are possible at any moment the system
35. nging The interactions of multiple systems can result in many subtle and difficult to find bugs Some of them can be amusing the first visitors to ring the doorbell after the information furnace was deployed were greeted with a telephone answering machine message More than a year after the furnace s deployment we are still tuning its operation and correcting minor by now inconveniences 25 Most people would not regard the existence of a resident system administrator an acceptable solution to this problem The availability of stable software rather than its organic home growth the adoption of the domain specific languages we saw in Sec tion 5 2 and the initial configuration of the furnace by a qualified professional can help in this direction However the above process although similar to other processes followed for building homes is completely different from the ad hoc procedure typ ically employed when purchasing and deploying consumer oriented hardware plug it in play with the buttons avoid reading the manual Although standard interfaces sim ilar to those that currently allow the seamless installation of USB style peripherals on PCs may somehow ease the configuration burden the current state of the art makes even the installation of home theatre equipment a formidable task 71 Unless the widespread deployment of information furnaces is coupled with an appropriate installa tion and maintenance process significant problems w
36. notification func tions of the information furnace are handled by software written on top of the vgetty 38 extension a voice handling add on to the mgetty 39 package which in turn replaces the Unix getty S terminal handler to handle data and fax calls I wrote the incoming and outgoing modem interaction scripts in Perl using the Modem Vgetty 3 40 Perl package 16 leave set_sensor_active ALL OFF set_sensor_active Door ACTIVE gt wait_for_door_open A wait_for_door_open syslog LOG_INFO Waiting for door open ActiveSensor gt door_open r door_open syslog LOG_INFO Door opened 10s gt day arm A Figure 5 DSL specification of the leave command The PBX provides a global 100 phone quick access memory feature By using these memories one can access the same number from all extensions without having to indi vidually program and maintain the memories of each different telephone Apart from offering a centralised point for storing the quick dial numbers this approach obviates the need to handle the disparate user interface each device has for storing phone num bers is the programming sequence code AUTO number store or MEM code number hangup Of course this approach solves one user interface problem by replacing it with another since the quick access programming sequence for the PBX is hold your breath 6206206 00codeOnumber 6206
37. nuously running it through the house In my experience modern heating controllers do not deal with this complication The natural light entering a building is often controlled through external blinds or stores These also play an important role in regulating the heat flowing into or out of the building In addition a heliostat device can be used to track the sun movement and actively reflect sunlight into the building Artificial lighting can be electronically con trolled through a system such as X10 or LonWorks in the United States and the European Installation Bus EIB in Europe Perversely in the case of the EIB at least it is cur rently cheaper to control lights using 230V switches and individual switch to appliance power carrying cables than to use a signal and power bus cheaper control switches and the associated electronics This is clearly a case where the silicon economy has not yet done its work Other interesting elements of modern artificial lighting include light fixtures with integrated motion and light detectors that are increasingly used outside homes as burglar deterrents time switches used for the same purpose inside the house and economy type light bulbs that may take up to five minutes to reach their rated light output A case where the silicon economy has worked is exemplified by the availability of affordable devices to control plant and garden watering These often sport a bewildering array of daily and weekly wat
38. o would adopting TCP IP for communicating with all devices 55 On the other hand the standards and the resulting economies of PC manufacturing coupled with the rapid obsolescence of PCs provided me with a number of cheap and viable platforms for deploying the information furnace s infrastructure While scaveng ing obsolete hardware can be a viable strategy for a researcher or a hobbyist it can not form a long term technology adoption plan However the above forces can also result in the development of affordable hardware platforms based on established components and processors like the DNARD Shark These platforms based on cheap industry standard busses and chips can form the base of the future s mass produced information furnaces 6 3 Emerging Technologies Several new technologies are likely to influence the way the information furnace con cept is realised in practice Closer networking of appliances is likely to influence the way information furnace architectures are deployed and interfaced Third generation mobile phones 56 and personal area networks using Bluetooth 57 may provide the infrastructure for users to communicate with the furnace on the road and at home while wireless LAN technologies such as IEEE 802 11b HiperLAN and HomeRF 58 may be used for interfacing the information furnace with the devices it controls On the software side components 59 architectures based on web services 60 or adaptive network centric te
39. ol CA USA second edition 2000 Nigel Davies and Hans Werner Gellersen Beyond prototypes Challenges in deploying ubiquitous systems IEEE Pervasive Computing 1 1 26 35 January March 2002 Markus Lauff and Hans Werner Gellersen Adapation in a ubiquitous computing man agement architecture In Proceedings of the 2000 ACM symposium on Applied computing 2000 pages 566 567 ACM Press 2000 Robert E Filman Editor s introduction Embedded internet systems come home IEEE Internet Computing 5 1 52 53 January February 2001 Lee Garber Will 3G really be the next big wireless technology Computer 35 1 26 32 January 2002 Pravin Bhagwat Bluetooth Technology for short range wireless apps Internet Comput ing 5 3 96 103 2001 Linda Dailey Paulson Exploring the wireless LANscape Computer 33 10 12 16 Octo ber 2000 Clemens Szyperski Component Software Behind Object Oriented Programming Addison Wesley 1998 Michael Stal Web services Beyoond component based computing Communications of the ACM 45 10 71 76 October 2002 Ken Arnold editor Jim Waldo and the Jini Technology Team The Jini Specifications Addison Wesley second edition 2000 Ioannis Mathes Adamantia Pateli Argiris Tsamakos and Diomidis Spinellis Context aware services in an exhibition environment the mEXPRESS approach In Proceedings of the eBusiness and eWork Conference Prague The Czech Republic October 2002 31 63
40. oncept and its prototype implementation Further implementation details on technologies behind the system we describe can be found in 1 this paper focuses on the system s concept architecture and evaluation 2 The Modern Home A modern home contains a large number of sophisticated devices and technologies Current and near future technologies and respective devices can be roughly categorised into the categories of home control infotainment security communication and special purpose devices 2 1 Home Control Contemporary central heating systems are regulated by one external and a number of internal temperature sensors in conjunction with a control unit occupants use to set the desired room temperature The system compares the internal room temperature to the setting of the control unit and using the external temperature as a compensating factor regulates the temperature of the water produced by the local heat generating plant or the valve bringing remotely heated water into the home Burners often have their own control circuits based on target temperatures for the burner and the circulating pump but we can regard them as a black box for the purposes of this article Convenience ele ments associated with control units involve the ability to maintain different temperature settings for day and night manually set the system to day night or absence mode keep a weekly schedule of automatic switchovers between these modes and switch off
41. ove actions and also informs us on any pending voice and fax messages or missed calls Although this interface operating on voice prompts and DTMF commands does not utilise a fancy graphical user interface GUD it has literally halved the twice a day appliance interactions we would have to engage in 6 5 Human Diversity Coupled with the information furnace s new capabilities comes a vast array of tuning and parameterisation possibilities The appropriate methods and possibly interfaces for configuring these are an open question Environments that automatically adapt to their users preferences and agent based architectures that handle tasks on behalf of users have been touted as a possible answer 65 66 In practice however users have often found such environments complex intrusive and unpredictable some researchers be lieve that being in control gaining mastery of a system and accepting responsibility for its actions will lead to feelings of accomplishment that should not be overlooked 67 In addition population variation in technical sophistication cognitive and perceptual abil ities and cultural background will result in users with radically different expectations from their interactions with the information furnace Orthogonal to the above variations in interaction style are the needs of users with disabilities children and the elderly To those the information furnace can provide universal access to all home s applianc
42. provides the functionalities of an alarm system an answering machine a fax server a PBX interface an internet firewall and router a content management and distribution point and a backup server 5 1 System Structure You can see a diagram of the information furnace connections in Figure 3 The infor mation furnace consists of a low end 100 MHz Pentium PC equipped with a 80Gb hard disk an additional serial port card and an Advantech PCL 724 24 bit digital input output card For the PC I was fortunate to acquire a surplus IBM Personal Computer 340 unit running FreeBSD 4 1 and later 4 6 it proved to be a very stable platform with uptimes in excess of 200 days The national telecom operator provides with each ISDN connection a terminal adapter with two POTS plain old telephone system traditional analogue phone interfaces and an RS 232 or USB data port The data port is connected to the information furnace for providing internet access and firewall functionality The two POTS interfaces are connected to an entry level analogue PBX I decided to use an analogue PBX instead of an ISDN model to minimise the system s cost and by rea soning that new upcoming telephony offerings such as xDSL or fixed wireless lines might not be compatible with an ISDN PBX The PBX connects to a number of plain phones a door entry phone a relay actuator for opening the door and a POTS modem used for programming the PBX and providing a voice DTMF interface
43. rforming the functions of a firewall a router an intercom and a PBX 11 INPUT CONTROL artificial lighting pno alg heating web E STORAGE COMMUNICATION air conditioning Java app ols music collection firewall nes Bluetooth devices hot water provision PDA contents router remote controls external internal blinds photographs intercom plant watering temperature sensors video collection PBX motion detectors alarm sirens door openers opening sensors rain moisture sensors Information Furnace Figure 2 Information furnace functionality acting as the hub of a Home Media Network 27 I take this maximalistic view be cause by my experience every system and function moving to the information furnace automatically benefits from universal multi modal access easy to use control and data backup while providing additional opportunities for synergies with other services When some type of functionality can not be directly implemented by the hardware at hand the information furnace shall at least communicate with the respective dedicated device so that it can indirectly control it As an example by communicating with a PBX using a simple modem one can provide a decent user interface to the functionality I described in Section 3 1 All integration shall of course be performed with an eye on safety and security Where appropriate the information furnace should work in p
44. roviding delays automatic re arming and notification intervals Different levels of logging are provided by calls to the Unix syslogd amp daemon Apart from triggering the various sirens alarms cause the queuing of voice and data messages to kind unlucky individuals and the responsible authorities via the modem and the backup GSM phone 15 The actual behaviour of the alarm is specified using a domain specific language 30 31 32 A domain specific language DSL 33 is a programming language tailored specifically for an application domain rather than being general purpose it captures precisely the domain s semantics Examples of DSLs include lex and yacc 34 used for program lexical analysis and parsing HTML 35 used for document mark up and VHDL used for electronic hardware descriptions Domain specific languages allow the concise description of an application s logic reducing the semantic distance between the problem and the program 36 30 As a design choice for implementing safety critical software systems DSLs present two distinct advantages over a hard coded program logic Concrete Expression of Domain Knowledge Domain specific functionality is not co ded into the system or stored in an arcane file format it is captured in a concrete human readable form Programs expressed in the DSL can be scrutinised split combined shared published put under release control printed commented and even be automaticall
45. s In Figure 8 you can see a simple prototype demonstrating how an interface to the information furnace s communications and security functions can be provided through simple web forms Similar forms could be offered in the future through a mobile phone s or PDA s web browser providing a consistent interface to the residents at home and on the road In addition research in the area of multi platform service delivery 64 and create once publish everywhere COPE strategies could in the future provide the infrastructure for offering a consistent personalised interface across multiple devices with different affor dances Future research could be directed towards examining the use of the proposed prototype in its context of application Scholars could then consider issues arising from the application of human computer interaction theories into its different application do mains However the most important qualitative change the information furnace brought to the user interface was a move from the typical imperative commands humans issue to their appliances turn answering machine on deactivate alarm mute the volume into more a sophisticated declarative dialogue Thus typical commands that we issue are we are leaving home which activates both the alarm and the answering machine once the building s door is opened and also unlocks the street door and a complemen tary we are back now which reverses the ab
46. s of the 9th European Conference on Information Systems Bled Slovenia June 2001 Diomidis Spinellis Palmtop programmable appliance controls Personal Technologies Personal and Ubiquitous Computing 2 1 11 17 March 1998 Amitava Dutta Roy Networks for homes IEEE Spectrum 36 12 26 33 December 1999 Fotis Georgatos and Annie Pinder Coffee HOWTO Online http www linuxdoc org HOWTO mini Coffee html 2000 Current March 2002 Sung H Han Myung Hwan Yun Jiyoung Kwahk and Sang W Hong Usability of con sumer electronic products Industrial Ergonomics 28 143 151 2001 B A T Brown and M Perry Why don t telephones have off switches Understanding the use of everyday technologies Interacting with Computers 12 623 634 2000 Donald A Norman The Psychology of Everyday Things BasicBooks New York NY USA 1988 Ben Shneiderman Designing the User Interface Strategies for Effective Human Computer Interaction Addison Wesley third edition 1998 Jef Raskin The Humane Interface New Directions for Designing Interactive Systems Addison Wesley 2000 Siemens Building Technologies Room Units for Use with Heating Controllers QAW70 June 1999 Document code CE2N1637E Thomson Consumer Electronics Indanapolis USA GE Digital Answerer 1996 Docu ment code 2 9865 Matsushita Electric Industrial Co Osaka Japan Panasonic Electronic Modula Switch System Modem KX T206 Installation Manual 1993 Documen
47. sing the plain old telephone system POTS and a modem the integrated services digital network ISDN and a terminal adaptor or another digital network tech nology e g a digital subscriber line DSL and the associated terminator box Sharing of phone lines and internal communication can be facilitated via a PBX while the cor responding sharing of data connections can be facilitated by a network and hub or wireless network and a router PCs are also increasingly used to share network collec tions Phone lines are often terminated on an answering machine and a fax the more exotic ISDN offerings trumpeted by the incumbent telecom providers videophones digital faxes have been persistently snubbed by consumers Connected to the data lines are PCs holding valuable personal data and in dire need of regularly scheduled back ups and connected to the PC are various personal digital assistants PDAs holding the owner s telephone number directory and other personal data A baby monitor typically functions independently of the above setup A variety of wired and wireless home net working technologies aim at interconnecting the systems I described 4 2 5 Special purpose Devices Finally inside a modern home there is a number of electronically controlled special purpose devices These include the humble vacuum cleaner the microprocessor en gineer show off case microwave oven and the increasingly clever refrigerator oven washing machi
48. structure and creates a metadata file foreach CD info txt by pulling information out of the cddb com and later the freedb org server I decided to store the metadata into a separate file and not use the ID3 standard because the type of data available from the public CD directories does not exactly match that maintained in the MP3 ID3 structures A separate Perl script crawls the content directories gath ering metadata and creating the content directory in plain text HTML and LaTeX file formats Each CD is identified by a three digit number and each individual track is iden tified by a five digit number Figure 6 These numbers are again stored in one plain text file index txt for each CD The numbers increase monotonically as new CDs are added and are never reused thus providing numbering persistency so that bookmarks and music collections are not rendered invalid when CDs are added or deleted The CD and track identification numbers are also needed for selecting a particular CD or track using a simple remote control I reserved two digit numbers for creating bookmarks to particular songs and single digit numbers for identifying a music type e g Rock Jazz or Classical from which an MP3 player would randomly shuffle tracks The last option proved to be the most popular The plain text file forms the track database It simply contains track and CD identification numbers as comments followed by the respective file name 18 Figure 7 T
49. t code PSQX1158YA KW0796KM1027 Donald A Norman The Invisible Computer MIT Press Cambridge MA USA 1998 28 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Catherine Plaisant and Ben Shneiderman ON OFF home control devices Design is sues and usability evaluation of four touchscreen interfaces Interacting with Computers 3 1 9 26 1992 David L Mills RFC 1305 Network time protocol version 3 specification implementa tion March 1992 M Weiser Some computer science issues in ubiquitous computing Communications of the ACM 36 7 74 84 October 1993 Larry Press Personal computing the post PC era Communications of the ACM 42 10 21 24 October 1999 Elizabeth Mynatt Douglas Blattner Meera M Blattner Blair MacIntyre and Jennifer Mankoff Augmenting home and office environments In Proceedings of the third interna tional ACM conference on Assistive technologies pages 169 172 ACM Press 1998 Stewart Benedict X automate Linux Journal 1999 57es 7 1999 Goran Devic Home entertainment linux MP3 player Linux Journal 2000 71es 8 2000 Armando Fox Brad Johanson Pat Nanrahan and Terry Winograd Integrating information appliances in an interactive workspace Computers Graphics and Applications 20 3 54 65 May June 2000 Mike Addlesee Rupert Curwen Steve Hodges Joe Newman Pete Steggles Andy Ward and Andy Hopper Impl
50. tally unsound Space Finally many devices occupy space in living areas daily imposing their unsightly pres ence on us The ubiquitous table with the telephone answering machine and fax is one example the collection of the remote controls on the lounge table is another 4 The Information Furnace The Information Furnace supporting the post PC ubiquitous computing paradigm 17 18 is a basement installed PC type device that integrates existing consumer home control infotainment security and communication technologies to transparently pro vide ubiquitous access and synergistic value added services The use of integrated in telligent devices in the home automation area is not a new concept 19 20 21 22 23 the information furnace differs however from other approaches by prescribing concrete architectural guidelines expressly adopting a maximalistic approach towards its func tionality and aggressively targeting and exploiting the resulting synergies 4 1 Architecture The architecture of the information furnace is based on three basic premises The device 1 is located in the basement or in a cupboard 2 acts as a central hub for content communications and control and 3 offers multi modal ubiquitous and easy to use access to all its functions The location of the device in a secure non accessible place is central to our design having a number of important repercussions Firstly the same location will be used to termina
51. te the various connections These often include home networks telephone lines reception antennas network lines and cable TV connections The unsightly presence of all these cables can only be accommodated in a specially provisioned place In addi tion the noise the system will generate can be effectively isolated Rotating hardware hard disks and fans and other noise generating components such as electromagnetic relays can be brought together into a single place keeping the rest of the house serene Furthermore the system can be physically secured deterring burglars minors or even pranksters have you checked your answering machine message lately Finally an ap propriate uninterruptible power supply UPS can be provisioned to constantly maintain power without worrying about its size noise or appearance or the distribution of power to multiple locations As the furnace acts as acentral hub for content communications and control we can eliminate wasteful duplication provide universal access to all its functionality from any local or remote location centralise our access and control policies effectively backup all data and most importantly exploit the synergies that the centralisation allows A single modern CPU can easily handle all the functions I described in Section 2 Thus 10 the numerous underpowered specialised devices can be replaced with a single general purpose one When all functionality is housed in a centrally conn
52. terpret and adjust the time following the local daylight savings rules Our wonderful devices however fail to cooperate to correctly set their time Even modern sophisticated cooking ovens whose marketing literature implies that they possesses artificial intelligence are unable to set their clock to the correct time 3 4 Provisioning Related to the lost synergies is the duplication of hardware and functionality we witness in the modern home Provisioning communication user access power and space for all different devices is simply an unproductive use of resources Communication The systems I outlined in Section 2 are typically implemented using the following dis tinct communication networks 1 Voice 2 Data 3 Door interfacing 4 Heating 5 Security 6 Light control There are expensive systems that integrate some of the above functions but the general case involves a waste of resources Usability Concerns Each home system has its own user interface with its ergonomically challenged human interfacing devices Humans have to learn different dysfunctional interfaces to perform a limited number of tasks Power Each system needs line power and in the best case also has a separate backup power system typically a 9V battery Apart from the nuisance of maintaining the tens of dif ferent backup power systems the power requirements of all devices add up to a sizable power drain which is both expensive and environmen
53. the day or night starting time the following procedure has to be followed 13 p 25 7 To enter the system programming mode dial 6206206 e To set the day night switching time dial 71 A BB CC D where Ais to specify the day start time to the specify the night start time BB is the hour 01 12 CC is the minute 00 59 D is 0 for AM and 1 for PM e To exit the system programming mode dial 6206 The examples we have seen illustrate that in many cases the user interface of consumer oriented home appliances and control devices is far from ideal Clearly hu man interface studies and approaches towards better interaction paradigms 14 15 have not yet found their way into widespread practice 3 2 Lacking Functionality One other problem with the devices we examined is that for a number of reasons they may impose arbitrary limits on their functionality or lack support for useful functions For many devices the available CPU power RAM or ROM are just not sufficient for implementing a given function For others the already complicated user interface would crumble under the requirements of the added functionality As an example there is no reason why the heating controller I described should support only three heating periods per day or not allow one to provide a schedule for the temperature of the running hot water as well as the temperature of the room Similarly a CD player may offer a facility to skip a borin
54. u Neipai 12321 Paschalies Mesa Pao Ti Nekri Gi 1 42227 oncerti Grossi CD 1 578 CD 2 579 La Folia And Other Sonatas 978 Dvorak Cello Concerto Scherzo Capriccioso 580 Symphony 7 Slavonic Dances 584 Symphony 8 Slavonic Dances 582 Symphony 9 From The New World Carnaval Overture 583 Gershwin Cuban Overture Second Rhapsody Song Book 6 Melodies 3 Preludes 58 Gorecki Symphony 3 Sorrowful Songs 585 et D Document Done Document Done Figure 6 CD and track level HTML playlists 5 4 Content Distribution A motivating requirement that led to the information furnace s conception was the abil ity to access our music collection from any networked place in the house Converting CDs into a collection of MP3 compressed files is a relatively easy task these days I used dagrab 41 and cdparanoia 42 to extract raw content from audio CDs and the encoders bladeenc 43 and notlame 44 to convert that content into MP3 form More difficult were the tasks of organising the transfer of a set of CDs into MP3 format the so called ripping operation systematising the material s storage and access provid ing useful metadata and setting up an appropriate content directory The ripped CD directories form a hierarchical structure made up out of the music type the composer performer or band name the album name and the CD number A script crawls the directory
55. urations One consists of an Intel 1OOMHz Pentium PC that boots a copy of FreeBSD diskless from the information furnace using etherboot 51 the other is an old laptop running SuSE Linux 7 0 Having the information fur nace utilise simple standards for organising and disseminating the content a text index and MP3 files exported via NFS as a directory tree allowed me to choose the operating systems opportunistically I selected FreeBSD to avoid the burden of configuring main taining and provisioning disk space for another operating system the player shares the read only partitions of the information furnace and SuSE Linux because it was the first OS installation to run correctly on the laptop s idiosyncratic hardware 5 5 Security and Availability The information furnace is secured in a place that is not easily accessible continuously performing a number of critical functions For these reasons it is imperative that it runs unattended and recovers gracefully after any problem An appropriately provisioned and correctly configured UPS proved to be essential for its reliable operation The information furnace also acts as an internet router and as a firewall by means of the native FreeBSD user mode ppp amp package running with network address trans lation NAT enabled This approach while not perfect is adequate for the profile of the users living inside the firewall Configuring the filters was relatively easy once I had reference 52
56. vices or even a command line interface Thus for selecting a song to hear one will use an infrared remote control to start the hot water boiler when returning from a trip one will issue DTMF commands over the cellular phone to open the garage door one could use a Bluetooth interface of a PDA and to program or review the activity log of the PBX or the burglar alarm one would prefer to interact with a web form Ideally all functionality should be available from all devices at night one might prefer to use the bedside phone to check the burglar alarm sensors when working on a PC a web interface might be used to review the answering machine messages Some of the access modes can be more easy to use than others however the processing and storage power of the information service means that there will be no artificial restrictions to the usability of a particular access mode As an example a complete answering machine help menu can be made available as a voice message over a phone connection without requiring the user to rely on cut out cards or memorise the access commands 4 2 Functionality The functionality the information furnace provides encompasses everything it can reli ably and safely accommodate Figure 2 The information furnace should also act as the centralised repository for the home occupants data in a manner analogous to the one suggested by the CyberAll project 25 26 and integrate the home s communication interfaces by pe
57. y generated by other applications Direct Involvement of the Domain Expert The DSL expression style can often be de signed so as to match the format typically used by the domain expert This results in keeping the experts in a very tight software lifecycle loop where they can di rectly specify implement verify and validate without the need of coding inter mediaries Even if the DSL is not high level enough to be used as a specification language by the domain expert it may still be possible to involve the expert in code walkthroughs far more productive than those over code expressed in a gen eral purpose language The DSL used for specifying the alarm daemon behaviour describes a state machine Each state description consists of its name actions to perform when it is entered written on lines starting with a symbol and events that lead to other states denoted using a gt symbol Actions are simply C function calls To enhance the DSL s expressiveness a state can also transfer immediately to another state without waiting for an event I use this feature to modularise the specification by defining subroutine states As an example the sequence in Figure 5 is used to specify that a leave command will arm the system 10s after opening the door A small Perl 37 script transforms the alarm specification into an efficient C loop structure 5 3 Telephone Integration The answering machine fax server PBX programming and alarm
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