pervasive computing technology review

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PERVASIVE COMPUTING TECHNOLOGY REVIEW

Version: Restricted to Smart Internet Participants Only Date of Publication: 12 May 2004 Author: Dr. Aaron Quigley, Senior Research Fellow Smart Internet Technology Research Group School of Information Technologies University of Sydney Australia

Established and supported under the Australian Government’s Cooperative Research Centres Programme

DISCLAIMER & CONFIDENTIALITY This document contains trade secrets and proprietary information of Smart Internet Technology CRC Pty Ltd that is private and confidential and may not be disclosed to third parties without first seeking permission. This Technology Review contains references, comments and projections regarding the topic of Pervasive Computing. The recipient acknowledges that these references, comments and projections reflect assumptions by Smart Internet Technology CRC Pty Ltd concerning the future, which may or may not prove correct. Smart Internet Technology CRC Pty Ltd and its respective directors and officers expressly disclaim any liability, representations or warranties express or implied contained in this Technology Review or any omissions from it. This disclaimer extends to any other information whether written or not, provided at any time to a partner, researcher or student by or on behalf of Smart Internet Technology CRC Pty Ltd. © Smart Internet Technology CRC Pty Ltd 2004. All Rights Reserved. All trademarks mentioned in this document are the property of their respective owners. Smart Internet Technology CRC Bay 8, Suite 9/G12 Australian Technology Park Eveleigh NSW 1430 Australia T: 61 2 8374 5080 Fax: 61 2 8374 5090 www.smartinternet.com.au

Commercial-in-confidence

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MANAGEMENT INTRODUCTION Pervasive Computing – A Technology Review is the first in a series of reviews designed to provide Smart Internet Partners with a global view of R&D activities. This industry-facing report draws on the knowledge acquired by Smart Internet Researchers, though the natural course of their work, looking at current technology directions that impact on the areas in which Smart Internet focus their R&D. The purpose of this report is to increase knowledge of technology and expand awareness of global R&D activities to assist our Partners with strategic direction and provide a positive impact on their business. The distribution of this report is privileged and only Smart Internet Shareholder, Partners, SME Consortium Members, Researchers and Students will be the recipients. A summary version of this report will be made freely available to the general public Any comments or feedback on this report are welcome and should be directed to [email protected]. About the Author: Dr. Aaron J Quigley Senior Research Fellow Smart Internet Technology Research Group School of Information Technologies University of Sydney Dr Aaron Quigley is a Senior Research Fellow in the School of Information Technologies, University of Sydney. His position is fully funded by the Smart Internet Technology CRC. Dr Quigley returned from working at Mitsubishi Electric Research Laboratories (MERL) in Cambridge Massachusetts (USA) to join the Smart Internet Technology CRC. His academic and industrial research experience span issues in context-aware systems, web engineering, software visualisation, and adaptive interfaces. He has published 20 papers in these areas along with a number of recent Pervasive Computing publications. He currently supervises 2 PhD students and associate supervises 2 others (Smart Internet CRC scholars) along with 3 honours students. Dr Quigley is the project leader (within a research team of 5) for two large research projects, namely BlueStar funded by Smart Internet Technology CRC, in conjunction with Telstra and Nightingale a jointly funded project with Smart Internet CRC and the National ICT Australia. Further information on Dr Aaron Quigley can be found at http://www.it.usyd.edu.au/~aquigley.


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CONTENTS CHAPTER 1 PREFACE BY OFFICE FOR THE INFORMATION ECONOMY .................... 5 CHAPTER 2 INTRODUCTION TO PERVASIVE COMPUTING ...................................... 7 CHAPTER 3 RESEARCH AND DEVELOPMENT GROUPS ............................................. 9 3.1 AUSTRALIA & NEW ZEALAND RESEARCH AND DEVELOPMENT ......................... 9 3.2 INDUSTRIAL RESEARCH AND DEVELOPMENT ................................................... 9 3.3 INTERNATIONAL ACADEMIA............................................................................ 12 CHAPTER 4 KEY TECHNOLOGIES............................................................................ 14 4.1 EMBEDDED “COMPUTERS” AND CONTROL ...................................................... 14 4.2 CAR ENVIRONMENTS ....................................................................................... 15 4.3 HOME ENVIRONMENTS .................................................................................... 15 4.4 EMBEDDED IDENTIFICATION .......................................................................... 16 4.5 HANDHELD COMPUTERS .................................................................................. 17 4.6 MIDDLEWARE AND SYSTEM SUPPORT............................................................. 18 4.7 WIRELESS STANDARDS.................................................................................... 20 4.8 MODALITIES AND MORE .................................................................................. 21 CHAPTER 5 END USER APPLICATIONS ................................................................... 22 5.1 SMART SENSORS .............................................................................................. 22 5.2 SMART CARDS AND RFID ................................................................................. 22 5.3 HOME NETWORKS ............................................................................................ 23 5.4 HOME MEDIA HUB ............................................................................................ 23 5.5 MOBILE INFORMATION ACCESS AND GAMING DEVICES ................................ 24 5.6 MOBILE PHONE ................................................................................................ 25 5.7 PERSONAL DIGTIAL ASSISTANT ...................................................................... 25 5.8 WEARABLE COMPUTERS................................................................................... 26 CHAPTER 6 SUMMARY & CONCLUSION.................................................................. 27 SELECTED REFERENCES ......................................................................................... 31 GLOSSARY OF TERMS ............................................................................................. 35


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CHAPTER 1 PREFACE BY OFFICE FOR THE INFORMATION ECONOMY This paper on technology directions in pervasive computing provides an excellent synopsis of global and national research trends. The successful implementation of pervasive computing does not hinge on any particular type of technology but the use of a range of different technologies and end-user applications. Mobile devices, controllers, interfaces, sensors, identity readers and networks all play a role in building a picture of the environmental context that is key for pervasive computing. Pervasive computing appears to hold significant potential for meeting the latent demand for more intuitive and seamless connections with technology. Its ability to understand changes in context and provide a path for convenient access to information and data in a variety of forms permits a simple and effective technology interface to be constructed. These developments could lead to changes in business models and hence industry structure and potential benefits in accessibility for people with special needs. Yet it also has the potential for increased risks to privacy, identity management and tracking movements. Pervasive computing offers significant potential to people with special needs. Neuro-electrical interfaces for controlling virtual devices hold tremendous promise for people with mobility difficulties. In addition, an early demand driver for pervasive computing is likely to be in the health area. This would facilitate remote patient monitoring allowing convalescence to be done in the home rather than using expensive hospital facilities. Broadband connections could aid contact with health staff, health monitoring could be performed remotely using wireless connections to local home hubs and extended support communities could be used to provide additional services. Another potential driver is for home security. The current trend towards household renovations could emerge as an extended trend towards further renovations involving the setting up of home network systems that provide pervasive computing technologies, enhanced security services, remote monitoring, and entertainment hubs. The implementation of interoperable pervasive computing technologies could involve significant changes to current industry structures in the IT, media and telecommunications environment. Pervasive computing is one of the many convergent technology systems that disrupt existing industry sectoral boundaries. Will pervasive computing roll-out be coordinated by new intermediary service providers that aim to achieve interoperability using open standards or will existing technology and communications service providers carve up the market into a series of competing networks with limited interoperability? The answers to this question will have very important implications for regulators in terms of competition, trade and communications as well intellectual property policies if pervasive computing delivers on cross-media functionality. The benefits of pervasive computing environments are considerable yet it is not without risk. Rigorous risk assessments should be required to understand the implications for privacy, identity management and tracking of movements. An important facet in this assessment is that of trust. Organisations want to trust the individuals they deal with and individuals want to be trusted. The National Privacy Principles require organisations to deal appropriately with personal information. The Privacy Commissioner has recently released an excellent paper on the related issues of privacy and identity management which are critical elements to the effective operation of pervasive computing systems. The paper identifies that lazy technology solutions that aggregate vast amounts of electronic information about the movements, transactions and status of a person can actually facilitate identity fraud, rather than ameliorate the risks. The paper notes that the current fabric of society could be threatened by pervasive surveillance from the widespread linkage of information beyond the control of the individuals concerned. The Commissioner points out processes that favour good identity management and these should be seriously considered by technology researchers and commercial users. These processes should allow for multiple identities, require transactions to be authenticated


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without identity authentication, for the individuals to retain control over their personal information, and decouple identifiers from personal information and links between systems. This will lead to perspectives from the individual of increased control and trust; control over their own personal information and trust that organisations will handle this information appropriately. Organisations then, need to look at efficient data management to build in privacy into their technology systems, rather than add it as an afterthought. The development of pervasive computing is still in its infancy, similar to where the development of personal computers was before their mass production. Technology will become pervasive, of that there is little doubt although the extent and speed of its introduction will be determined by supply-side factors such as the quality of research and demand-side factors including take-up. Another demand side factor is if sufficient evidence is published of electro-magnetic radiation causing health effects such as cancer, a factor that could significantly impact on the development of pervasive mobile networks. The role of the Australian Government will remain important to the effective implementation of future pervasive computing systems. Spectrum allocation to enable pervasive computing to emerge may be required although some communications technologies that permit distributed networks of devices to make collective use of available bandwidth may overcome spectrum scarcity issues. Apart from providing funding to existing programs that assist in research into these technologies such as that of the Smart Internet Technology CRC, Government is facilitating and encouraging the development and rollout of broadband networks through its National Broadband Strategy. It is also looking to implement innovative e-government solutions using mobile devices to augment its existing online and traditional service offerings. In addition, Government is playing a catalytic role in the development of interoperable standards to permit the flow of information between disparate networks and the development of frameworks for business protocols to address business and regulatory aspects of issues such as privacy, authentication and trust. Luke Naismith Policy Analyst Information Economy Division Department of Communications, Information Technology and the Arts


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CHAPTER 2 INTRODUCTION TO PERVASIVE COMPUTING

"Ubiquitous computing names the third wave in computing, just now beginning. First were mainframes, each shared by lots of people. Now we are in the personal computing era, person and machine staring uneasily at each other across the desktop. Next comes ubiquitous computing, or the age of calm technology, when technology recedes into the background of our lives." --Mark Weiser [1]

The central tenet of pervasive computing is focussed on providing support for our developing application needs in the new information economy [2,5,6]. Individuals and corporations are increasingly producing and consuming data that needs to be accessible regardless of physical location or constrained computing support. Pervasive or ubiquitous computing represents an evolution from the notion of a computer as a single interconnected device, to the notion of a computing space comprising personal and peripheral computing elements and services [2]. Due to the uncertainty of predicting future technology developments, it is unclear whether or not we are entering a third wave of pervasive computing. However, we can chart the waves of computing over the past 50 and suggest changes for the coming 10 years [3,6]. The following waves are in relation to the number of computers per individual which include, •

Very few, mainframe computers (60-70’s) executing big data processing applications.

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Few, desktop computers (80-00’s) for individual business or personal related activities, connected in wired networks to the global Internet.

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Many, compute devices (00-10’s) for wired or wireless anywhere, anytime data access.

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Tens/hundreds of pervasive computing devices (10’s-?) becoming “invisible” and part of the environment forming personal, peripheral and intelligent environments.

The consensus in the research and development community is that a move to pervasive computing will occur if user expectations on what constitutes a computing device and service evolve and morph. The shift in expectation is from something tied to a simple networked computing device, to an intelligent information service that is accessible whenever and wherever you need it [2,4,5]. The basic principal in pervasive computing is that people should be able to access information services regardless of the actual technology or connectivity currently available. To motivate further discussion we provide a number of examples “pervasive computing applications” from 7,5,3 and 1 year ago before presenting a review of current global research and development in the next Chapter. •

7: Bat tracking system from AT&T Cambridge research laboratories UK. Small devices can be tracking from a roof-mounted infrastructure, which supports locating devices, people, remote interaction and context [7,8].

•

5: Home automation system from Phillips research laboratories Holland [9]. PDA/Phone based interface to remotely control lights, air, television etc.


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3: Aquarium tour guide system, University of Genoa Italy, Hypermedia location aware handheld guide system to interact with multimedia [10].

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1: Gesture recognition system, Electro Communication University Tokyo Japan, computer vision based gesture input system for interaction [11].

To realise this vision there are a number of social, legal and technical challenges to address. We here describe a number of the core technical challenges that this report will cover, which include cheap low-power devices [56,60,61], user interfaces [14,21,34,42], middleware [12,68,80], positioning [13,29,40,43,46], security [2,3,5,63], low-power networking [60,61,62,67], dynamic interfaces [6,20,21,23,38,41], operating systems [38,41,49,57,79], privacy [13,53,57,73], local service discovery and use [51,49,65,80], device management [31,47,62,63], service coordination [27,30,51,54,58], intelligent environments [12,38,41,51,49,81], invisible interfaces [11,35,37,42] and context-aware computing [51,52,53,54].


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CHAPTER 3 RESEARCH AND DEVELOPMENT GROUPS 3.1 AUSTRALIA & NEW ZEALAND RESEARCH AND DEVELOPMENT Existing research and development in Pervasive Computing within Australia and New Zealand is primarily focused around the CRC research program, with new research efforts coming from groups such as NICTA (AUS) or HitLab (NZ). Given the description of Pervasive Computing presented in Chapter 1, many of the current research projects within Smart Internet are in the area of pervasive computing [12,13,14]. For example, the MICA project in the NAUI program constitutes a middleware system for multi-model application support in Pervasive Computing. The Nightingale project in the IE program constitutes a data, context and application architecture for Pervasive Computing. This system supports a personal and peripheral area network to provide invisible or natural interfaces for reminiscence applications for the elderly. Enterprise Distributed Systems Technology Centre (eDSTC) is a CRC based in Queensland that has research projects, technologies and spin offs related to pervasive computing. Elvin is a publish-subscribe system used around the world for deploying loosely coupled component based systems, written in different languages. Other projects include Universal Interaction and Control in Multi Display Environments, an E-World Laboratory based in the University of South Australia (eDSTC node since 2003), LiveSpaces and Enterprise Enabled Ubiquitous Workspaces, Ambience – Location management and context, M3 – Mediated Peer Exchange and a Building as Media Project. Most researchers within pervasive computing in the DSTO, Monash, UTS, UQ or UoSA are affiliated with the eDSTC and as such are involved in these projects [19]. The newly formed Australian Centre for Interaction Design has a number of new IT projects, of which its location based games initiative is most relevant. This project ties into and extends work done in the Equator project in the UK by some of the core researchers and has commercial backing for eventual development and deployment [18]. The National ICT Australia includes a specific program in networks and pervasive computing (NPC) with the aim to develop pervasive applications, network infrastructure and environmental instrumentation [15]. Current NPC NICTA projects include mobile networking, smart sensors and body worn sensor networks. The recently formed Humans Understanding Machines (HUM) program aims to explore many of the human computer interaction problems that are common in smart spaces or augmented environments. [16] HitLab New Zealand based in Christchurch is a sister-research laboratory affiliated with the Human Interaction Technology Laboratory from the University of Washington. This laboratory is focused on research in the overlapping areas of computer supported cooperative work, tangible user interfaces and perceptual user interfaces. Many of the current projects, many with its commercial consortium members, are focused on the use of Augmented Reality systems for human computer interaction [17]. 3.2 INDUSTRIAL RESEARCH AND DEVELOPMENT Microsoft research Microsoft Research has a number of pervasive computing projects and programs. The Smart Personal Object Technology (SPOT) project has developed a low-power device platform for simple data access and display [39]. Each device is designed to listen for digitally encoded data such as news, weather, personal messages, traffic and directories broadcast on a subcarrier wave of FM transmissions. Recent research from Microsoft on RightSPOT has developed a simple method for approximately self-positioning based on signal strengths from existing FM radio stations. This work complements earlier work from Microsoft on the RADAR


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system which uses an RF in-building user positioning system based on signal strength from 802.11b wireless LAN technology [40]. The larger EasyLiving research program also has a project for tracking people [41]. The Person Tracker uses two stereo cameras to track up to three people in a room using computer vision techniques. This tracking system supports the core function of “disaggregated” computing. Akin to the Activity Zones from MIT, EasyLiving includes a model of space used to indicate places in the environment associated with specific context features. Hewlett Packard The “CoolTown Project” at HP Labs is interested in the development of a location infrastructure for a wide range of clients, whatever the source and meaning of the location, and whatever the client. Their work on building an infrastructure is based on the assumption that the physical location can be provided from the cellular or enterprise-wide network, from a GPS signal or even a user, and all these techniques are likely to co-exist. The goal for this project is a drive towards a pervasive computing infrastructure that can be accessed in a consistent manner across all these technologies, and especially that it can be made available to value-added service providers. This research clearly aims to lead by committee in the development of an industry-wide standard for pervasive computing services based on XML location descriptors [20]. IBM IBM research has a large umbrella program in Pervasive Computing. Researchers from Watson researchers have developed an architecture and framework for a steerable interface system [22]. With such an interface the user can steer the relevant input and output capabilities around the current computing space, taking advantages of the various input and output modalities available. This is a model of embodied computing that moves the notion of a computer from a fixed device into a service or dynamic presence with which we can interact regardless of the currently available modalities [21,23]. This approach has a very Windowsoriented view of human computer interaction. While this project is far from complete it is a compelling example of the time and resources large organizations are devoting to the exploration of methods and techniques and technologies to support the paradigm shift toward pervasive computing. An older project from IBM is the BlueBoard, which is the canonical computer supported cooperative whiteboard application. Users check in with the board using a physical token or a HID brand reader [24]. IBM’s Project Smart Pad introduced pervasive computing to the supermarket [25]. This project sought to enhance consumers’ experience by combining their in-store and online purchases to create services delivered on a customized mobile device equipped with a barcode scanner. The system is available today in most UK Safeway supermarkets as the Easi-Order consumer appliance, a Palm-based device. Other research projects within IBM such as BlueEyes (for eye tracking) and ViaVoice (for speech recognition) are reported on in a later Smart Internet Technology Report on multimodal user interfaces. Intel Researchers in the Open Source Robotics research Initiative at Intel have developed a Relationship Management system that is focused on local identity management, for pervasive computing [26]. Their technical goal in this project is to explore how to integrate GPRS and ad hoc wireless networks to facilitate secure and user-friendly collaboration. The system runs on desktops, laptops, and PDAs, and groups of people can use it to securely share documents, text messages, and other electronic media. Related projects include the JXTA project from SUN [27], Groove [28], Speakeasy [29] and Enclaves [30]. Each system is typically client-based and supports ad hoc peer-to-peer messaging, key authentication, and distributed knowledge. Other researchers within the Intel research Personal Server team has developed the Personal Server, which is a mobile device that lets the user store and access data and applications


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through interfaces found in the environment [31]. The Personal Server does not use a display; it wirelessly connects to nearby input and output devices. Ethnographic research has shown that users have access to several output devices (shared or personal) about 70 percent of the time. These devices include televisions, desktop computers, printers, laptop computers, PDAs and video projectors [32]. Researchers within Intel’s UK research labs have developed self-surveying methods for capturing fine-grained radio survey data; commonly used in many RF based positioning systems. Researchers in Intel Berkeley are exploring the need for context toolkits and user studies on their perceptions about loss of control with pervasive computing systems [33,34]. Others have used focus groups and contextual interviews along with the experience sampling method (ESM). ESM uses a timing device to trigger self-report diary entries or using handheld computers various survey questions. Ethnographic or user centred design work, whether in the form of living laboratories, augmented homes, user study, cultural probes or tracking technologies forms a substantive component of pervasive computing research. A later Smart Internet Technology Report, on User Centred Design, will more completely review UCD. MERL The DiamondTouch is a collaborative touch sensitive large desktop system from Mitsubishi Electric Research Laboratories (MERL), Cambridge USA [35]. This projected flat work surface is suitable for groups collaborating around a table. The touch sensitive surface is realised by passing a small-modulated electrical current through each participant, which is picked up by an array of antenna under the surface of the DiamondTouch. Such devices are envisaged for smart spaces or fixed intelligent environments that break away from the screen-keyboardmouse metaphor, rather than ad-hoc pervasive computing interactions. In this regard the DiamondTouch is functionally similar to the PARC CoLab project [36], the SmartSkin project from Sony [37], the MIMIO or the BlueBoard from IBM. A leading example of a support system for smart spaces is the now open source iROS system from Stanford University. The Stanford Interactive Workspaces project is exploring the use of iROS in iRooms for collaborative interaction in physical spaces augmented with displays, wireless access, PDAs, laptops, scanners and cameras [38]. AT&T Researchers within AT&T have developed the Personal Shopping Assistant that was an early laboratory prototype, as part of the Personal Mobile Terminal Project. This prototype used RFID for location-based services and a barcode reader for product reading with some personalization features. Other pervasive computing research within the AT&T Research lab in Cambridge, UK saw the development of a local positioning system called the Active Bat [7]. This system consists of a controller, a fixed node receiver infrastructure and a number of active bat tags. Each tag emits an ultrasonic pulse directed to a matrix of receiving nodes mounted on the ceiling in each room; empirical results show the system can achieve sub 10cm accuracy. More recently researchers in the University of Cambridge have used this system to build 3D world models of physical environments [8]. NTT NTT DoCoMo Japan offers pro-active and passive services based on your location, activity and friends. “Friends finder” sees your location information is pushed to friends on a buddy list, when you are within half a kilometre and iArea contextualises your search based on activity and location. Electronic city guides based on the iArea service personalise the content shown based on a user model, history and location.


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3.3 INTERNATIONAL ACADEMIA Portolano: University of Washington An umbrella project within Washington University, supported by DARPA and Xerox PARC, for pervasive computing research is the Portolano effort. While it is unclear how cohesive this effort is, a number of interesting projects under its umbrella have developed. Labscape is a pervasive computing system for keeping tracking and monitoring activities in a science laboratory [44]. Another project is the Activity Compass, a device that helps guide a cognitively impaired person safely though the community. The displayMote project leverages the UC Berkeley mote system to deliver small lower power display devices. The Location Stack project has developed methods for sensor fusion for context-aware systems [43]. While more fundamental research in Portolano is based on using Bayesian models for inferring high level behaviours from low level sensors, primarily from positioning. Oxygen: Massachutts Institute of Technology MIT’s Project Oxygen is a human-centric pervasive computing effort and combines research (MIT’s Artificial Intelligence Laboratory and Laboratory for Computer Science) and industrial (Acer, Delta, Hewlett-Packard, Nokia, NTT and Philips) involvement [45]. A number of pervasive computing projects have been developed under the MIT umbrella such as Activity Zones, Metaglue and the cricket system [46]. Activity Zones are based on providing computing support to a physical space that has been decomposed into areas that support particular human activities. The decomposition is discovered in bottom-up observational manner or imposed organisationally in a top-down manner. The Metaglue system is an approach for integrating interacting components, which in its current distribution comprises more than a hundred agents. It is possible to develop new agents fairly easily because the base is solid. The Cricket system uses a combination of RF and ultrasound technologies, which allow a small “listener” device, which can be carried or attached to equipment, to estimate its distance to the closet beacon. The infrastructure is based on a number of ceiling-mounted beacons networked together. The beacons transmit an RF pulse to a device called a listener. Each listener, upon receipt of the first few RF bits from the beacon turns on its ultrasonic receiver to listen for the upcoming ultrasonic pulse and location data. Based on the measured time difference between the first RF signal and the ultrasonic signal, the cricket device can determine the distance to the beacon. The benefits of this approach are its decentralized scalability with no grid of ceiling sensors as mobile listeners perform the timing and computation functions, user privacy and low cost. The benefits also point to the system’s drawbacks, decentralised architecture, and receiver side computation and hence power burden on each listener [46]. A living laboratory (supported by the House_n consortium) has recently been completed in an apartment close to MIT for further user study. This laboratory includes various sensors, actuators, cameras and other controls. The aim is to study user behaviour within a pervasive computing system in a natural setting, using observation tools. AwareHome: Georgia Institute of Technology Georgia tech researchers have developed a large number of pervasive computing systems and applications under the umbrella project called the AwareHome, similar to those described [47]. Their user positioning and tracking system comprises of RFID based floor mats and door readers along with identifying people based on their footstep force profiles. Various floor tiles are outfitted with force measuring sensors and are used as data gathers as users walk over the tile to identify them. A number of applications such as check in-out board, remote family awareness, digital memory archive and video based reminder applications are supported. While wearable computing is a related area of research and development, it is of interest to pervasive computing researchers as evidenced by strands in pervasive computing conferences, journals and workshops. Researchers in groups such as the ETH Wearable Computing Laboratory and Georgia Institute of Technology are developing novel interaction techniques, based on speech, gesture and special devices for interaction.


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Aura: Carnegie Mellon University A team of researchers at Carnegie Mellon University (CMU) has proposed a six-layered Aura architecture for pervasive computing along with algorithms, interfaces and evaluation techniques to realise Aura [49]. The first layer consists of Prism, a layer above the application layer for task support, user intent and proactive computing. Spectra, for remote execution and Aura runtime support constitute the third layer. A nomadic file access system named Coda [48] and a system for resource monitoring and adaptation called Odyssey forms the fourth layer. A Linux kernel and intelligent networking constitute the final two layers. This architecture is specifically intended as an umbrella project for pervasive computing research involving wireless communication, wearable or handheld computers and smart spaces. Elements of this architecture are already implemented from the Open Source community (Linux) or from existing CMU projects (Coda, Odyssey). Current reported research in this project can be summarised as follows: adaptation of coda and odyssey to pervasive computing demands, development of Spectra that uses context to decide how to best execute a remote call, Prisim a system for capturing and managing user intent, which is decoupled from the actual applications. Aura proposes to use cyber foraging to amplify the capabilities of resource constrained mobile devices through the use of compute servers and data staging servers (surrogates) in the physical environment. Researchers have also developed and tested a number of context-aware applications based on the 802.11b positioning system and a wireless bandwidth prediction model based on historical traffic patterns. Neuroengineering: NASA Researchers at the Neuroengineering lab within NASA are developing neuroelectric interfaces for controlling virtual devices. Their approach uses hand gestures to interface with a computer rather than relying on mechanical devices such as joysticks and keyboards. Their methods rely on electromyogram (EMG) signals from the muscles used to perform these gestures. The current system interprets muscular motion and translates these signals into useful computer commands. Other approaches, which will be more completely described in later reports, such as the Vkey allow touch typing through light projection or use an external camera that requires sophisticated image processing (such as Intel’s Open Source Computer Vision Library system), with the use of simple marker tracking (such as the Trimble system with the Artoolkit from the HitLabs), or hybrid approaches such as those developed in ETH’s perceptual computing and computer vision group or through a sensing glove on the participant’s hand.


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CHAPTER 4 KEY TECHNOLOGIES Research and development in pervasive computing is attempting to take the current context of the human activity into account when interacting with the user. As such, the key technologies for pervasive computing revolve around the ability to capture, maintain, transmit and codify computational and environmental context data. Context includes information from the sensed environment (environmental state) and computational environment (computational state) that can be provided to alter an application’s behaviour [51]. “Context is any information that can be used to describe the situation of an entity. An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and application themselves” [53]. Context information includes spatial (location, speed), identity (users and others in vicinity), user model (profile, preferences), temporal (time of day or year), environmental (noise, light), social (meeting, party), resources (printers, fax, wireless access), computing (network bandwidth, login), physiological (hearing, heart rate), activity (supervision, interview), schedules and agendas [51,52,53,54,55]. Based on this, context-aware applications typically fall into the three broad categories of adaptive, proactive, and automatic. To support the seamless interaction across a number of devices, context-aware applications attempt to reduce the cognitive burden on the user by offering services that are adaptive, proactive, or automatic.

To be inserted

Consider a home environment such as that shown which has been instrumented to collect contextual information. In such a set-up there will be embedded computers and control elements, identification and authentication elements, a home network, an entertainment or media hub, wireless networking, service discovery [58], middleware and operating system support [57], handheld computers for data access throughout the home and a car network for data access once out of the home and on the move.

Considering this, we now review the key technologies that exist to allow researchers and developers to realise current and future forms of pervasive computing systems. 4.1 EMBEDDED “COMPUTERS” AND CONTROL The move towards a pervasive computing environment entails a proliferation of embedded sensors, actuators and smart controls in the physical environment [56,60,61]. Such devices are connected to a network, in some manner, either through a temporary connection or a permanent on-demand connection. The connection can be wired (using twisted-pair, Ethernet or power-line) or wireless. A noted, the connection need not be permanent but can exist periodically to allow communication. A sensor is a small, self-contained device used to collect measurements such as air/liquid temperature, pressure, light level, vibration, sound level, heat level and gasses. Sensors can be built into other devices or can be based on the input or sensing functionality provided by such devices. An example of this is a microphone on a device used to measure sound level. An actuator is a device that accepts commands from a remote system to act on their environment, such as activating a motor to open a window or let water flow, or turning on and off electrical switches. As with sensors, an actuator may be an embedded output function of a device that is network accessible. A smart control consists Commercial-in-confidence

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of control logic and communication logic to make a sensor or actuator “smart”. The communication logic connects the control device with the wired or wireless network, as appropriate. The packing/unpacking and communication protocols are maintained here. The control logic interprets commands from the network and manages communication with the sensor or actuator. 4.2 CAR ENVIRONMENTS Smart sensors and smart actuators are simply some of the core elements of a pervasive computing or smart environment. The automotive industry has been among the first to deploy physical environments for consumers equipped with these elements. There has been an emerging demand for new on-board computing systems in vehicles to make them more efficient and to make driving easier, safer and more comfortable. A system such as OSEK, which is a real-time vehicle controller/operating system, is now in use by European manufacturers [62]. In-vehicle networks are based on a generic bus system that allows interconnection of components, which might be created after the bus was defined. An example of this is the Controller Area Network (CAN) which uses a twisted pair for the physical layer and defines three classes of system based on traffic speed (10kbps-1Mbps) ISO 11898 [63]. Bus network systems such as CAN or J1850 use priorities to abort lower priority traffic and all connected nodes receive each message. Smart sensors are now fitted throughout vehicles to measure fuel levels, oil levels, tyre pressure, or even sunshine and rain. Data from these sensors is transmitted over in-car networks to various processing modules that activate actuators whose actions we don’t see or warnings or notifications that we do. Some of this sensor data is aggregated and stored and is available through physical diagnostic interfaces as defined by ISO 9141. It is a matter of time before this data is accessible to the occupants of the vehicle for their use in other applications. The majority of these systems provide functions relating to the vehicles’ purpose as a safe and efficient transportation device. The car as a platform for pervasive computing is compelling due to its size, cost and availability of power. Research and development in this area is focusing on in-car speech recognition, gestural interfaces, alternate user interfaces, location-based services, in-car entertainment and navigation systems. GPS in-car navigation is one of the oldest car-based consumer add-on systems available. Current state of the art deployments use GPS signals, tyre rotation, histories and mapping data to locate the car along with presenting accurate simulated 3D city views for city driving and using text-to-speech for verbal output of direction [74]. 4.3 HOME ENVIRONMENTS In the Internet-connected home of 2004 there are typically two separate networks. There are entertainment devices, such as television, DVD and radio. These are connected via cable, satellite or analogue radio frequencies. Computers and other computing devices communicate using digital communication over phone or cable lines. The integration and possibly merging of these two disparate networks will accelerate the development of novel applications in the areas of digital television, interactive entertainment, high definition television, on-demand content and personal media recorders. While the internet and entertainment networks converge and de facto standards emerge through cooperation or market dominance there are already a range of home network solutions for the “Smart Home” that use smart sensors and actuators for security, environmental control or entertainment. The current smart home typically consists of a control system and a number of always on networked smart sensors and smart actuators throughout the home. The networking is achieved through the use of a wired home network, phone line network, power line network, and more recently with radio frequency networking or some hybrid approach. For power line networking the basic method is to send the data as a high-frequency signal on top of the


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low-frequency power wave, as used in the X10 standard. Various high-frequency bands in the range 10kHz up to 525 kHz are regulated in different countries for this. However problems using power lines include noise from devices plugged into the power line, signal distortion, signal loss, or devices that act as line filters. X10 is a limited narrow-band system (120hHz, 300bps) that supports addressing of up to 256 local devices and supports a simple command language such as on, off or dim. While this standard is being updated, its general applicability for home networking is limited [67]. There are a number of key standards and working groups in this area that we will now review. The homeRF working group has established an open standard for wireless communication between PCs and other electronic devices [67]. The homePNA group has developed a specification, using telephone wiring, for home networking (1-10Mbps). The Open Services Gateway Initiative has defined a gateway component for residential service gateways to the Internet. The HomePlug PowerLine Alliance and the CEBus Industry Council continue to develop complementary standards and application languages for power line networking. CEBus uses a spread spectrum standard to transmit data at a higher rate (210kbps) and describes a packet format, transfer protocol, peer-to-peer networking and a common application language [69]. 4.4 EMBEDDED IDENTIFICATION The need to have robust decentralised identification and authentication resulted in the development of the “smart card” [70]. Smart cards consist of a robust single-chip microcomputer with sophisticated countermeasures to guard the chip and the data it contains from various attacks. Both physical and design measures are used to ensure that even physical examination of the chip or its power supply typically fail. These devices have evolved from magnetic stripe cards and plastic IDs and are used as phone cards, bankcards, and cash cards and to hold medical records. A typical card consists of an 8-bit microprocessor, which allows the device to perform computation such as cryptographic functions. By supporting such functions, secure data in the form of keys never need leave the chip. Today’s smart cards, which are fabricated onto a single chip, have the equivalent power of the first PC and are based on the ISO 7816 series. This includes an 8 bit, 5 MHz processor, 16kb of ROM (written during chip production), 16kb EEPROM (used for permanent storage of data, such as keys) and 4kb RAM (for temporary working storage). Card readers exist either as peripheral devices or are built into the form factor of principal device, such as teller machine, telephones, vending machines etc. The applications to support the card reside both on the card and on the system with the reader. The protocol stack for communication between card and reader has an application and a layer for the transfer of Application Protocol Data units and a transfer protocol layer. Open standards, such as the OpenCard Framework (OCF) and a reference implementation based on Java from Sun are available. [72] A number of commercial and academic research and development projects are investigating the use of RFID or Radio Frequency ID tags (smart tags) for user or product identification and tracking. These tags, which can be 1/3 mm thick, are similar to smart cards as they can store data and perform computation but are also attached to larger radio frequency antenna coil. As the basic tag doesn’t have a power supply, it obtains power from the radio frequency field emitted by the reader (typically 13.56 MHz) [73]. RFIDs can have indefinitely long life cycles because they do not require batteries to maintain the wake-and-query cycle, instead the antenna receives the radio waves and this energy is converted in the tag into power for the chip operation. Data is overlaid (modulated) on the carrier wave (in both directions) for communication between the chip and the reader (typically 26 kpbs). Collision avoidance methods allow several tags to be communicated with simultaneously from a single reader (up to 30 per second).


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4.5 HANDHELD COMPUTERS Handheld computers are battery powered, lightweight, sometimes with wireless connectivity and typically fit into a pocket. Such devices can be classified into a number of sub-categories, which are constantly evolving and morphing into one another. Our classification is based on the principal feature of each class, which include: •

Special purpose computation/service device

•

Information access device

•

Games device

•

Mobile phone

•

Personal Digital Assistant (PDA).

The special purpose computation/service class includes devices such as calculators, GPS receivers, field measurement devices etc. While this class of device is prolific in our environment is does not form a substantive component of pervasive computing. However this will change as these devices continue to incorporate wireless connectivity (such as Bluetooth) and begin to expose their interfaces and services to other devices in a well-defined manner. For example, GPS devices with Bluetooth connectivity, with well-defined APIs for remote access are now available. If incorporated into a large computing space, any application can become location-aware simply by using the location context provided by this device in the current computing space. The information access device class forms what is currently a niche area as the device is typically special purpose and doesn’t form part of a larger computing space. Regardless, such devices are of great interest for applied pervasive computing as they offer always on, alwaysconnected wireless access to information. The canonical example of an information access device is the blackberry system, which was introduced in North America in 1999 and in Australia in late 2003 [75]. Handheld games devices and hybrid games devices are described in Chapter 4. The mobile telephone is the most ubiquitous handheld computing device today. They have evolved from simple person-to-person voice interfaces through devices offering data transmission (SMS). Today most cellular phones are based on a number of competing or complementary operating systems; these include RTOS from Siemens, GEOS from Geoworks, Symbian/EPOC, and Windows for Phones (SmartPhone). Each system, as implemented by the respective mobile phone provider such as Nokia or Motorola, allows for a number of phone specific features, applications and functions along with access to technologies or services which may be supported by the telecommunication operators, such as WAP, MMS or GPRS. The communication technology used for voice and data transfer between a mobile phone and the telecommunication operators differs from country to country and between urban and rural areas. The global system for mobile communication (GSM) is the current de facto standard for wireless voice and data communications. A network of interconnected GSM base stations provides the telecommunication operators, such as Telstra, Optus and Vodaphone, with their consumer coverage. GSM is deployed in more than 100 countries. The GSM standard ensures interoperability; the use of Subscriber Identity Modules (SIM) functions as a secure token for decentralised user identification, authentication and security. Roaming agreements allow customers with one provider to get GSM access through other providers. GSM base station equipment uses either 900,1800 or 1900 MHz, where tri-band phones support all bands giving allowing users to travel between countries using different bands. There are a number


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of ways of transmitting and accessing data through the GSM network. The Short Message Service, originally designed for operators to broadcast messages to end-consumers, allows text messages of up to 160 characters to be sent between GSM mobile phones. GSM data, at 9.6kpbs is part of the GSM standard but has been identified as a bottleneck to data transmission. This has resulted in the development of the General Packet Radio Service (GPRS) as an enhancement to GSM that supports a packet based communication up to 115kbps. While GSM is the most common standard other digital standards for cellular communications exist; these include CDMA, TDMA and UMTS. Code Division Multiple Access (CDMA) is common in North America, part of Asia and in rural areas such as the outback in Australia. The coverage cost of base stations and handsets are typically lower than for GSM but the support for data access is limited. Time division multiple access (TDMA) is similar but has improved bandwidth. Finally, Universal Mobile Telecommunication System (UMTS) is a worldwide standard which allows high-speed data transmission (100kpbs – 2Mbps). Phones and network support for this standard are typically referred to as 3G. Although billions of dollars have been invested in licensing 3G spectrums from various governments around the world, to date, the FOMA [77] network in Japan along with the 3 networks in the UK and Australia are the largest deployments of technology based on this standard. The mobile telephone has already seen its killer app, namely voice communication and GSM has had great success with SMS but the killer app for UMTS remains illusive. Surprisingly, the greatest threat to this form of voice and data transmission may come from the proliferation of local area wireless technologies such as Bluetooth, Wi-Fi (802.11) or Ultra Wide Band (UWB), which may render the need for a wide scale 3G network mute. We will return to these particular technologies later in this report. The final class of handheld computer is the Personal Digital Assistant (PDA). Apple introduced the first well-known PDA in 1993 with its much-maligned Newton, due to form factor and poor handwriting recognition. While this PDA was retired in 1998 it is still supported by enthusiast with recent additions for GPRS and 802.11 along with software for playing MP3s. The current top of the line PDA device has a colour screen, finger print reader, better synchronisation support, Internet capabilities, cached WWW access, wireless networking, more memory, support for memory cards, and more applications. There are also a broad class of PDA/Phones, which have the form factor of a PDA (XDA) or a mobile phone (Nokia 6600, Kyocera). 4.6 MIDDLEWARE AND SYSTEM SUPPORT Pervasive computing middleware is a software architecture that acts as an intermediary between applications, processes, services and devices in changing or evolving computing spaces. A number of systems have been proposed for simple, seamless, and scaleable device interoperability using the notion of service discovery where the rate of change or evolution is low and some notion of a fixed infrastructure is prevalent. A device or application that support service discovery has the means to make other devices or applications aware of its presence in the network, the ability to publish in a well understood manner the services it offers, the means to find and/or use a service, mechanisms to support coordination among peers and zero configuration. Three well established and industry accepted standards now exist, namely Jini [80], Salutation and UPnP. Given the definition above, technologies such as Web Services, CORBA, RMI and RPC do not qualify but may be used to realise the above standards. Jini is a JAVA-based technology from Sun Microsystems for developing robust network based distributed systems. Jini consists of a model of operation for a Jini network, protocols, classes, interfaces and services. The services typically run on a group of networked computers each running a JVM and the capability of using RMI (although CORBA or any other


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remote invocation scheme can be used). Proxies can be used for devices or applications that do not have their own JVM. The proxy acts on behalf of the devices and forwards commands to it [80]. Jini includes the notions of services, groups and federations. A group is a meaningful logical boundary imposed by the Jini network implementers (e.g. department or workgroup); groups passively partition the physical Jini network for multicast discovery purposes. A federation may be independent of any group partitioning or any particular discovery protocol. Instead, it is simply a temporary union of Jini clients and services that form to complete a work task. Overall, the Jini network is a collection of services where clients dynamically combine these services into collections called federations, to complete some computation. A discovery and join protocol is specified to allow a device to enter a Jini system and advertise its services to others. To bootstrap a new device which enters a Jini system it attempts the discovery step (multi-cast) to find a lookup service to register itself (join) and later its services with. A lookup service is a logical central repository that stores information about all devices and services in the Jini system. Once a lookup service is located the device uses the join protocol to register with the lookup service, which replies with a service object, which contains Java language interfaces to the lookup service. All subsequent object references are obtained using this initial reference for lookup. As this is a loosely coupled approach to distributed computing, services must publish themselves by registering their proxies with one or more lookup services. A client locates a service through a lookup and downloads the service’s proxy object and then starts interacting with the service directly (avoiding further communication with the lookup). Sun’s reference implementation of the discovery process and lookup service (Reggie) is RMI-dependent although Jini itself is not. A service, on a particular device, is given a lease, which it must renew with the lookup to help ensure entries are accurate and up to date. Jini contains helper utilities and classes to support service failure, self-healing, distributed object stores, distributed transactions and lease management. Salutation is architecture to enable devices to discover and use services provided by other devices in the network. Each device on the network registers with a salutation manager. The salutation manager communicates with a transport manager to decouple it from the network protocol used for communication. The registry contains information about locally connected services or remote services accessible from other salutation managers. Clients requesting specific service types from the manager perform Service discovery. The manager established a service session between client and service, using Salutation defined messaging protocols. UPnP is an industry led effort by Microsoft using XML over TCP/IP to describe the services and capabilities a device is offering. Each device needs an IP address assigned by a DHCP server or using Auto IP in a network without a DCHP server. Auto IP picks an IP from a reserved range, and then broadcasts its intention to use this address. If no one else replies, it assumes no conflict. As with Jini, discovery is the first step in the UPnP protocol but this is then followed by description, control, eventing and presentation. In the description step the device sends a URL to the control point, which uses it to retrieve the device description document from the device (including the URLs for eventing, control and presentation). The control point retrieves the descriptions of the services the device offers (based on an UPnP service template in XML). If one of the services states variables changes, the device publishes a notification using the eventing mechanism. The control point can also present some device information or control methods for a user from the presentation URL. Service invocation is not included in UPnP, instead it is up to the devices to determine how to interact and use each other’s services [65].


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4.7 WIRELESS STANDARDS The two main local area wireless systems available today are Bluetooth and 802.11(a/b/g) (Airport, Wi-Fi) with an emerging trend in Ultra Wide Band (UWB) networking. Bluetooth and 802.11, while occupying the same frequency range, are complementary wireless technologies. Bluetooth is designed to be a low-power cable replacement between cell phones, laptops, and other computing and communication devices within 10 meters. 802.11 can be thought of as wireless Ethernet; it can extend or replace wired networks for dozens of computing devices within 100 meters. Bluetooth has a basic data rate of 1 Mbps, which makes it suitable for connecting up to 8 devices in a “Piconet” such as printers, scanners, keyboards and mice. Within one Piconet, one device acts as master while others act as slaves (which synchronise their clocks with the master). A “Scatternet” is formed by two or more overlapping Piconets; devices may communicate inter-Piconet but are not synchronized. Due to a specific part of the Bluetooth stack, dealing with audio connections, it is also suitable for real-time voice connections between headset and phone. For Bluetooth the available frequencies are in the ISM (Industrial, Scientific, Medical) band of 2.45 GHz band. This band is divided into 78 carrier frequencies, spaced 1 MHz apart. As each carrier is divided into time slots of 625 microseconds, each slot carries 625 bits to support the basic data rate of 1 Mbps. Clearly, some of these bits are used for control messaging, error correction and synchronisation so the basic rate is reduced. The Bluetooth standard mandates a pseudo-random frequency-hopping pattern (1600 hops/s), which sender and receiver must synchronise on, to increase robustness and noise immunity. Each Bluetooth packet consists of an access code (72 bits), header (54 bits) and payload (up to 2745 bits). A packet may be up to 5 slots long (using the same hopping frequency). Communication between devices in a Piconet can be synchronous connection-oriented (SCO) or asynchronous connection-less (ACL). SCO represents a dedicated point-to-point connection between master and slave reserving communication slots for real-time applications such as voice at 64 kbps. Bluetooth devices will support a mixture of SCO and ACL channels. The entire Bluetooth protocol stack goes well beyond the radio link. The link manager protocol defines messages that are exchanged between devices in a Piconet to setup and maintain links. Authentication is carried out using a challenge-response protocol with cryptographic keys. Devices may also agree on common encryption parameters. The logical link control and adaptation protocol (L2CAP) is used by the upper-layer protocols for data transport although the audio protocol can bypass L2CAP to use a SCO link directly (for performance reasons, as noted). RFCOMM provides logical RS-232 port emulation for applications or higher-level protocols. An Internet protocol stack, including UDP and TCP, can be implemented using point-to-point protocol as an interface to RFCOMM. Other protocols include the Object Exchange Protocol (OBEX), which provides a session layer service for applications such as synchronisation and file transfer, Advanced Telephony protocol to enable telephony and fax transfer, and Bluetooth Telephone Control protocol. The final protocol, which relates to UPnP and Jini described earlier, is the service discovery protocol (SDP). This protocol, as with all service discovery, is used to find new services as they become available and deregister services as they become unavailable. Each Bluetooth device includes an SDP server application that manages the services records for each service available in the Piconet. Ultra wide band was first developed in the 1970s by the US military for low-power communication capable of evading mainstream eavesdropping techniques. UWB is an impulse RF system as opposed to a carrier-based RF. Carrier-based transmits data continuously while UWB transmit subnansecond pulses of energy, where the simplest modulation method assigns ones and zeros to the absence of pulses. UWB also uses a large part of the radio spectrum (3.1-10.6 GHz), not just a specific frequency or narrow frequency range, as is the case with FM, GPS, Bluetooth or 802.11 transmissions. Using this full band UWB can achieve data rates of upwards of 400 Mbps (short range ~10m). With such high speeds the first large


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market for UWB is predicted to be in home networking to provide links between computing devices, television, residential service gateway and other home appliances. The current proposed IEEE standard (802.15.3a) would limit this to 110Mbps over 10 meters or 480 Mbps over 1 meter. However due to competing industry concerns this standard has yet to be due to the concerns about the standards limitations. Regardless of such industry fights there are still a number of technical, social and legal hurdles to face. For example: the proposed bandwidth is currently unlicensed (similar to the ISM band), satellite-based telecommunication providers use the bandwidth, and certain countries such as Japan prohibit even UWB research due to interference-related concerns. While the need to connect home networks is clear, the case for wirelessly connecting devices using UWB for broadband content delivery has yet to be made. 4.8 MODALITIES AND MORE The applications in the future will typically take advantage of a combination of the input and output modalities on the devices that are currently available to a user. A typical scenario is for user to start a work task with device A (PDA) and B (Phone), then shift location to continue the task using device C (Laptop) before reverting to using just device A (PDA) to finish the task. Clearly, by moving between many devices during a work task we greatly expand the number of input and output modalities that can be used. These modalities typically include keyboard entry, pen entry, voice and gestural inputs and outputs such as print, screen, text-to-speech, and ambient displays. A later report from the Smart Internet will describe research, development and commercial opportunities for such multi-modal, multi-device and multi-user systems. A variety of programming languages are available for developing pervasive computing systems. While Java claims the write-once run-everywhere mantra, its reliance on a Java Virtual Machine limits its use on small, energy-conscious computing devices. Strides have been made to support Java on handheld devices such as PDAs and mobile phones using J2ME. However, the sacrifices made limit the functionality possible while native machine translations from languages such as C or C++ are more efficient and allow a greater range of device specific functionality to be accessed. The Geopriv scheme from the IETF is one of the first standards relating to context information for pervasive computing. It defines a privacy-centric approach for location information and services. The scheme involves creating digitally signed location objects that encapsulate user location data and associated privacy requirements. P3P, paws and Appel are designed to allow user agents to get the privacy practices from a web site in a wellunderstood language.


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CHAPTER 5 END USER APPLICATIONS Given the range of technologies described in Chapter 3, it is clear that there are a number of current end user applications that may be thought of as pervasive computing applications. However, if you consider that a truly pervasive computing application should make use of context data, then the range of end user applications narrows. As such, the following application areas can be considered prototypical of what is possible if a shift towards pervasive computing continues. 5.1 SMART SENSORS The mote system from UC Berkley (commercially available from Xbow) is a small computing platform that contains a battery, processor, memory, wireless networking and optional sensors about the size of a coin but ten times as thick. The mote has been deployed with TinyOS [60], a kernel with a minimal software footprint. The mote is the current generation for the realization of a DARPA funded project on “Smart Dust”. Smart dust is functionally similar to a mote but on order of µm scale. Each device will cost a faction of a cent and can be easily dispersed in the environment. Once dispersed the devices awake, form a network and start performing some distributed computing application (typically sensing the environment). Of all the technologies reported in this section, this is the furthest from realisation both conceptually and given many practical constraints such as environmental damage, form factor, power, noise, signal leakages etc. The mote system is in use in a number of environmental monitoring test-beds such as tracking bird migration and habits on a rural area to monitoring chemical pollutants across a wide city area. Smart-its are low small powered computing, sensing and communication devices that are especially designed for post hoc augmentation of everyday objects. They are similar to active RFID tags but include low rate wireless networking rather than the notion of communication using modulated signals (no readers required). Much of the research, for these devices has focused on minimizing power consumption by intelligent energy saving mechanisms. Researchers in the TecO group Karlsruhe have demonstrated an AwareCon network, which is aware of its situation and context of use. This approach allows greater energy saving and load distribution [61]. 5.2 SMART CARDS AND RFID Smart card applications typically include pre-paid phone cards, travel cards for public transit and loyalty points schemes. The cryptographic functions can be used to locally verify the identity of the user before allowing access to the data (eg. electronic cash). This decentralised scheme, which is used in the GeldKarte in Germany, allows digital cash to be loaded onto such cards, without the need for a connection back to a server system per transaction for authentication [71]. Some new car ignition systems contain a form of RFID reader that interrogates the RFID tag in the moulding of the key head, for extra security. Low-end tags contain one fixed preprogrammed unique data block, which is transmitted, to the reader when the chip receives energy, as described. These simple tags have no writeable storage and are typically used for unique product identification. High-end tags are typically powered as they must work at longer ranges and often contain more powerful processing and storage. The typical example of this is the car based electronic-toll system that can be found in Australia and across the world (EZPass, Speedpass, EToll). Unlike bar codes these devices do not require line of sight to operate, work at a longer range, do not require sorting, can store data and can be used for security. An area that is seeing widespread deployment of such passive and active tags is in freight


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industry. Take for example, the maritime transportation system in the USA which handles more than 7,500 ships annually which off-load 6 million truck-size containers. To address security concerns requirement, high-end RFID tags could periodically monitor electronic seals on the containers during transit. While the processes behind the schemes may be computerized, much of the checking, data entry and registry are still accomplished manually or via optical scanning systems. While such technologies may be advantages for parts of the supply chain, recent media attention has highlighted a primary consumer concern over the use of such passive devices, namely privacy. Unlike smart cards, these devices can be used without our knowledge or consent. Gillette, Firestone and Benetton have all described plans to use this technology for product tracking and supply chain management. “When the Italian clothing retailer Benetton planned to deploy RFID tags for some clothing lines, there was no mention in the press releases of the tag supplier, Philips Electronics, on how to disable the tags after the sale. There was a massive consumer reaction, which the press came to refer to as the Benetton Brouhaha. Because the modern passive RFID tag carries enough data bits to identify the individual garment and not just its type, consumers were concerned that the garments would be associated with the purchaser at the point of sale and added to a database. Then the tags would radiate identifying information to any tag reader anywhere, tracking their every movement.” Vince Stanford, IEEE Pervasive Computing, June 2003. In this case the supplier neglected to disclose that the tags would be password-protected prohibiting promiscuous responses to tag readers and would be rendered inoperative at the point of sale. This cautionary tale points to the need to consider consumer privacy first rather than blatant technology push. Christian religious groups have expressed concerns about this technology and its similarity to the “mark of the beast” as foretold in the Old Testament (Rev. 13:16–18). This similarity isn’t strained when you consider Applied Digital Solutions implantable VeriChip identity chip. Regardless of such concerns, this low cost technology will become ubiquitous for certain parts of business but not perhaps for the consumer. 5.3 HOME NETWORKS Current home networking solutions form a basic infrastructure for future home pervasive computing applications. First assume we have a home with a fixed (Ethernet, power line, phone line) or wired (802.11) home network, smart sensors, smart actuators, smart appliances and a residential service gateway installed. Many current homes have the light switches tied to specific lights, whereas with current switching technologies the light switches can be dynamically tied to any light without need for a direct electrical connection with the switch and the light it controls. When the switch is activated or touched it would send a message over the home network to switch on, off or dim accordingly (using CEBus for example [69]). Further, the home controller can learn particular patterns and can then implement specific behaviours. A simple rapid “on-off-on” for a particular switch can inform the system to put the lights into a preset lighting mood. The home controller can be told to run in holiday mode, to simulate the lighting patterns typically used each evening for security. The residential service gateway (controller) allows for a number of in home or remote services. An example of this is checking the on or off status of appliances remotely to provide security and peace of mind. Other examples include, devices requesting maintenance, downloading new operations or having entertainment applications follow the end user through different media devices in the home. 5.4 HOME MEDIA HUB There are an increasing number of competing technologies that aim to act as the “media hub” within the home. These devices can be broadly classed as personal recorders, set-top boxes, residential gateways and game consoles. As each device often contains functions of the other class, this categorisation is a very approximate and time-dependant.


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Personal recorders, while not prevalent outside of North America, are an important category in the media-hub domain. TiVo is the leading distributor of such devices, which record television programs onto a large hard disk into the device [64]. Software applications allow the user to navigate through stored television programs, set up preferences or set up the TiVos training suite. The training suite is used to learn a user model about the individual based on the viewing habits and preferences and then proactively record more programs than those requested. The concept is simple, if you like watching rugby, it will record as many rugby games as it can, so when you want to watch TV it will have a large cache of rugby games for you to choose from. Obviously broadcasters dislike this model as it allows advertisements to be skipped and alters viewing habits, thereby destroying the notion of prime time. Numerous lawsuits have been successfully defended but others are underway. It’s unlike TiVo will launch in Australia given the poor performance of the product launch in the UK. Set-top boxes act as a more mundane interface between the broadcasters of content of the consumer’s entertainment devices. They consist of a cable/phone or satellite tuner, followed by a module to decrypt the signal into audio/video and data, which is sent to various entertainment devices. These devices have been deployed in various forms for a number of years and are often used in conjunction with smart cards for authentication. Newer set-top boxes, such as those used by BSB in the UK, Canal+ in France and proposed for Digital FoxTel in Australia, include a return channel (cable, phone) from the set-top box for limited interactive functionality. Residential service gateways, such as that from Motorola, may include the functionality of a set-top box, along with support for Internet access (cable/phone), local wireless connection (802.11, Bluetooth), local DHCP and/or UPnP, application download, home device configuration, wireless keyboard, memory and hard disk. While the long-term goal is for open standards, the current and next generation of such devices is based on proprietary hardware, software and service agreements with Internet and content providers. The final class of device may form the greatest opportunity for SME hardware, software and service operators in Australia namely the game console. Game consoles such as the Sony Playstation 2 and Microsoft Xbox hold the lion’s share of the global home game console market. The game console typically includes an impressive graphics processor for rendering upwards of 125 million polygons per second. However, these devices are evolving into multifunctional entertainment systems with the inclusion of hard disk, networking support, fast processors, sound and memory. The majority of Playstation 2 buyers in Japan cite the built-in DVD drive as their main reason for buying the machine. Purchasers of the Xbox in Europe and Australia cite the ability to store their music collection on the device as a primary motivating factor. The next generation PlaystationX (PSX) from Sony will include a hard disk and many of the features listed as common to the residential service gateway [66]. The difficulty for console manufacturers is to recoup their costs, as the devices are rarely sold with a high profit margin and in some cases are sold below cost. The profits currently come from games sales but as this evolution continues, they will need to be recouped through the sale of services to the user. Services such as Xbox live are the first in a generation of such value add services for consumers. 5.5 MOBILE INFORMATION ACCESS AND GAMING DEVICES The Blackberry handheld device, while offering a niche service, does point towards what many pervasive computing research and development organizations hope will be future anywhere-anytime information services [75]. Over 500,000 people (alone or through corporations) have subscribed to a monthly service via their special-purpose handheld blackberry device, which allows them access to email and other textual information. Once the server system is installed into a client company, the remote device can provide a mobile email client. Further, the system operates on a push model so the encrypted email is delivered with a notification to the mobile client, instead of waiting for the user to pull or


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request new email. Note this model, akin to how SMS is delivered, is inherently different from a polling-pull model, which is typical of email usage on the desktop today. The blackberry device also offers built-in address book and calendar (which can be remotely synced). The novelty of this device comes from the combination of security, server-side software, handheld simple device and fixed-price subscription model. The system gained widespread fame in New York on September 11th 2001, as emails from blackberry subscribers got through while the mobile phone system collapsed to surging demand. It is worth noting that the success in North America may be due to socio-economic reasons including network coverage, former ubiquity of pager technology, basic mobile phone handsets, and the difficulty operating across mobile phone networks. The primary device in the handheld games device class is the Game-Boy although devices such as the N-gage from Nokia are blurring the line between a mobile phone and a games device [76]. As with the computation/service device this class of device does not form a substantive component of pervasive computing research and development, unless such devices incorporate wireless networking and expose their services to other devices. Any special purpose device that operates alone will not form part of a pervasive computing system due to the need for coordination and collaboration between devices. The N-gage illustrates an important point for pervasive computing researchers and developers, namely decoupling form, from function into a suite of devices may be better than attempting to create hybrid special purposes devices, that fulfil neither function well. The N-gage is a poor games device and a mobile phone with a poor form-factor and poor usability for making telephone calls. 5.6 MOBILE PHONE The current generation of mobile phone are powerful network clients with high-speed data transmission (GPRS), colour screens, personal information management applications, cameras and voice input. Since 2001 the number of mobile phones that can be classed as hybrid devices, due to their inclusion of PDA functionality have, increased. These devices, while bearing the form factor of a cellular phone, blur the line between phone, organizer and Internet access device. Piggybacking new functions onto a platform with high penetration and product turnover will see this confluence of technologies continue. Next generation “Smart Phones” with GPS, streaming data support (UMTS) and hard disks further blur the line between the telephone and other handheld computing devices [77]. However, this evolution may eventually hit a wall as the power, form factor, capacity, screen size and user interface issues limit the range of new applications possible. 5.7 PERSONAL DIGTIAL ASSISTANT The PDA was reborn in 1995 with the introduction of the Palm device from Palm Computing, which runs the Palm Operating System. The original Palm device had a grey scale screen, glyph-based character (graffiti) recognition, limited memory, a power efficient processor, infrared connection and serial connection to a PC. The device is intended for use in conjunction with a single PC for data synchronisation and application download. Palm, since subsumed into 3COM, saw a related spin-off in Handspring use its OS, only to later have Handspring spin back into Palm. Recent developments have seen Palm split into software (palmsource) and Hardware (palmOne) company. Along with PalmOS based devices from Sony, Samsung and Kyocera, Palm have developed numerous additions and refinements have since the original Palm I [78]. The major operating system for the PDA is Windows CE (Pocket PC) from Microsoft [79]. This operating system is intended to be an extension of the nearly ubiquitous Windows desktop computing interface. The goal is to provide a miniaturised PC by extending the consistent look and feel of common applications onto small computing devices with limited processing and form factor. This goal has drawn scorn from mobile computing researchers, interface purists and usability engineers. Windows CE devices require considerably more processing


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power and memory than their Palm equivalents due to the support for a larger OS, multimedia and games applications and various storage and wireless connectivity. Windows CE devices are typically loaded with a suite of management applications. Data can be reliably entered using a glyph based character set, free-form (script) text recognition, print characters or a virtual keyboard. A powerful synchronisation scheme, based on service managers and providers; resolves data conflicts, tracks changes and establishes connections via USB, infrared, serial or wireless connection as available. A service provider is an application plug-in that implements the application specific user interface and methods for data store. A web browser and media player provide access to cached or live content. The final operating system for handheld computers is Linux from the Open Source community. The porting of this operating system to these devices is an ad-hoc and bottomup community based effort. The porting activity typically has to deal with a broad range of Pocket PC devices based on PXA processors or StrongArm from Intel. The Linux source code is open source and as such can be freely tailored to any particular platform. However, this tailoring effort is typically arduous when the limitations of handheld computers are considered. Regardless, this effort is under way, and a number of stable distributions are available for a number of devices, typically in the Zaurus or iPAQ ranges. It’s not common for commercially available PDAs to come pre-installed with Linux but as with the desktop market, this will change. The simplicity of development is considerable, testing and development can occur on a Linux based desktop computer using a cross compiler before deployment on the handheld computer. 5.8 WEARABLE COMPUTERS The computing technology in wearable systems often takes the form of a laptop, PDA or other handheld computer. It is the display and interaction techniques that hold most interest for research. A common head-worn monocular display such as the SV-3 comes from MicroOptical [50]. This has VGA display with 640x480 resolution and a 16-degree horizontal field of view (19 degrees diagonal). In practice, the displayed image seems to float in space, overlaid on the real world. Because of a trick of the human eye, most users perceive “seeing through” the display even though it is opaque.


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CHAPTER 6 SUMMARY & CONCLUSION "Pervasive Computing allows for the convenient access, through a new class of appliances, to relevant information with the ability to easily take action on it when and where you need to." [22] A paradigm shift in human computing interaction, from single person single device scenarios, to multi person multi-device wireless computing is currently underway. This shift supports a more seamless interaction with future pervasive wireless networks, where both services and connectivity can be provided for personal and professional activities through a range and combination of mobile computing devices. It is envisaged that in the future people will be interacting within pervasive computing environments that consist of many input and output devices, sensors, computing devices, information services, controllers and actuators. The applications for the future “Smart Internet” typically take advantage of a combination of the input and output modalities on the devices that are currently available to a user. A typical scenario is for user to start a work task with device A (PDA) and B (Phone), then shift location to continue the task using device C (Laptop) before reverting to using just device A (PDA) to finish the task. Clearly, by moving between numbers of devices during a work task we greatly expand the number of input and output modalities that can be used. These modalities typically include keyboard entry, pen entry, voice and gestural inputs and outputs such as print, screen, text to speech and ambient displays. Projects within the Smart Internet Technology CRC are investigating methods for mediating the flow of control and data in smart applications using just such computing environments. Research in intelligent environments, pervasive computing, sentient computing, and ubiquitous computing is attempting to take the current context of the human activity into account with interacting with the user. Context includes information from the sensed environment (environmental state) and computational environment (computational state) that can be provided to alter applications behaviour. Or is an application state, which is of interest to the user.

“Context is any information that can be used to characterize the situation of an entity. An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and application themselves”. This context can take the form of your current location or simply just the capabilities of computer you are currently using. Broadly speaking this information comes from the sensed environment or the computational environment. Simply stated, any information that can be gleaned to alter an application’s behaviour is context. Specifically, context data includes spatial information (location, speed), identity (users and others in vicinity), user model (profile, preferences), temporal (time of day or year), environmental (noise, light), social (meeting, party), resources (printers, fax, wireless access), computing (network bandwidth, login), physiological (hearing, heart rate), activity (supervision, interview), schedules and agendas. Context-aware pervasive computing applications support the seamless interaction across a number of devices, to reduce the cognitive burden on the user by offering services that are adaptive, proactive or automatic. While pervasive computing describes a fundamentally different form of computing, it does in fact draw from a long history of research and development in areas including; distributed computing, mobile computing, human computer interaction and embedded systems. The major elements of pervasive computing have evolved from distributed systems, which first became a reality with the advent of local area networks. The distributed computing paradigm shift allowed for the decomposition of classically centralised computing problems into components that can be distributed across a set of interconnected machines. Such robust and high bandwidth networks in organizations are now common with various components such as Commercial-in-confidence

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file servers, print servers, web servers and application servers. The power of such distributed computing came from the simple middleware used to allow heterogeneous components to be integrated to perform various computational tasks. The next shift occurred as wide area networks and specifically the Internet emerged. Until the World Wide Web emerged in the early 1990s the majority of distributed computing across wide areas was limited to intra-organisation networks. With the WWW an explosion in distributed computing services and components occurred, to the point where today companies expose networked components that represent essential business processes or services that other organisations can glue together to form different services. For an example of this consider a web application that allows you to book a flight, hotel and car all from different companies. Although a number of middleware approaches are taken to manage the exposing and use of such services, the most recent addition is through the use of web services. In parallel to the development of global interconnected networks was the miniaturisation of technology and Moore’s law. These have seen the development of ever smaller and more portable computers and embedded computing devices along with sensors and actuators in our physical environment. The range of portable computers has emerged including the laptop, tablet, palmtop, PDA and mobile phone. However, despite what marketers tell us, no one of these devices will kill off all the others, due to application needs and the inherent human computer interaction problems each suffers from. These problems are due to issues resulting from small screens, keypad interfaces, navigation buttons, form-factor/size, and battery life. For example, editing a spreadsheet on a mobile phone, while possible, is difficult due to the limitations of the device. The evolution of wireless networking has led to the emergence of mobile computing. The range or wireless networking ranges from wide area networking to personal area networking. Mobile telephony operators, e.g. using GSM, typically offer wide area networks. Local wireless environments are common in offices and the home, e.g. using 802.11. While personal or peripheral computing interactions are accomplished using Bluetooth or IrDA. As with the range of portable computing solutions, this cornucopia of wireless technologies need to be used in conjunction with one another, as opposed to being seen as competing solutions. Finally, we reach pervasive or ubiquitous computing, which has been identified as an area for research and development since the early work of Weiser but has yet to realise its full potential [1]. Weiser and others’ central premise for this field is that invisible computers will be embedded in every day objects. And as such there will be hundreds of computing elements per person in our physical environment. Early Pervasive Computing work in Xerox Parc and EuroPARC included a digital desk project [82,83] (multi-camera, projector, tablet computer and normal desk interface), location-tracking system called “The Active Badge Location System" which allowed a system to track badges through a large environment [84], the ParcTab a system for ubiquitous information access [81] and Sotto Voce, a location aware e-guidebook. Research during the late 90’s in AT&T’s Research lab in Cambridge, UK saw the development of a local positioning system called the Active Bat system [7]. This is a widely cited pervasive computing system, as the basic positioning and wireless infrastructure allowed for a broad range of always-on, context-aware applications. This system consists of a controller, a fixed node receiver infrastructure and a number of active bat tags. The system operates using a combination of RF and ultrasound time-of-flight to estimate each tags location. Each tag emits an ultrasonic pulse directed to a matrix of receiving nodes mounted on the ceiling in each room as shown in Figure 4. The system collects the time each receiver measured the pulse and based on the speed of the sound waves determines the location. Although sensitive to the inter-node placement and a large receiver node infrastructure requirement, the system can achieve sub 10cm accuracy. The largest testbed developed consisted of 720 receivers and 6 radio cells covering an area of approximately 1000 m2 on


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three floors. In practice the system was able to determine the positions of up to 75 objects per second while being accurate to approximately 3cm in three dimensions [8]. Blis4 is an example of a commercial context-aware application by BluePosition in Denmark. This system enhances the “reachability” of the end-users of the systems by rerouting phone calls, allowing colleague location services and automatically locking terminals when unattended. An example deployment is in the Danish Parliament where the system automatically detects when a Member of Parliament or their personal assistant, enters Christiansborg Castle that houses the Danish Parliament. The system detects the MP or PA’s Bluetooth enabled mobile phone, and subsequently notifies a back office management systems, that interacts with a number of systems including Information Displays and the local PABX. When a MP enters the voting chamber the system updates the electronic voting system, the Information Displays, and instructs the GSM mobile network to forward all calls, thereby eliminating the disturbance of ringing mobile phones during sessions. This system has a number of end-user benefits including, automatic call diverting, single contact number per MP, less interruption and information screens to locate any MP. Other examples of context-aware systems include; UPS’s employee tracking system to optimise routing of collection and delivery times, NTT DoCoMo Japan, friends finder service where your location information is pushed to friends on a buddy list, when you are within half a kilometre, MOMA USA electronic museum guides that play different texts in different locations in the museum. One Pervasive Computing research and development project within the Smart Internet CRC is the patented BlueStar system [13]. BlueStar aims to provide indoor location context in a privacy centric manner, by deducing location from two sources of information on different levels of detail: •

Evidence from passive sniffing of existing wireless infrastructure (Bluetooth or 802.11b) or low cost beacons acting as access points

•

Details about the local wireless infrastructure, based on system knowledge of the user’s approximate location from a GSM’s network positioning system.

The novel aspect of this system allows for a network based system to allow only the end user to be aware of their accurate location while indoors, rather than an approach based on the system tracking the user. This approach addresses the major privacy issue by keeping the accurate location information under the user’s local control. The more privacy someone wants, the more abstract or redundant data that must be delivered to ensure the system cannot deduce where the person is. Further, by including a network centric approach to the delivery of the mapping, local information and local wireless network information, the proposed system can be deployed and tested on a large scale. The handset resident application communicates with only the BlueStar server across a GPRS connection. Once the handset resident location module makes its initial inquiry, the BlueStar server contacts the location gateway (typically an MPC) to determine the handsets approximately location. Rather than caching all mapping, information and wireless details the approximate location allows BlueStar to extract a smaller portion of the world model. This portion of the world model is delivered to the handset resident application and is still large enough to ensure the BlueStar system cannot micro-locate the end user. Pervasive Computing will develop as the expectation of what a computer and computing space evolves. Finally, we identify a number of possible developments that will help the evolution of Pervasive Computing. •

Privacy considerations: As pervasive computing research and developers may inadvertently develop tools for the ultimate societal monitoring system, privacy consideration must be factored in from the start and not applied in a post-hoc manner.


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•

Health and Defence: These are key areas for the uptake of Pervasive Computing systems, as many of the multi-user, multi-device, multi-modal scenarios can have immediate impact and benefit in these fields.

•

New computer operating systems: To support varying platforms with decoupled inputs and outputs, across the current available devices. Such systems will support the ad-hoc formation of personalised computing spaces, from the available devices and services, as required.

•

New economic models: For content distribution, content sharing, pricing, dissemination and rights management.

•

New pricing models for connectivity: Individuals many currently pay for a mobile phone, GPRS connection, broadband connection, home phone and office phone. Future devices may need to access one or more of these connections, some of which an individual doesn’t pay for directly but through a third-party or even a friend. For example, a future mobile phone may use any of these connections depending on availability and applicability.

•

New communication hardware: Work is underway for the development of software radios to support multiple communication paths (GSM, 802.11, Bluetooth) from a single communications chip as required.

•

New power management techniques: These will allow a great proliferation of small devices into the environment. This will be realized through novel power harvesting, fuel cells, capacitive stores, power management and transfer.

•

New Intelligent Applications: Based on the deployment of context-aware systems, applications need to become proactive and have the activity to match specific human activity to particular applications.

While the growth of basic mobile computing will continue, it will take new a view of services through the confluence of home, car, entertainment and business services in instrumented environments, to realise the pervasive computing vision. However, the limits of “human attention” don’t follow any growth pattern, as technologies tend to. The question is will it be possible for each person to interact with tens or hundreds of communicating computation elements in their environment? Early researchers noted that pervasive computing must be realised through “calm technologies”. A calm technology will move easily from the periphery of our attention, to the centre, and back. Consider for example, the usefulness of a power distribution grid; it comes not from its obvious nature but its invisibility, its reliability, its simplicity and the fact that power is part of life for people living in developed countries. This is the goal for Pervasive Computing, calm technologies that become part of life. “The most profound technologies are those that disappear, they weave themselves into the fabric of life until they are indistinguishable from it.” [1]


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SELECTED REFERENCES [1] [2] [3] [4] [5] [6] [7] [8]

[9] [10]

[11]

[12]

[13] [14] [15] [16] [17] [18] [19] [20]

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[21] Noi Sukaviriya, Mark Podlaseck, Rick Kjeldsen, Anthony Levas, Gopal Pingali, Claudio Pinhanez, Augmenting a Retail Environment Using Steerable Interactive Displays http://www.research.ibm.com/ed/publications/chi03b.pdf [22] http://www.research.ibm.com/compsci/spotlight/mobile/papers.html [23] Gopal Pingali, Claudio Pinhanez, Anthony Levas, Rick Kjeldsen, Mark Podlaseck, Han Chen, Noi Sukaviriya, “Steerable Interfaces for Pervasive Computing Spaces”, 1st IEEE International Conference on Pervasive Computing and Communications (PerCom'03), Dallas-Fort Worth, Texas, March 2003. http://www.cs.princeton.edu/~chenhan/papers/percom2003.pdf [24] Daniel M. Russell, Clemens Drews, Alison Sue, Social Aspects of Using Large Public Interactive Displays for Collaboration, http://www.almaden.ibm.com/software/user/BlueBoard/index.shtml [25] http://www.research.ibm.com/smartpad/ [26] http://www.intel.com/software/products/opensource/platform/osr.htm [27] JXTA a lightweight client-based system that supports ad hoc peer-to-peer messaging, key authentication, and distributed knowledge http://www.jxta.org/ [28] Groove is a shared spaces for documents, messages, and applications http://www.groove.net/ [29] W. Keith Edwards, Mark W. Newman, Jana Z. Sedivy, Trevor F Smith, Dirk Balfanz, D. K. Smetters, H. Chi Wong, Shahram Izadi. Using Speakeasy for Ad Hoc Peer-toPeer Collaboration. In Proceedings of CSCW '02. (November 2002) http://www2.parc.com/csl/projects/speakeasy/ [30] L. Gong, "Enclaves: Enabling Secure Collaboration over the Internet," IEEE J. Selected Areas in Communications, vol. 15, no. 3, Apr. 1997, pp. 567-575. [31] Roy Want, "The Personal Server - Changing the Way We Think about Ubiquitous Computing", Proceedings of Ubicomp 2002: 4th International Conference on Ubiquitous Computing, Springer LNCS 2498, Goteborg, Sweden, Sept 30th-Oct 2nd, 2002, pp194-209. http://www.intel.com/research/exploratory/personal_server.htm [32] Consolvo, S., Walker, M., "Using the Experience Sampling Method to Evaluate Ubicomp Applications," IEEE Pervasive Computing Mobile and Ubiquitous Systems: The Human Experience, Vol. 2, No. 2 (Apr-Jun 2003), pp. 24-31. http://seattleweb.intel-research.net/projects/ESM/ [33] A. Dey, R. Hamid, C. Beckmann, I. Li, and D. Hsu, "a CAPpella: Programming by Demonstration of Context-Aware Applications," Intel Research, IRB-TR-03-036, Oct. 7, 2003 [34] L. Barkhuus, and A. Dey, "Is Context-Aware Computing Taking Control Away from the User? Three Levels of Interactivity Examined," Proceedings of the Fifth Annual Conference on Ubiquitous Computing (UBICOMP 2003), Intel Research, IRB-TR-03008, May. 1, 2003 http://www.intel-research.net/berkeley/research_areas.asp [35] Dietz, P.H.; Leigh, D.L., "DiamondTouch: A Multi-User Touch Technology", ACM Symposium on User Interface Software and Technology (UIST), ISBN: 1-58113-438X, pps 219-226, November 2001 http://www.merl.com/projects/DiamondTouch/ [36] Stefik, M., Bobrow, D.G., Foster, G., Lanning, S., Tatar, D. WYSIWIS Revised: Early experiences with multi-user interfaces. ACM Transactions on Office Information Systems, 5:2, pp. 147-167, April 1987. (Reprinted in Baecker, R. Readings in Groupware and Computer Supported Cooperative Work, San Mateo: Morgan Kaufmann Inc., 1992). http://www2.parc.com/istl/members/stefik/colab.htm [37] Jun Rekimoto, SmartSkin: An Infrastructure for Freehand Manipulation on Interactive Surfaces, CHI2002, 2002 http://www.csl.sony.co.jp/person/rekimoto/smartskin/ [38] The interactive workspaces project: experiences with ubiquitous computing rooms. Johanson B, Fox A & Winograd T, Pervasive Computing 1(2):67-74, 2002. [39] Smart Personal Object Technology http://research.microsoft.com/spo/ [40] Paramvir Bahl and Venkata Padmanabhan. RADAR: An in-building RFbased user location and tracking system. In Proceedings of IEEE INFOCOM, volume 2, pages 775--784, March 2000. http://research.microsoft.com/locationawareness/


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[41] Brumitt, B., Krumm, J., Meyers, B., and Shafer, S. "Ubiquitous Computing and the Role of Geometry". IEEE Personal Communications, August 2000. http://research.microsoft.com/easyliving/ [42] Esler, M., Hightower, J., Anderson, T., and Borriello, G. Next Century Challenges: Data-Centric Networking for Invisible Computing: The Portolano Project at the University of Washington Mobicom 99. http://portolano.cs.washington.edu/ [43] David Graumann, Walter Lara, Jeffrey Hightower, and Gaetano Borriello, "Realworld implementation of the Location Stack: The Universal Location Framework," in Proceedings of the 5th IEEE Workshop on Mobile Computing Systems & Applications (WMCSA 2003), Oct. 2003. [44] Arnstein, L., Borriello, G., Consolvo, S., Hung, C., Su, J. Labscape: A Smart Environment for the Cell Biology Laboratory, IEEE Pervasive Computing Magazine, vol. 1, no. 3, July-September 2002, IEEE Computer Society, NY, NY http://labscape.cs.washington.edu/ [45] MIT Project Oxygen http://oxygen.lcs.mit.edu/ [46] N. Priyantha, A. Chakraborthy and H. Balakrishnan, “The Cricket Location-Support System”, Proceedings of International Conference on Mobile Computing and Networking, pp. 32-43, August 6-11, 2000, Boston, MA http://nms.lcs.mit.edu/projects/cricket [47] Kidd, Cory D., Robert J. Orr, Gregory D. Abowd, Christopher G. Atkeson, Irfan A. Essa, Blair MacIntyre, Elizabeth Mynatt, Thad E. Starner and Wendy Newstetter., "The Aware Home: A Living Laboratory for Ubiquitous Computing Research" In the Proceedings of the Second International Workshop on Cooperative Buildings http://www.cc.gatech.edu/fce/ahri/ [48] James J. Kistler and M. Satyanarayanan, "Disconnected operation in the coda file system." Proceedings of the thirteenth ACM symposium on operating systems principles, October 13-16, 1991, Pacific Grove, California. Pages 213-225. [49] Project Aura: toward distraction-free pervasive computing. Garlan D, Siewioek DP, Smailagic A & Steenkiste P, Pervasive Computing 1(2):22-31, 2002. http://www.computer.org/pervasive/pc2004/b1099.pdf [50] Micro Optical Corporation http://www.microopticalcorp.com/ [51] Salber, D., Dey, A. K., Orr, R. J., and Abowd, G. D. “The Context Toolkit: aiding the development of context-enabled applications”. In Proceedings of the 1999 Conference on Human Factors in Computing Systems, pages 434-441, Pittsburgh. [52] Mari Korkea-aho, Context-Aware Applications Survey, Department of Computer Science, Helsinki University of Technology, http://www.hut.fi/~mkorkeaa/doc/context-aware.html [53] Anind k. Dey, Understanding and Using Context . Personal and Ubiquitous Computing, Vol 5, Issue 1. 2001. [54] G. Chen and D. Kotz. A Survey of Context-Aware Mobile Computing Research. Technical Report, Dept. of Computer Science, Dartmouth College, Nov 2000 http://citeseer.nj.nec.com/390713.html [55] Ulf Leonhardt, “Supporting Location-Awareness in Open Distributed Systems”, PhD thesis, Department of Computing, Imperial College of Science, Technology and Medicine, University of London, May 1998. [56] Gellersen HW, Schmidt A & Beigl M, Multi-sensor context-awareness in mobile devices and smart artifacts. Mobile Networks and Applications 7(5):341-351, 2002 [57] Banavar G & Bernstein A, Software intrastructure and design challenges for ubiquitous computing applications. Communications of the ACM 45(12):92-96, 2002. [58] Helal S, Standards for service discovery and delivery. Pervasive Computing 1(3):95100, 2002. [59] Davies N, Cheverst K, Mitchell K & Efrat A, Using and determining location in a context-sensitive tour guide. IEEE Computer 34(8):35-41, 2001. [60] The Emergence of Networking Abstractions and Techniques in TinyOS, Philip Levis, Sam Madden, David Gay, Joe Polastre, Robert Szewczyk, Alec Woo, Eric Brewer and


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GLOSSARY OF TERMS 3G

Third generation wireless service with transmission speeds up to 2Mbps.

802.11a

Wireless LAN standard (WLAN) that uses the 5 GHz band and operates at a raw speed of 54 Mbit/s, and more realistic speeds in the mid-20 Mbit/s. Has not has not seen wide adoption

802.11b

WLAN standard that has a maximum throughput of 11 Mbit/s. In practice the maximum throughput is about 5.5 Mbit/s. 802.11b operates in the 2.4 GHz spectrum and uses Carrier Sense Multiple Access with Collision Avoidance.

802.11g

WLAN standard that uses the 2.4 GHz band like 802.11b, but operates at 54 Mbit/s raw or about 24.7 Mbit/s net. This standard is fully backwards compatible with b and is expected to dominate for WLAN access through 2007.

ADSL

Asymmetric Digital Subscriber Line (a form of DSL) is a standard where data can flow faster in one direction than the other, i.e., asymmetrically. Downstream rates range from 256 kbit/s to 9 Mbit/s, Upstream rates are from 64 to 256 kbit/s.

Ad-hoc network

A self-configuring network of mobile routers connected by wireless links, the union of which forms an arbitrary topology.

Applet

An application that has limited features, requires limited memory resources, and is usually portable across operating systems. Java Applets provide simple interactive on many web-pages.

Bluetooth

A protocol for short-range radio links between mobile computers, mobile phones, digital cameras, and other portable devices. Operates in the 2.4Ghx spectrum and has transmission at speeds up to 1Mbps within a radius of 30 feet (9.3 meters).

Byte Code

A binary file containing an executable program formed by a sequence of op code/data pairs.

CAN

Controller Area Network is a serial bus standard developed by Robert Bosch GmbH for connecting devices.

CDMA

A form of multiplexing where the transmitter encodes the signal using a pseudo-random sequence that the receiver also knows and can use to decode the received signal.

CORBA

An Object Management Group specification, which provides a standard messaging interface between, distributed objects.

DARPA

Defence Advanced Research Projects Agency is responsible for the development of new technology for use by the military

DES

A standard encryption algorithm that is a product cipher operating on 64-bit blocks of data, using a 56-bit key.

DHCP

Dynamic Host Configuration Protocol is a networking protocol, provides a means to allocate IP addresses dynamically to computers on a local area network.

Digital Signature

Extra data appended to a message that identifies and authenticates the sender and message data using public-key encryption.


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DSL

A family of digital telecommunications protocols designed to allow high-speed data communication over the existing copper telephone lines between end-users and telephone companies.

Firewire

IEEE 1394, A serial bus interface standard offering high-speed communications and isochronous real-time data services.

GEOS

A small windowing micro-kernel operating system, original designed for older PCs, now used on mobile-phone devices such as the Nokia Communicator 9000 and 9110.

GPRS

GSM data transmission technique that transmits and receives data in packets. Users pay by the volume of data transmitted.

GPS

A system of satellites, computers, and receivers that is able to determine the latitude and longitude of a receiver on Earth by calculating the time difference for signals from different satellites to reach the receiver.

GSM

Global system for mobile communications is currently used in the 900 MHz and 1800 MHz bands.

HDTV

High Definition Television typically embodied as a standard that has twice the standard number of scanning lines per frame and therefore produces pictures with greater detail.

IrDA data

IrDA Data is designed for infrared data transfer over a distance of up to 1 metre, acting as a point-to-point cable replacement.

ISP

A company that provides other companies or individuals with access to, or presence on, the Internet.

JVM

A Java Virtual Machine which interprets Java programs that have been compiled into byte-codes,

Jini

Sun's Java-based system for networking home appliances, desktop computers and other kinds of consumer electronics.

MP3

A digital audio algorithm that optimises the compression according to the range of sound that people can actually hear.

MPEG

A digital audio-visual compression standard aimed at broadcast quality video for applications such as digital television set-top boxes and DVD.

MMS

Multimedia Messaging System is a multimedia-enabled (digital photos, video) version of text-only SMS.

PDA

A small hand-held computer typically providing calendar, contacts, and note-taking applications but may include other applications, for example a web browser and media player

PIM

A personal information manager is a software application or suite that keeps track of personal information through functions such as, email, diary, calendar, to-do list and address book.

Private Key

Public-key cryptography, is a form of cryptography in which two digital keys are generated, one private and one public. The private key is for encrypting or signing messages.

Public Key

When a private key is used to encrypt a message then another public key is used to decrypt it. A private key (known only to the sender) is used to sign a message and another (known to everyone) is used to verify the signature.


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RFID

Radio frequency identification is a technology for remotely storing and retrieving data from "tags" attached to objects. Passive RFID tags obtain power generated by the radio waves to send a response, they typically can only be read.

RMI

RMI is an application-programming interface for performing remote procedural calls.

RTOS

Real Time Operating System is an operating system that has been developed for real-time applications.

Set-top box

A device used with a traditional television set to enable the reception and decoding of satellite, cable, or digital signals

SIM

Subscriber identity module is a smart card securely storing the key identifying a mobile subscriber. The card also contains storage space for SMS's and a phone book.

SMS

A buffered asynchronous message service offered by the GSM digital cellular telephone system. Short alphanumeric message.

TCP/IP

A protocol for communication between computers, used as a standard for transmitting data over networks and as the basis for standard Internet protocols.

Transcoding

At direct digital-to-digital conversion from one encoding scheme, such as MPEG-2, to a different encoding scheme such as AVI, without returning the signals to analogue form.

UWB

Ultra Wide Band transmits data at speeds between 40 to 60 megabits per second and eventually up to 1 gigabit per second. Uses ultra-low power radio signals with very short electrical pulses, often in the picosecond (1/1000th of a nanosecond) range, across all frequencies at once.

UMTS

Universal Mobile Telecommunications System is a standard for 3G mobile phone technologies. It uses W-CDMA as the underlying standard as standardized by the 3GPP.

UPnP

Universal Plug and Play, a networking architecture that provides compatibility among networking equipment, software and peripherals. UPnP offers device-driver independence and zero-configuration networking.

USB

Universal Serial Bus, an external bus standard that supports data transfer rates of 12 Mbps.

WAP

Wireless Application Protocol is an open international standard for applications that use wireless communication, for example Internet access from a mobile phone.


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