| A Quantitative Method for Revealing and Comparing Places in the Home | | BIBA | Full-Text | 1-18 | |
| Ryan Aipperspach; Tye Rattenbury; Allison Woodruff; John Canny | |||
| Increasing availability of sensor-based location traces for individuals, combined with the goal of better understanding user context, has resulted in a recent emphasis on algorithms for automatically extracting users' significant places from location data. Place-finding can be characterized by two sub-problems, (1) finding significant locations, and (2) assigning semantic labels to those locations (the problem of "moving from location to place") [8]. Existing algorithms focus on the first sub-problem and on finding city-level locations. We use a principled approach in adapting Gaussian Mixture Models (GMMs) to provide a first solution for finding significant places within the home, based on the first set of long-term, precise location data collected from several homes. We also present a novel metric for quantifying the similarity between places, which has the potential to assign semantic labels to places by comparing them to a library of known places. We discuss several implications of these new techniques for the design of Ubicomp systems. | |||
| Principles of Smart Home Control | | BIBA | Full-Text | 19-34 | |
| Scott Davidoff; Min Kyung Lee; Charles Yiu; John Zimmerman; Anind K. Dey | |||
| Seeking to be sensitive to users, smart home researchers have focused on the concept of control. They attempt to allow users to gain control over their lives by framing the problem as one of end-user programming. But families are not users as we typically conceive them, and a large body of ethnographic research shows how their activities and routines do not map well to programming tasks. End-user programming ultimately provides control of devices. But families want more control of their lives. In this paper, we explore this disconnect. Using grounded contextual fieldwork with dual-income families, we describe the control that families want, and suggest seven design principles that will help end-user programming systems deliver that control. | |||
| Historical Analysis: Using the Past to Design the Future | | BIBA | Full-Text | 35-51 | |
| Susan Wyche; Phoebe Sengers; Rebecca E. Grinter | |||
| Ubicomp developers are increasingly borrowing from other disciplines, such as anthropology and creative design, to inform their design process. In this paper, we demonstrate that the discipline of history similarly has much to offer ubicomp research. Specifically, we describe a historically-grounded approach to designing ubicomp systems and applications for the home. We present findings from a study examining aging and housework that demonstrate how our approach can be useful to sensitize ubicomp developers to the impact of cultural values on household technology, to reunderstand the home space, and to spur development of new design spaces. Our findings suggest that historically-grounded research approaches may be useful in more deeply understanding and designing for context both in and outside of the home. | |||
| Extending Authoring Tools for Location-Aware Applications with an Infrastructure Visualization Layer | | BIBA | Full-Text | 52-68 | |
| Leif Oppermann; Gregor Broll; Mauricio Capra; Steve Benford | |||
| In current authoring tools for location-aware applications the designer typically places trigger zones onto a map of the target environment and associates these with events and media assets. However, studies of deployed experiences have shown that the characteristics of the usually invisible ubiquitous computing infrastructure, especially limited coverage and accuracy, have a major impact on an experience. We propose a new approach in which designers work with three layers of information: information about the physical world, information about digital media, but also visualizations of ubiquitous infrastructure. We describe the implementation of a prototype authoring tool that embodies this approach and describe how it has been used to author a location-based game for mobile phones called Tycoon. We then outline the key challenges involved in generalizing this approach to more powerful authoring tools including acquiring and visualizing infrastructure data, acquiring map data, and flexibly specifying how digital content relates to both of these. | |||
| Automated Generation of Basic Custom Sensor-Based Embedded Computing Systems Guided by End-User Optimization Criteria | | BIBA | Full-Text | 69-86 | |
| Susan Lysecky; Frank Vahid | |||
| We describe a set of fixed-function and programmable blocks, eBlocks, previously developed to provide non-programming, non-electronics experts the ability to construct and customize basic embedded computing systems. We present a novel and powerful tool that, combined with these building blocks, enables end-users to automatically generate an optimized physical implementation derived from a virtual system function description. Furthermore, the tool allows the end-user to specify optimization criteria and constraint libraries that guide the tool in generating a suitable physical implementation, without requiring the end-user to have prior programming or electronics experience. We summarize experiments illustrating the ability of the tool to generate physical implementations corresponding to various end-user defined goals. The tool enables end-users having little or no electronics or programming experience to build useful customized basic sensor-based computing systems from existing low-cost building blocks. | |||
| An Experimental Comparison of Physical Mobile Interaction Techniques: Touching, Pointing and Scanning | | BIBA | Full-Text | 87-104 | |
| Enrico Rukzio; Karin Leichtenstern; Vic Callaghan; Paul Holleis; Albrecht Schmidt; Jeannette Chin | |||
| This paper presents an analysis, implementation and evaluation of the physical mobile interaction techniques touching, pointing and scanning. Based on this we have formulated guidelines that show in which context which interaction technique is preferred by the user. Our main goal was to identify typical situations and scenarios in which the different techniques might be useful or not. In support of these aims we have developed and evaluated, within a user study, a low-fidelity and a high-fidelity prototype to assess scanning, pointing and touching interaction techniques within different contexts. Other work has shown that mobile devices can act as universal remote controls for interaction with smart objects but, to date, there has been no research which has analyzed when a given mobile interaction technique should be used. In this research we analyze the appropriateness of three interaction techniques as selection techniques in smart environments. | |||
| An Exploratory Study of How Older Women Use Mobile Phones | | BIBAK | Full-Text | 105-122 | |
| Sri Kurniawan | |||
| This paper reports on issues related to the use of mobile phones by women
aged 60 years and over. The study started with a series of focus group
discussions, which covered usage patterns, problems, benefits, ideal phone
design, and desired and unwanted features. It then moved to an exploration of
the group's cooperative learning process when encountering an unfamiliar mobile
phone. The issues raised in the discussions were translated into an online
questionnaire, which was responded to by 67 women aged 60 and over. This study
makes two main contributions to the field. First, it is one of a very few
studies that provides a diagrammatic representation of older mobile phone
female users' cooperative learning process and strategies. Second, the study
presents a combination of quantitative and qualitative data, which provides
more nuanced interpretation and understanding of the use of mobile phones by
older women. Keywords: Elderly; mobile phone; older adults; focus group; questionnaire | |||
| Farther Than You May Think: An Empirical Investigation of the Proximity of Users to Their Mobile Phones | | BIBA | Full-Text | 123-140 | |
| Shwetak N. Patel; Julie A. Kientz; Gillian R. Hayes; Sooraj Bhat; Gregory D. Abowd | |||
| Implicit in much research and application development for mobile phones is the assumption that the mobile phone is a suitable proxy for its owner's location. We report an in-depth empirical investigation of this assumption in which we measured proximity of the phone to its owner over several weeks of continual observation. Our findings, summarizing results over 16 different subjects of a variety of ages and occupations, establish baseline statistics for the proximity relationship in a typical US metropolitan market. Supplemental interviews help us to establish reasons why the phone and owner are separated, leading to guidelines for developing mobile phone applications that can be smart with respect to the proximity assumption. We show it is possible to predict the proximity relationship with 86% confidence using simple parameters of the phone, such as current cell ID, current date and time, signal status, charger status and ring/vibrate mode. | |||
| No More SMS from Jesus: Ubicomp, Religion and Techno-spiritual Practices | | BIBA | Full-Text | 141-158 | |
| Genevieve Bell | |||
| Over the last decade, new information and communication technologies have lived a secret life. For individuals and institutions around the world, this constellation of mobile phones, personal computers, the internet, software, games, and other computing objects have supported a complex set of religious and spiritual needs. In this paper, I offer a survey of emerging and emergent techno-spiritual practices, and the anxieties surrounding their uptake. I am interested in particular in the ways in which religious uses of technology represent not only a critique of dominant visions of technology's futures, but also suggest a very different path(s) for ubiquitous computing's technology envisioning and development. | |||
| Scribe4Me: Evaluating a Mobile Sound Transcription Tool for the Deaf | | BIBA | Full-Text | 159-176 | |
| Tara Matthews; Scott Carter; Carol Pai; Janette Fong; Jennifer Mankoff | |||
| People who are deaf or hard-of-hearing may have challenges communicating with others via spoken words and may have challenges being aware of audio events in their environments. This is especially true in public places, which may not have accessible ways of communicating announcements and other audio events. In this paper, we present the design and evaluation of a mobile sound transcription tool for the deaf and hard-of-hearing. Our tool, Scribe4Me, is designed to improve awareness of sound-based information in any location. When a button is pushed on the tool, a transcription of the last 30 seconds of sound is given to the user in a text message. Transcriptions include dialog and descriptions of environmental sounds. We describe a 2-week field study of an exploratory prototype, which shows that our approach is feasible, highlights particular contexts in which it is useful, and provides information about what should be contained in transcriptions. | |||
| SenseCam: A Retrospective Memory Aid | | BIBA | Full-Text | 177-193 | |
| Steve Hodges; Lyndsay Williams; Emma Berry; Shahram Izadi; James Srinivasan; Alex Butler; Gavin Smyth; Narinder Kapur; Ken Wood | |||
| This paper presents a novel ubiquitous computing device, the SenseCam, a sensor augmented wearable stills camera. SenseCam is designed to capture a digital record of the wearer's day, by recording a series of images and capturing a log of sensor data. We believe that reviewing this information will help the wearer recollect aspects of earlier experiences that have subsequently been forgotten, and thereby form a powerful retrospective memory aid. In this paper we review existing work on memory aids and conclude that there is scope for an improved device. We then report on the design of SenseCam in some detail for the first time. We explain the details of a first in-depth user study of this device, a 12-month clinical trial with a patient suffering from amnesia. The results of this initial evaluation are extremely promising; periodic review of images of events recorded by SenseCam results in significant recall of those events by the patient, which was previously impossible. We end the paper with a discussion of future work, including the application of SenseCam to a wider audience, such as those with neurodegenerative conditions such as Alzheimer's disease. | |||
| Development of a Privacy Addendum for Open Source Licenses: Value Sensitive Design in Industry | | BIBA | Full-Text | 194-211 | |
| Batya Friedman; Ian Smith; Peter H., Jr. Kahn; Sunny Consolvo; Jaina Selawski | |||
| Drawing on Value Sensitive Design, we developed a workable privacy addendum for an open source software license that not only covers intellectual property rights while allowing software developers to modify the software (the usual scope of an open source license), but also addresses end-user privacy. One central innovation of our work entails the integration of an informed consent model and a threat model for developing privacy protections for ubiquitous location aware systems. We utilized technology that provided a device's location information in real-time: Intel's POLS, a "sister" system to Intel's Place Lab. In January 2006, POLS was released under a license combining the substantive terms of the Eclipse Public License together with this privacy addendum. In this paper, we describe how we developed the privacy addendum, present legal terms, and discuss characteristics of our design methods and results that have implications for protecting privacy in ubiquitous information systems released in open source. | |||
| Mobility Detection Using Everyday GSM Traces | | BIBA | Full-Text | 212-224 | |
| Timothy Sohn; Alex Varshavsky; Anthony LaMarca; Mike Y. Chen; Tanzeem Choudhury; Ian Smith; Sunny Consolvo; Jeffrey Hightower; William G. Griswold; Eyal de Lara | |||
| Recognition of everyday physical activities is difficult due to the challenges of building informative, yet unobtrusive sensors. The most widely deployed and used mobile computing device today is the mobile phone, which presents an obvious candidate for recognizing activities. This paper explores how coarse-grained GSM data from mobile phones can be used to recognize high-level properties of user mobility, and daily step count. We demonstrate that even without knowledge of observed cell tower locations, we can recognize mobility modes that are useful for several application domains. Our mobility detection system was evaluated with GSM traces from the everyday lives of three data collectors over a period of one month, yielding an overall average accuracy of 85%, and a daily step count number that reasonably approximates the numbers determined by several commercial pedometers. | |||
| Practical Metropolitan-Scale Positioning for GSM Phones | | BIBA | Full-Text | 225-242 | |
| Mike Y. Chen; Timothy Sohn; Dmitri Chmelev; Dirk Haehnel; Jeffrey Hightower; Jeff Hughes; Anthony LaMarca; Fred Potter; Ian Smith; Alex Varshavsky | |||
| This paper examines the positioning accuracy of a GSM beacon-based location system in a metropolitan environment. We explore five factors effecting positioning accuracy: location algorithm choice, scan set size, simultaneous use of cells from different providers, training and testing on different devices, and calibration data density. We collected a 208-hour, 4350Km driving trace of three different GSM networks covering the Seattle metropolitan area. We show a median error of 94m in downtown and 196m in residential areas using a single GSM network and the best algorithm for each area. Estimating location using multiple providers' cells reduces median error to 65-134 meters and 95% error to 163m in the downtown area, which meets the accuracy requirements for E911. We also show that a small 60-hour calibration drive is sufficient for enabling a metropolitan area similar to Seattle. | |||
| Predestination: Inferring Destinations from Partial Trajectories | | BIBA | Full-Text | 243-260 | |
| John Krumm; Eric Horvitz | |||
| We describe a method called Predestination that uses a history of a driver's destinations, along with data about driving behaviors, to predict where a driver is going as a trip progresses. Driving behaviors include types of destinations, driving efficiency, and trip times. Beyond considering previously visited destinations, Predestination leverages an open-world modeling methodology that considers the likelihood of users visiting previously unobserved locations based on trends in the data and on the background properties of locations. This allows our algorithm to smoothly transition between "out of the box" with no training data to more fully trained with increasing numbers of observations. Multiple components of the analysis are fused via Bayesian inference to produce a probabilistic map of destinations. Our algorithm was trained and tested on hold-out data drawn from a database of GPS driving data gathered from 169 different subjects who drove 7,335 different trips. | |||
| Fish'n'Steps: Encouraging Physical Activity with an Interactive Computer Game | | BIBA | Full-Text | 261-278 | |
| James J. Lin; Lena Mamykina; Silvia Lindtner; Gregory Delajoux; Henry B. Strub | |||
| A sedentary lifestyle is a contributing factor to chronic diseases, and it is often correlated with obesity. To promote an increase in physical activity, we created a social computer game, Fish'n'Steps, which links a player's daily foot step count to the growth and activity of an animated virtual character, a fish in a fish tank. As further encouragement, some of the players' fish tanks included other players' fish, thereby creating an environment of both cooperation and competition. In a fourteen-week study with nineteen participants, the game served as a catalyst for promoting exercise and for improving game players' attitudes towards physical activity. Furthermore, although most player's enthusiasm in the game decreased after the game's first two weeks, analyzing the results using Prochaska's Transtheoretical Model of Behavioral Change suggests that individuals had, by that time, established new routines that led to healthier patterns of physical activity in their daily lives. Lessons learned from this study underscore the value of such games to encourage rather than provide negative reinforcement, especially when individuals are not meeting their own expectations, to foster long-term behavioral change. | |||
| Hitchers: Designing for Cellular Positioning | | BIBAK | Full-Text | 279-296 | |
| Adam Drozd; Steve Benford; Nick Tandavanitj; Michael Wright; Alan Chamberlain | |||
| Hitchers is a game for mobile phones that exploits cellular positioning to
support location-based play. Players create digital hitch hikers, giving them
names, destinations and questions to ask other players, and then drop them into
their current phone cell. Players then search their current cell for hitchers,
pick them up, answer their questions, carry them to new locations and drop them
again, providing location-labels as hint to where they can be found. In this
way, hitchers pass from player to player, phone to phone and cell to cell,
gathering information and encouraging players to label cells with meaningful
place names. A formative study of Hitchers played by 47 players over 4 months
shows how the seams in cellular positioning, including varying cell size,
density and overlap, affected the experience. Building on previous discussions
of designing for uncertainty and seamful design, we consider five ways of
dealing with these seams: removing, hiding, managing, revealing and exploiting
them. This leads us to propose the mechanism of a dynamic search focus, to
explore new visualization tools for cellular data, and to reconsider the
general relationship between 'virtual' and 'physical' worlds in location-based
games. Keywords: Mobile games; cellular positioning; ubiquitous computing; seamful design | |||
| Embedding Behavior Modification Strategies into a Consumer Electronic Device: A Case Study | | BIBA | Full-Text | 297-314 | |
| Jason Nawyn; Stephen S. Intille; Kent Larson | |||
| Ubiquitous computing technologies create new opportunities for preventive healthcare researchers to deploy behavior modification strategies outside of clinical settings. In this paper, we describe how strategies for motivating behavior change might be embedded within usage patterns of a typical electronic device. This interaction model differs substantially from prior approaches to behavioral modification such as CD-ROMs: sensor-enabled technology can drive interventions that are timelier, tailored, subtle, and even fun. To explore these ideas, we developed a prototype system namedViTo. On one level, ViTo functions as a universal remote control for a home entertainment system. The interface of this device, however, is designed in such a way that it may unobtrusively promote a reduction in the user's television viewing while encouraging an increase in the frequency and quantity of non-sedentary activities. The design of ViTo demonstrates how a variety of behavioral science strategies for motivating behavior change can be carefully woven into the operation of a common consumer electronic device. Results of an exploratory evaluation of a single participant using the system in an instrumented home facility are presented. | |||
| Instrumenting the City: Developing Methods for Observing and Understanding the Digital Cityscape | | BIBA | Full-Text | 315-332 | |
| Eamonn O'Neill; Vassilis Kostakos; Tim Kindberg; Ava Fatah gen. Schiek; Alan Penn; Danaë Stanton Fraser; Tim Jones | |||
| We approach the design of ubiquitous computing systems in the urban environment as integral to urban design. To understand the city as a system encompassing physical and digital forms and their relationships with people's behaviours, we are developing, applying and refining methods of observing, recording, modelling and analysing the city, physically, digitally and socially. We draw on established methods used in the space syntax approach to urban design. Here we describe how we have combined scanning for discoverable Bluetooth devices with two such methods, gatecounts and static snapshots. We report our experiences in developing, field testing and refining these augmented methods. We present initial findings on the Bluetooth landscape in a city in terms of patterns of Bluetooth presence and Bluetooth naming practices. | |||
| Voting with Your Feet: An Investigative Study of the Relationship Between Place Visit Behavior and Preference | | BIBA | Full-Text | 333-350 | |
| Jon Froehlich; Mike Y. Chen; Ian E. Smith; Fred Potter | |||
| Real world recommendation systems, personalized mobile search, and online city guides could all benefit from data on personal place preferences. However, collecting explicit rating data of locations as users travel from place to place is impractical. This paper investigates the relationship between explicit place ratings and implicit aspects of travel behavior such as visit frequency and travel time. We conducted a four-week study with 16 participants using a novel sensor-based experience sampling tool, called My Experience (Me), which we developed for mobile phones. Over the course of the study Me was used to collect 3,458 in-situ questionnaires on 1,981 place visits. Our results show that, first, sensor-triggered experience sampling is a useful methodology for collecting targeted information in situ. Second, despite the complexities underlying travel routines and visit behavior, there exist positive correlations between place preference and automatically detectable features like visit frequency and travel time. And, third, we found that when combined, visit frequency and travel time result in stronger correlations with place rating than when measured individually. Finally, we found no significant difference in place ratings due to the presence of others. | |||
| Lo-Fi Matchmaking: A Study of Social Pairing for Backpackers | | BIBA | Full-Text | 351-368 | |
| Jeff Axup; Stephen Viller; Ian MacColl; Roslyn Cooper | |||
| It is technically feasible for mobile social software such as pairing or 'matchmaking' systems to introduce people to others and assist information exchange. However, little is known about the social structure of many mobile communities or why they would want such pairing systems. While engaged in other work determining requirements for a mobile travel assistant we saw a potentially useful application for a pairing system to facilitate the exchange of travel information between backpackers. To explore this area, we designed two studies involving usage of a low-fidelity role prototype of a social pairing system for backpackers. Backpackers rated the utility of different pairing types, and provided feedback on the social implications of being paired based on travel histories. Practical usage of the social network pairing activity and the implications of broader societal usage are discussed. | |||
| Experiences from Real-World Deployment of Context-Aware Technologies in a Hospital Environment | | BIBA | Full-Text | 369-386 | |
| Jakob E. Bardram; Thomas R. Hansen; Martin Mogensen; Mads Soegaard | |||
| Context-aware computing is a central concept in ubiquitous computing and many suggestions for context-aware technologies and applications have been proposed. There is, however, little evidence on how these concepts and technologies play out in a real-world setting. In this paper we describe and discuss our experiences from an ongoing deployment of a suite of context-aware technologies and applications in a hospital environment, including a context-awareness infrastructure, a location tracking system, and two context-aware applications running on interactive wall displays and mobile phones. Based on an analysis of the use of these systems, we observe that many of the ideas behind context-aware computing are valid, and that the context-aware applications are useful for clinicians in their work. By reflecting on the nature of the designed context-aware technologies, we present a model which states that the triggering of context-awareness actions depend upon the accuracy of the sensed context information, the degree to which you know which action to perform in a given situation, and the consequence of performing the action. | |||
| Doing Community: Co-construction of Meaning and Use with Interactive Information Kiosks | | BIBA | Full-Text | 387-403 | |
| Tom Hope; Masahiro Hamasaki; Yutaka Matsuo; Yoshiyuki Nakamura; Noriyuki Fujimura; Takuichi Nishimura | |||
| One of the challenges for ubiquitous computing is to design systems that can be both understood by their users and at the same time understand the users themselves. As information and its meaning becomes more associated with the communities that provide and use it, how will it be possible to build effective systems for these users? We have been examining these issues via ethnographic analysis of the information and community supporting system that we have developed and employed at conference events. This paper presents initial analysis and suggests greater focus on the interaction between members of micro-communities of users in future ubicomp research. | |||
| Moving on from Weiser's Vision of Calm Computing: Engaging UbiComp Experiences | | BIBAK | Full-Text | 404-421 | |
| Yvonne Rogers | |||
| A motivation behind much UbiComp research has been to make our lives
convenient, comfortable and informed, following in the footsteps of Weiser's
calm computing vision. Three themes that have dominated are context awareness,
ambient intelligence and monitoring/tracking. While these avenues of research
have been fruitful their accomplishments do not match up to anything like
Weiser's world. This paper discusses why this is so and argues that is time for
a change of direction in the field. An alternative agenda is outlined that
focuses on engaging rather than calming people. Humans are very resourceful at
exploiting their environments and extending their capabilities using existing
strategies and tools. I describe how pervasive technologies can be added to the
mix, outlining three areas of practice where there is much potential for
professionals and laypeople alike to combine, adapt and use them in creative
and constructive ways. Keywords: calm computing; Weiser; user experiences; engaged living; UbiComp history;
pervasive technologies; proactive computing | |||
| Ferret: RFID Localization for Pervasive Multimedia | | BIBA | Full-Text | 422-440 | |
| Xiaotao Liu; Mark D. Corner; Prashant Shenoy | |||
| The pervasive nature of multimedia recording devices enables novel pervasive multimedia applications with automatic, inexpensive, and ubiquitous identification and locationing abilities. We present the design and implementation of Ferret, a scalable system for locating nomadic objects augmented with RFID tags and displaying them to a user in real-time. We present two alternative algorithms for refining a postulation of an object's location using a stream of noisy readings from an RFID reader: an online algorithm for real-time use on a mobile device, and an offline algorithm for use in post-processing applications. We also present methods for detecting when nomadic objects move and how to reset the algorithms to restart the refinement process. An experimental evaluation of the Ferret prototype shows that (i) Ferret can refine object locations to only 1% of the reader's coverage region in less than 2 minutes with small error rate (2.22%); (ii) Ferret can detect nomadic objects with 100% accuracy when the nomadic distances exceed 20cm; and (iii) Ferret works with a variety of user mobility patterns. | |||
| PowerLine Positioning: A Practical Sub-Room-Level Indoor Location System for Domestic Use | | BIBA | Full-Text | 441-458 | |
| Shwetak N. Patel; Khai N. Truong; Gregory D. Abowd | |||
| Using existing communications infrastructure, such as 802.11 and GSM, researchers have demonstrated effective indoor localization. Inspired by these previous approaches, and recognizing some limitations of relying on infrastructure users do not control, we present an indoor location system that uses an even more ubiquitous domestic infrastructure -- the residential powerline. PowerLine Positioning (PLP) is an inexpensive technique that uses fingerprinting of multiple tones transmitted along the powerline to achieve sub-room-level localization. We describe the basics behind PLP and demonstrate how it compares favorably to other fingerprinting techniques. | |||
| UbiREAL: Realistic Smartspace Simulator for Systematic Testing | | BIBA | Full-Text | 459-476 | |
| Hiroshi Nishikawa; Shinya Yamamoto; Morihiko Tamai; Kouji Nishigaki; Tomoya Kitani; Naoki Shibata; Keiichi Yasumoto; Minoru Ito | |||
| In this paper, we propose a simulator for facilitating reliable and inexpensive development of ubiquitous applications where each application software controls a lot of information appliances based on the state of external environment, user's contexts and preferences. The proposed simulator realistically reproduces behavior of application software on virtual devices in a virtual 3D space. For this purpose, the simulator provides functions to facilitate deployment of virtual devices in a 3D space, simulates communication among the devices from MAC level to application level, and reproduces the change of physical quantities (e.g., temperature) caused by devices (e.g., air conditioners). Also, we keep software portability between virtual devices and real devices. As the most prominent function of the simulator, we provide a systematic and visual testing method for testing whether a given application software satisfies specified requirements. | |||
| Instant Matchmaking: Simple and Secure Integrated Ubiquitous Computing Environments | | BIBA | Full-Text | 477-494 | |
| D. K. Smetters; Dirk Balfanz; Glenn Durfee; Trevor F. Smith; Kyung-Hee Lee | |||
| Effective ubiquitous computing applications need to integrate users' personal devices and data with the devices and resources they encounter around them. Previous work addressed this problem by simply enabling the user to take all of their data with them wherever they go. In this paper, we present a more flexible approach: the "instant matchmaker", a personal device that allows a user to seamlessly and securely connect his local computing environment with his other personal resources, wherever they are. The matchmaker provides an intuitive user experience, while simultaneously enabling extremely fine-grained control over access to resources. We have implemented a cellphone-based matchmaker and explored its use in a secure media sharing application. The matchmaker concept, however, is general, and can be used to enable a range of appealing and secure ubicomp applications. | |||
| A Wirelessly-Powered Platform for Sensing and Computation | | BIBA | Full-Text | 495-506 | |
| Joshua R. Smith; Alanson P. Sample; Pauline S. Powledge; Sumit Roy; Alexander Mamishev | |||
| We present WISP, a wireless, battery-free platform for sensing and computation that is powered and read by a standards compliant Ultra-High Frequency (UHF) RFID reader. To the reader, the WISP appears to be an ordinary RFID tag. The WISP platform includes a general-purpose programmable flash microcontroller and implements the bi-directional communication primitives required by the Electronic Product Code (EPC) RFID standard, which allows it to communicate arbitrary sensor data via an EPC RFID reader by dynamically changing the ID it presents to the reader. For each 64 bit "packet," the WISP's microcontroller dynamically computes the 16-bit CRC that the EPC standard requires of valid packets. Because the WISP device can control all bits of the presented ID, 64 bits of sensor data can be communicated with a single RFID read event. As an example of the system in operation, we present 13 hours of continuous-valued light-level data measured by the device. All the measurements were made using power harvested from the RFID reader. No battery, and no wired connections (for either power or data) were used. As far as we are aware, this paper reports the first fully programmable computing platform that can operate using power transmitted from a long-range (UHF) RFID reader and communicate arbitrary, multi-bit data in response to a single RFID reader poll event. | |||
| Automated Application-Specific Tuning of Parameterized Sensor-Based Embedded System Building Blocks | | BIBA | Full-Text | 507-524 | |
| Susan Lysecky; Frank Vahid | |||
| We previously developed building blocks to enable end-users to construct customized sensor-based embedded systems to help monitor and control a users' environment. Because design objectives, like battery lifetime, reliability, and responsiveness, vary across applications, these building blocks have software-configurable parameters that control features like operating voltage, frequency, and communication baud rate. The parameters enable the same blocks to be used in diverse applications, in turn enabling mass-produced and hence low-cost blocks. However, tuning block parameters to an application is hard. We thus present an automated approach, wherein an end-user simply defines objectives using an intuitive graphical method, and our tool automatically tunes the parameter values to those objectives. The automated tuning improved satisfaction of design objectives, compared to a default general-purpose block configuration, by 40% on average, and by as much as 80%. The tuning required only 10-20 minutes of end-user time for each application. | |||