IEEE Pervasive Computing

Changing the World

Nigel Davies of Lancaster University, UK presents his first introduction as editor in chief, and announces a series of changes to the magazine's editorial board. He summarizes the role of the magazine in the community and provides an overview of the editorial calendar for the coming year.

Gaming and Augmented Reality Come to Location-Based Services

Recently released mobile phone services include Foursquare and Gowalla, location-based social networking services with a gaming element, and Metro Paris Subway, Yelp, and Urbanspoon, which add augmented-reality features to local-search applications.

Wearable Displays—for Everyone!

Spectacles is a hardware/software platform developed from off-the-shelf components and ready for market. It includes local computation and communication facilities, an integrated power supply, and modular system building blocks such as sensors, voice-to-text and text-to-speech components, localization and positioning units, and microdisplay units. Its see-through display components are integrated into eyeglass frames.

Location-Based Services

Today, location information is in the hands of the masses. The success of location in pervasive computing has exposed new challenges and opportunities for researchers including making location sensing more robust, accurate, deployable, secure, and developer-friendly. This special issue showcases papers that describe recent research that addresses these challenges.

Location-Aware Tools for Improving Public Transit Usability

Real-time arrival information, immediately available on mobile devices, can significantly enhance the usability of public transit systems. The OneBusAway system provides just such information to more than 7,000 Seattle-area bus riders per day. The authors describe a new location-aware native iPhone application for OneBusAway that provides bus stop and arrival information tailored to the user's location. Results from survey and user-study evaluations demonstrate quicker access to data using the location-aware tool. In addition, data for OneBusAway users as a whole show strikingly positive changes in rider satisfaction, the number of transit trips per week, reduced wait time at bus stops, and increased walking. The positive results also hold for the location-aware version users, suggesting the possibility of even further gains.

How to Mitigate Signal Dragging during Wardriving

In wardriving, test devices in moving vehicles measure received signal strengths (RSSs) from nearby base stations (BSs) and record them with location information, which is a key component in localization technologies. In this article, the authors analyze the wardriving data in real WCDMA, GSM, and Wi-Fi networks and describe how signal dragging degrades their performance. They also propose three methods for postprocessing wardriving data to filter out any outdated BS information, thereby mitigating this effect.

LOC8: A Location Model and Extensible Framework for Programming with Location

Location is a core concept in most pervasive systems—and one that's surprisingly hard to deal with flexibly. Using a location model supporting a range of expressive representations for spaces, spatial relationships, and positioning systems, the authors constructed LOC8, a programming framework for exploring location data's multifaceted representations and uses. With LOC8, developers can construct complex queries by combining basic queries and additional contextual information.

Location and Navigation Support for Emergency Responders: A Survey

Emergency responders need location and navigation support, but few commercial or research localization systems are designed with them in mind. Harsh conditions and strict requirements make applying standard methods difficult. Preinstalled location systems, wireless sensor networks, and inertial sensing all have benefits and drawbacks when considering emergency response requirements. This survey of commercial products and research projects developed for such scenarios shows how these methods have been combined to address the concerns of firefighters and other indoor search-and-rescue personnel. In particular, a trade-off exists between easy deployment and good quality location support.

Human Activity Recognition and Pattern Discovery

Activity recognition and activity pattern discovery hold significant promise to enabling many applications in the domain of human behavior monitoring, understanding and alteration. However, concurrent, interleaved and highly similar activities challenge the utility of existing approaches. In this installment of the Standards and Emerging Technologies column we survey the state of the art and point to crucial limitations worthy of additional research and investigations.

Mobile Application Profiling for Connected Mobile Devices

The SymPA (Symbian Protocol Analyzer) tool correlates traffic information, radio-access-technology measurements, and location data to help developers evaluate mobile applications in the field.

Service Composition Issues in Pervasive Computing

Providing new services by combining existing ones—or service composition—is an idea pervading pervasive computing. Pervasive computing technologies seek to concurrently exhibit context awareness, manage contingencies, leverage device heterogeneity, and empower users. These four goals prompt service-composition-mechanism design requirements that are unique to pervasive computing. This article catalogs service composition mechanisms and describes their variation points, which indicate how well the resulting compositions meet the four goals.

A Low-Power, Battery-Free Tag for Body Sensor Networks

The authors describe a low-power, battery-free tag for use in pervasive sensing applications such as wearable patient-monitoring systems and body sensor networks. The tag consists of a custom integrated circuit, an antenna for RF energy harvesting, and several sensors for monitoring important physiological parameters and generating alarms when necessary. They also describe experimental results with phonocardiogram and photoplethysmogram signals and demonstrate tag localization within 0.6 m by using an audio localization scheme.

Eigenplaces: Segmenting Space through Digital Signatures

Unlike radio and television's unidirectional broadcast, wireless data network transceivers can act as probes to propagate environmental data back to a network observer. This fundamental difference lets researchers use the volume, timing, and distribution of packets passing across communications networks of varying scales to study the "bricks and mortar" of physical space. The authors use the Massachusetts Institute of Technology's Wi-Fi (IEEE 802.11) network to collect data generated as a by-product of network activity and correlate it with the physical environment using eigendecomposition.

Driving Automotive User Interface Research

Cars offer an interesting but challenging microcosm for pervasive computing research and, in particular, for interaction with pervasive computing systems. Increasingly, researchers are looking at interactive applications in the car and investigating human-car interaction from a computer science—rather than an ergonomics or mechanical engineering—perspective. This article reports on the International Conference on Automotive User Interfaces and Interactive Vehicular Applications, wherein participants shared presentations on topics such as aesthetics, user interaction and distraction, safety, and driver monitoring.