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NOTE:The Center for Mobile Computing is now dormant, and this web site represents a historical view of its activities from 1996-2008. Although there is still mobile-computing research underway at Dartmouth, we no longer update the web site on a regular basis. Please contact Professor David Kotz with any inquiries about the CMC.

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What's New in the CMC? (2000-2001)

2002 and later...
December 2001... June 2001... March 2001... February 2001... August 2000... June 2000

December 2001

Versus Technology Joins CMC

Versus logo

We are pleased to have Versus Technology as a new Partner of the CMC. Their technology forms the cornerstone of the sensor information used our context-aware application research. Versus Technology, Inc. develops and sells leading-edge technology used for process improvement in the health care, security, government, and corporate markets. VIS (Versus Information System), a real-time locating system based on patented dual infrared and radio frequency technology, can be used to locate people and equipment, manage assets, and control access.

Location tracking in Sudikoff

In Sudikoff Lab, the home of the Department of Computer Science, electricians just installed a building-wide location-tracking system provided by Versus Technologies. The system allows us to track the location of asset tags attached to equipment, or badges attached to people, as they move about the building. The tags periodically emit an infrared (IR) (pulse, which is detected by a ceiling-mounted sensor. The system has one sensor per office, and a few sensors in larger labs and classrooms, so we can tell in which room a person or device is located. The sensors are all wired to a central collection system, which we will integrate into our Solar system so that applications can receive events about the location of people or devices of interest.

photo of badge photo of tag photo of IR sensor

As a back-up mechanism, the mobile badges also emit a periodic radio frequency (RF) pulse that can be detected by an RF sensor. In our building we need one IR sensor for each room, and a few RF sensors for the whole building. As a result, if the IR system is unable to detect a badge, perhaps because it is in a pocket or obscured by other objects, the system can at least know whether the badge is still in the building.

photo of RF sensor

Although we are intrigued by the approach in some of the prototype systems produced by research groups, such as the Cricket group at MIT, we chose Versus largely because it was able to provide a working system on a building-size scale, today, at a reasonable cost. (A typical Versus installation covers an entire hospital, to track staff and large mobile equipment.) We look forward to evaluating the success of an IR/RF approach to location tracking, and to the potential for using location data in applications.

Context-aware Mobile Computing

Much of our mobile-computing research here at Dartmouth strives toward the goal of ubiquitous computing. In this vision of the future, computers become an embedded part of our everyday environment, so ubiquitous in fact that they become almost invisible. This vision was perhaps best described by its early proponent, the late Marc Weiser of Xerox Parc. Applications for ubiquitous computing include location-aware services such as an appointment calendar that notifies you when it is time to start traveling to your next appointment, a to-do list that reminds you of errands when you are near an appropriate store or office, or a travel assistant that monitors your location, traffic and weather conditions, and airplane schedules to dynamically suggest alternatives or rearrange your schedule when conditions change. Smart meeting rooms might take notes (off the whiteboard or off attendees tablet computers), or make audio or video records. A telephony application rings the phone closest to the recipient, but only if they appear not to be in a meeting.

Applications of this sort are "context-aware" in the sense that they base their behavior on the context in which they execute. Context information includes the location of the user and of relevant devices, the computational capabilities of the users device(s) and the network, the presence of other people, the traffic or weather conditions, and so forth.

At Dartmouth, the Solar system project investigates these ideas.

June 2001

Recent graduates

Several students involved with the CMC received degrees this spring.

Other student news

Guanling Chen, Ph.D candidate

photo Guanling defended his thesis proposal in which he outlined his plans to develop the Solar system, an infrastructure that will provide context information to mobile context-aware applications. His innovative approach uses a network of "operator" objects to filter and transform data collected from sensors and distribute it to subscribing applications. He plans to complete his Ph.D. in 2003.

Springtime in the CMC

Wow, it's been a busy spring in the research labs of the Center for Mobile Computing! Dartmouth rolled out its new campus-wide wireless network, now 88% complete, covering nearly every academic, administrative, and residential building by an 11Mbps 802.11b network, using the latest access points from Cisco Systems. As Spring slowly arrived to melt the snow off the Hanover plain, we saw students lounging outside on the grass, surfing with their wireless laptop computers. Dartmouth is the first in the Ivy league with campus-wide wireless coverage, and doubtless recorded one of the fastest deployments (about 350 access points in two months).

Here at the CMC we immediately took advantage of this new network to enable several undergraduate research projects. Pablo Stern and Kobby Essien tracked the activity of every access point on campus, to capture a detailed picture of how the wireless network is used, who uses it, what they do with the network, and how they roam around campus. We'll repeat the study in the summer and fall when the network is more complete and more wireless devices are in place.

Dartmouth deployed its wireless access points in the existing building subnets, so a mobile user will switch subnets when roaming from building to building. Senior Ayorkor Mills-Tettey developed an extension to the H.323 telephony protocol that allows a voice-over-IP conversation to continue even when the mobile computer changes its IP address several times during the conversation. Senior Ammar Khalid developed a secure directory service to allow callers to initiate calls with mobile users, knowing only their name.

With wireless networking, computing devices become much more mobile. The CMC's "Solar" project aims to provide mobile applications information about their current context, such as location, so that they can adapt to the changing situation of their user. Ph.D. candidate Guanling Chen is developing the Solar infrastructure, and Senior Arun Mathias developed the first Solar application, a location-aware reminder program called SmartReminder.

The course on Computer Networks was excited to be a part of the action this Spring. In addition to the regular material, they were treated to a weekly seminar series on wireless networks and mobile computing. As a result several of their final projects were developed on Palm computers, and several took good advantage of IP multicast.

These are just a few of the exciting things that happened here this spring. You can find further details about the above projects in CMC papers, described within.

March 2001

Cisco donates wireless access points

Cisco's University Research Program has generously donated a set of Aironet 802.11 access points and PC cards for use in CMC research. We are excited by this opportunity and look forward to working with them. One of our first planned projects is to instrument the campus wireless network to gather information about how our population uses the network: what protocols do they use? what sorts of applications do they use? how often do they roam between base stations? between buildings? and so forth. Other projects involved voice-over IP, location-sensitive content, and context-aware applications.

Mitsubishi Electric Research Lab joins CMC

MERL is the US research laboratory for Mitsubishi Electric. Their charter is to conduct problem-driven basic research in computers and their uses, exploring entirely new categories of possibility rather than merely making incremental improvements to what is now possible. We look forward to working with them on fundamental challenges in mobile computing.

Nuance donates speech-recognition software

Nuance is a leading developer of speech-recognition software. Indeed, their technology is used in GM's OnStar network. In many mobile applications we believe that speech will be a more effective interface than keyboard or pen input, particularly in environments where the hands are busy elsewhere, such as when driving a car! Nuance has generously donated a license to their software for use in our teaching and research.

February 2001

Dartmouth announces installation of campus-wide wireless network!

August 2000

Large-scale wireless-networking lab

Research Engineer Bob Gray has assembled a large cluster of 50 Linux laptops, each with a WaveLAN Gold card (11 Mbps 802.11 wireless ethernet) and a GPS device. The cluster lives on several shelves in our lab, for development and testing, but will be taken out around campus for experiments involving wireless routing algorithms, mobile-agent applications, and so forth.

Apple donates iBooks, joins CMC

Apple Computer recently donated 10 iBooks with Airport wireless cards, an iMac DV, and an Airport base station. They are also the newest partner in the CMC. We are excited by the potential projects for these laptops and look forward to a fruitful partnership with Apple!

Microsoft Research donates Pocket PCs, joins CMC

Microsoft Research joined CMC recently, and also generously donated a dozen PocketPC and WindowsCE portables, several RangeLAN wireless devices, and books and software about Windows CE programming. We have been using the devices in several undergraduate projects.

Dartmouth professor Clayton Okino joins CMC

Clayton Okino is an assistant professor at the Thayer School of Engineering. His primary research interest is the performance of communication systems and wireless networks. Some of his current work focuses on statistical multiplexing schemes and smart sensor networks.

June 2000

Graduating students

Ph.D: Jon Howell, Brian Brewington
B.A.: Jay Artz, Debbie Chyi, Ned Holbrook, Flora Wan

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