The Mobile Project
The description below is rather outdated. The pages for the Continuum project are more up-to-date.
- Background and Motivation (outdated)
- Status (outdated)
- Research Directions(outdated)
- The Continuum Project
- An Adaptation Network Infrastructure(outdated)
- A “Geographic Web” Prototype(outdated)
- Case Study: Making Cartographic Information Available to a Mobile User (outdated)
- An architecture for secure, client-driven deployment of application-specic proxies(outdated)
- Performance of TCP handoffs in a mobile environment(outdated)
- Publications (outdated)
Background and Motivation
Wireless and mobile environments bring different challenges to users and service providers when compared to fixed, wired networks. Physical constraints become much more important, such as device weight, battery power, screen size, portability, quality of radio transmission, error rates. Mobility brings additional uncertainties, as well as opportunities to provide new services and supplementary information to users in the locations where they find themselves. In general, most application software, operating systems, and network infrastructures are intended for more conventional environments, and so the mobile, wireless user has great difficulty exploiting the computational infrastructure as fully as he or she might. There is an emerging consensus among researchers that a new architecture and dynamic infrastructure is an appropriate way to address this problem.
As the Internet becomes ever more pervasive, and wireless access to it becomes more common, there will be a growing need for middleware that can mediate among the several parties involved. Infrastructure providers can provide location-based information to subscribers and service providers; they can also exploit aggregate and individual location information to better manage their own communication infrastructure. Mobile ISPs can provide value-added services that enhance the user’s awareness of services in the environment, and provide means of interacting with those services. Users perceive a rich, adaptive electronic infrastructure that presents the entire Internet to them in a convenient, controllable, dynamic way.
In our research into making this future environment a practical reality, we have found it useful to “divide and conquer” the problem into five categories: content;user services, and adaptive applications;user services, and adaptive applications;profiles and control interfaces; network and location services.
The top layer consists of application software and information, corresponding roughly to the current Internet. In order to provide users with an adaptive and dynamic environment, they and/or the applications they use employ middleware to sense the environment and request special support services, making use of user profiles and control interfaces to them. This middleware relies on network and location services as a basis for communication. Our research attempts to understand how to build upon the current internet architecture to incorporate mobile users and devices, and to assist the users, applications, and service providers in providing a dynamic, adaptive computational infrastructure.
We have made a number of contributions in each of the categories. We have several sample programs that adapt their presentation of MPEG media to the capacity of the wireless link; we are also working on accessing web-based information about the immediate vicinity of the user, and on an adaptive map browser. We have a mature infrastructure called Comma that provides instrumentation of and feedback about the environment to client and server-based software. We have built a number of proxy and support services, ranging from performance improvements to TCP, to mobile-object toolkits, to secure deployment of third-party proxy software. We have yet to explore general provision of user profiles and control interfaces, but have built some simple control interfaces for our proxy and service software.