In this demonstration, we present cellular phone applications developed on top of our middleware, and show the usefulness of the proposed group formation mechanism based on user’s context and group communication. Our middleware allows application programmers to efficiently develop cooperative applications consisting of a large number of cell phone terminals. To cope with several restrictions of cellular phones, our middleware allows application software to be executed separately on a server and user terminals. Group communication is implemented as interprocess communication on the server, and only the userinterface parts are executed on the cellular phones.

In this paper, we propose a middleware library for efficiently developing distributed cooperative applications consisting of a large number of cellular phone users. Our middleware provides: (1) a dynamic group formation mechanism depending on users' locations and preferred subjects; and (2) a group communication mechanism called multiway synchronization for multicasting, synchronization and mutual exclusion. Most of Java executors on cellular phones do not support direct communication among user programs. Usable resources are also restricted. Therefore, in our middleware, most of user programs are executed on their servers as agents. Group communication is implemented as inter-process communication on the server, and only the user-interface parts are executed on the cellular phones.