Controlling Concurrency in Mobile Computing Environments with Broadcast-Based Data Dissemination

Abstract

A wireless broadcast environment is defined as a mobile computing environment in which data are delivered to mobile clients by means of a broadcast-based mechanism. Of course, those applications have to see the most recent consistent database state. For that reason, in such a scenario, database servers should synchronize operations for ensuring data consistency and currency of data. However, conventional serializability-based concurrency control protocols are unsuitable for synchronizing transactions in broadcast environments. The major goal of this work is to present a new serializability-based protocol to synchronize transactions in data intensive applications. The proposed protocol saves battery power, since it ensures that mobile clients do not have to contact servers (for requiring locks, for example) to access data. Thus, mobile clients do not need to listen to the broadcast continuously; they listen to the broadcast channel to retrieve data they need. Therefore, the proposed protocol supports client disconnections. We performed simulation analysis to evaluate the performance of the new protocol. The simulation results show that the proposed protocol offers better performance than others protocols.