Information communication scheme for loosely coupled mobile users in wireless sensor fields with multiple sources

In wireless sensor networks, groups of mobile users interested in equivalent information could be classified into two categories according to existence of direct communication channel among the users: 1) loosely coupled user group and 2) tightly coupled user group. The loosely coupled group means that a mobile user should communicate with others via a wireless sensor network for querying, gathering, and sharing of information interested from the group. Several information communication mechanisms have already been proposed to support mobility of the loosely coupled user groups. However, the mechanisms may not suit in case of sensor applications with multiple data sources since those are usually construct a network structure per each source. Namely, according to the mechanisms, too many network structures for the many data sources could be constructed and it may causes excessive computing overhead and energy exhaustion of sensors. Therefore, we propose an information communication mechanism to support mobility of loosely coupled mobile users in sensor applications with multiple sources. First, we examine the problems for mobility support of the loosely coupled groups in wireless sensor networks with multiple source nodes, and then study the dynamic sink communication model for data gathering from multiple sources and data delivery to a mobile user. Finally, we present an energyefficient solution to support mobility of loosely coupled groups based on data gathering tree establishment via distributed manner and tree-based data multicasting.