RoamHBA: maintaining group connectivity in sensor networks

This work presents a new group communication scheme, roamingcast, for collaborative information processing in wireless sensor networks. Roamingcast enables efficient communication among a subset of mobile terminals in a collaboration group. Unicast and multicast communication can be considered as special cases of roamingcast in which the subset contains one and all group members, respectively. We propose a Roaming Hub Based Architecture (RoamHBA, pronounced as 'rumba') as one solution to support roamingcast. We present the distributed construction and dynamic update of a multicast tree, referred as the roaming hub. This roaming hub has the property that an average pair of terminals communicate using the hub with only constant degradation in path length compared to the best possible path. We have developed network layer protocols implementing this mechanism and evaluated their performance in comparison with roaming restricted flooding. We simulated our design using NS-2.