Scheduling Mobile Nodes for Cooperative Data Transport in Sensor Networks

Message ferrying has been shown to be an effective approach to support routing in sparse ad hoc or sensor networks. Considering a generic network model where each node in the network wishes to send data to some (or possibly all) other nodes with known (and possibly different) rates, we propose three schemes enabling multiple ferries to coordinate in collecting and delivering the data. We analyze the performance of each scheme and establish bounds on the average and worst-case delay. The latter bounds are useful in offering performance guarantees. We establish that under one of our schemes, constant per-node throughput is achievable within constant maximum (worst-case) delay as the network size grows. Using simulation, we compare our proposed schemes with an alternative, the Ferry Relaying algorithm proposed earlier in the literature. The results show that our schemes perform better and provide guidance on which scheme to use given performance preferences and the number of available ferries.