On The Capacity Deficit of Mobile Wireless Ad Hoc Networks: A Rate Distortion Formulation

Overheads incurred by routing protocols diminish the capacity available for relaying useful data in a mobile wireless ad hoc network. Discovering lower bounds on the amount of protocol overhead incurred for routing data packets is important for the development of efficient routing protocols, and for characterizing the actual (effective) capacity available for network users. This paper presents an information-theoretic framework for characterizing the minimum routing overheads of geographic routing in a network with mobile nodes. specifically, the minimum overhead problem is formulated as a rate-distortion problem. The formulation may be applied to networks with arbitrary traffic arrival and location service schemes. Lower bounds are derived for the minimum overheads incurred for maintaining the location of destination nodes and consistent neighborhood information in terms of node mobility and packet arrival process. This leads to a characterization of the deficit caused by the routing overheads on the overall transport capacity. Index Terms Wireless Ad Hoc Networks, Geographic Routing, Routing Overheads, Capacity Deficit, Rate-Distortion Theory