A generalized framework for throughput analysis in sparse mobile networks

Consider a mobile network wherein nodes are confined to move and communicate in a given area. The network is assumed to be sparse, wherein a direct communication path from a source node via multiple hops to a destination node almost never exists. The nodes resort to storing, carrying, and forwarding packets when a contact occurs, as a means of communication. This paper investigates the question of computing the throughput capacity of the resulting network, in other words, the rate at which a source node can send packets to a destination node using the other nodes in the network as relays. It proposes an accurate generalized framework valid for any mobility model that exhibits stationarity. The framework uses the embedded Markov-Chain approach using which the capacity of such a network can be accurately determined by computing certain well-defined characteristic parameters from the mobility model. Constraints posed by limited node storage and contention between nodes for the wireless channel are also considered in order to obtain a realistic model for the throughput. The paper also illustrates the proposed framework under two specific cases: the random walk, random waypoint, and restricted random waypoint mobility models, and validates the same using simulations.