Modeling and computing throughput capacity of wireless multihop networks

Capacity is an important property for QoS support in Mobile Ad Hoc Networks (MANETs) and has been extensively studied. However, most approaches rely on simplified models (e.g., protocol interference, unidirectional links, perfect scheduling or perfect routing) and either provide asymptotic bounds or are based on integer linear programming solvers. In this paper, we present a probabilistic approach to capacity calculation by linking the normalized throughput of a communicating pair in an ad hoc network to the connection probability of the two nodes in a so-called schedule graph G(T)(N, E). The effective throughput of a random network is modeled as a random variable and its expected value is computed using Monte-Carlo methods. A schedule graph G(T)(N, E) for a given network is directly derived from the physical properties of the network like node distribution, radio propagation and channel assignment. The modularity of the approach leads to a capacity analysis under more realistic network models. In the paper, throughput capacity is computed for various forms of network configurations and the results are compared to simulation results obtained with ns-2. (C) 2007 Elsevier B.V. All rights reserved.