Understanding the interaction between packet forwarding and channel access in multi-hop wireless networks

An analytical model is introduced for the study of the interplay between medium access control (MAC) and packet forwarding disciplines used in multi-hop wireless networks. The model incorporates the likelihood with which nodes access the channel, which is determined by the MAC protocol, and the creation of active portions of the topology, which is given by the packet forwarding discipline. The model allows the computation of per-node performance metrics for any given network topology and the combination of specific MAC protocols and packet forwarding methods. As an example of the applicability of our modeling framework, the analytical model is used to study the performance of multi-hop wireless networks using a contention-based MAC protocol (the IEEE 802.11 distributed coordination function) and a schedule-based MAC protocol (NAMA), together with different packet forwarding schemes in multi-hop networks. The analytical results derived from the model are validated with discrete-event simulations in Qualnet; the analytical results are shown to be very close to those attained by simulations.