A new modeling framework is introduced for the analytical study of medium access control (MAC) protocols operating in multihop ad hoc networks. The model takes into account the effect of physical-layer parameters on the success of transmissions, the MAC protocol on the likelihood that nodes can access the channnel, and the connectivity of nodes in the network. A key feature of the model is that nodes can be modeled individually, i.e., it allows a per-node setup of many layer-specific parameters. Moreover, no spatial probability distribution or a particular arrangement of nodes is assumed; the model allows the computation of individual (per-node) performance metrics for any given network topology and radio channel model. To show the applicability of the modeling framework, we model multihop ad hoc networks using the IEEE 802.11 distributed coordination function and validate the results from the model with discrete-event simulations in Qualnet. The results show that our model predicts results that are very close to those attained by simulations, and requires seconds to complete compared to several hours of simulation time.
['Marcelo M. Carvalho', 'Jose Joaquin Garcia-Luna-Aceves']
A scalable model for channel access protocols in multihop ad hoc networks