Comparison between Aloha and CSMA in multiple hop ad hoc networks
Résumé
Study of Mobile Ad hoc Networks is a very up-to-date topic. A lot of research studies have been carried out with a special emphasis on routing protocols. In the meantime access protocols designed for multihop ad hoc networks receive less consideration. While in wired network the benefit of carrier sensing has been shown to be very significant , in multihop ad hoc networks this benefit can be questionnable since hidden collisions are known to significantly degrade performance of CSMA (Carrier Sense Multiple Access) protocols . Using a simple but realistic model, we compare the global throughput of CSMA protocols and Aloha in mulihop ad hoc networks. To maintain this comparison, we assume an isotropic progation without obstacles and network nodes locations following a Poisson process. We compare results of this model with simulations. We show that, actually, carrier sensing improves the global throughput. This result could be thought to be in contradiction with a previous study . The reason of this apparent contradiction is explained.