RMAC: Requirement Adaptive MAC for multi-hop wireless networks

The purpose of MAC (Medium Access and Control) schemes is to manage and control medium access of the given node such that the rate of successful transmission is maximised. The given problem is most challenging for multiple hop wireless networking scenarios. Mobility and ad hoc operational conditions further add to its complexity. Although prior research efforts have led to significant developments, the state-of-the-art is still found lacking in terms of channel utilisation achieved specially under dynamic network conditions. Random access based protocols are easy to deploy and operate. and are suitable for dynamic traffic and network conditions for low traffic and small network size. However, they do not scale well with the size of the network and perform poorly ill high traffic intensity scenarios. Throughput drops significantly with increase in the number of nodes or hops in the network. Schedule based protocols are suitable for large networks and high traffic intensity. But they do not perform well when they have to frequently update their schedules due to variation in traffic patterns and/or network topologies. Hybrid schemes provide good performances for some conditions. but even they fail to provide a universal solution. The aim of this research project is to develop a hybrid MAC scheme that combines strengths of random and schedule-based approaches, is flexible and scales well with network and traffic conditions. We achieved this by integrating requirement adaptivity into probabilistic STDMA approach using intelligent design choices to get RMAC (Requirement Adaptive MAC). We have shown, both through formal modelling and through simulations that in terms of channel utilization, RMAC significantly outperforms other contemporary MAC approaches.