Multi-channel NOMA random access for inter-WBAN communication

To satisfy the increasing demand and heterogeneous QoS requirements of the wireless body area network (WBAN) traffic, with limited bandwidth resources, we propose the use of non-orthogonal multiple access (NOMA). The inter-WBAN uplink communication is proposed to be a multi-channel power domain NOMA random access, which allows each WBAN user to select an available channel randomly and select a power level from a set of pre-defined power levels according to specific rules. Dedicated channels are made available for the critical users, where the number of such dedicated channels is a decision variable of the proposed model. In order to maximize the throughput, a game theoretical technique is used for adjusting the retransmission probability. An analytical model is developed for deriving the throughput and packet delay. Numerical results are used to implement the channel reservation policy. Comparison of the proposed model with three existing models show that the proposed one significantly reduces the delays experienced by both the critical and the normal medical packets.