Adaptive Multi-Input Medium Access Control (AMI-MAC) Design Using Physical Layer Cognition for Tactical SDR Networks

Tactical software defined radio (SDR) networks demand stringent requirements of latency, throughput, and reliability. In the past, significant efforts have been made to achieve maximal efficiency with modifications and improvements either in an individual layer or through the cross-layer design of its working protocol. In this paper, we propose a novel cross-layer design consisting of adaptive multi-input medium access control (AMI-MAC) layer along with an intelligent channel allocation scheme supported by a multiband multimode physical layer. A cognitive engine further empowers this cross-layer design approach to achieve high throughput, improved quality of service (QoS), and adaptive range capabilities. The proposed physical layer exhibits a mixed use of narrowband and wideband waveforms accommodating different range requirements as per demanded QoS. The uniqueness of the proposed physical layer enables SDR to operate in hybrid topology by receiving multiple narrowband signals of different bandwidths with the same configuration of wideband RF front end. The proposed AMI-MAC design ensures a reduction in both control and data phase latency. MAC layer ensures the maximal utilization of the time and frequency spectrum. Bandwidth and delay optimization is also managed by the proposed trio of the physical layer, MAC, and cognition to reduce latency and achieve desired QoS. Simulation results are presented to show the superiority of the proposed design over conventional tactical radio MAC.