A New Design for QoS Support in Full-Duplex IoT Networks

Wireless full-duplex (FD) communication offers substantial gains in spectral efficiency; however, it introduces significant interference challenges, particularly in densely deployed Internet of Things (IoT) networks. While existing FD MAC protocols often concentrate on partial FD scenarios involving access points (APs) and half-duplex (HD) nodes, or treat interference mitigation and Quality of Service (QoS) provisioning as separate objectives, this paper presents an Interference-and-Demand-Aware FD MAC protocol (IDA-FDMAC) tailored for fully FD networks where both the AP and nodes possess FD capabilities. IDA-FDMAC features a novel two-stage contention mechanism that integrates dynamic priorities informed by node QoS requirements (uplink/downlink dominance) and prevailing interference conditions. The protocol employs modified RTS/CTS frames to disseminate QoS information and utilizes signature-based contention resolution to minimize packet collisions. Comparative simulation results demonstrate that IDA-FDMAC achieves considerably higher throughput compared to conventional CSMA/CA and existing interference-aware FD protocols, while effectively delivering differentiated QoS according to node demands.