Multi-round transmission and contention protocol in WLANs with multi-packet reception

Nowadays, there are many scenarios in Wi-Fi networks where many devices compete for network access via an Access Point to transmit their information. Thus, the ability to separate multiple packets sent simultaneously using advanced digital processing techniques in the physical layer, known as Multi-Packet Reception (MPR), has become crucial. As this feature may increase network throughput, medium access control (MAC) protocols that efficiently exploit the MPR capability have been investigated. This paper proposes a new MAC protocol that exploits the MPR capability in 802.11 RTS/CTS access mechanism networks. It is based on the use of multiple contention and transmission rounds. In this sense, the MPR MAC protocol schedules several transmission periods once the contention phase finishes. Multiple transmission rounds reduce the overhead and substantially increase throughput. The analytical expressions that support the proposed approach are derived and verified by simulation. The results show that the proposed MAC protocol can yield close to 94% of the ideal performance using only four transmission rounds, compared with 80% of the previous approaches in the literature.