Title: Simultaneous Transmit and Receive Operation in Next Generation IEEE 802.11 WLANs: A MAC Protocol Design Approach,
Abstract: Full-duplex (FD) technology is likely to be adopted in various legacy
communications standards. The IEEE 802.11ax working group has been considering
a simultaneous transmit and receive (STR) mode for the next generation wireless
local area networks (WLANs). Enabling STR mode (FD communication mode) in
802.11 networks creates bi-directional FD (BFD) and uni-directional FD (UFD)
links. The key challenge is to integrate STR mode with minimal protocol
modifications, while considering the co-existence of FD and legacy half-duplex
(HD) stations (STAs) and backwards compatibility. This paper proposes a simple
and practical approach to enable STR mode in 802.11 networks with co-existing
FD and HD STAs. The protocol explicitly accounts for the peculiarities of FD
environments and backwards compatibility. Key aspects of the proposed solution
include FD capability discovery, handshake mechanism for channel access, node
selection for UFD transmission, adaptive acknowledgement (ACK) timeout for STAs
engaged in BFD or UFD transmission, and mitigation of contention unfairness.
Performance evaluation demonstrates the effectiveness of the proposed solution
in realizing the gains of FD technology for next generation WLANs.