Time-Triggered Reservation for Cooperative Random Access in Wireless LANs

In this paper, a novel time-triggered reservation scheme is proposed to improve the performance of IEEE 802.11 medium access control (MAC) protocol. The proposed Reservation-based Distributed Channel Access (RDCA) protocol leverages the overhearing feature of the shared wireless channel and allows reservation-based data transmission with collision resolution. The reservation is realized in a time-triggered manner by setting extra timers on mobile stations. Through time-triggered reservation, a collision-free transmission scheduling can be achieved in a collaborative way without the assistance from the access point (AP). RDCA substantially reduces the delay and can function as the MAC layer for the wireless extension of time-sensitive networking (TSN). Meanwhile, the throughput of the network is increased due to the reduction of collisions. Moreover, RDCA also maintains backward compatibility with the legacy IEEE 802.11 terminals. The analysis of saturated throughput is provided and the performance gain in terms of delay and throughput is evaluated by extensive simulations. Compared to legacy IEEE 802.11, the throughput in RDCA increases up to 50% and the delay reduces up to 70%.