Design and Analysis of an Acknowledgment-Aware Asynchronous MPR MAC Protocol for Distributed WLANs

• Published in: IEEE transactions on wireless communications 2013-05, Vol.12 (5), p.2068-2079
• Main Authors: Mukhopadhyay, Arpan, Mehta, N. B., Srinivasan, V.
• Format: Article
• Language: English
• Subjects: Access control; Access methods and protocols, osi model; Analytical models; Applied sciences; Business and industry local networks; Channels; Cross-layer design; Delay; Delays; Exact sciences and technology; fixed-point analysis; Gain; IEEE 802.11; IEEE 802.11 Standards; Local area networks; Mathematical models; Media Access Protocol; medium access control; multi-packet reception; Multiaccess communication; Networks and services in france and abroad; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Teleprocessing networks. Isdn; Throughput; timer backoff; Timing devices; Transmission and modulation (techniques and equipments); Wireless communication; wireless local area network; Wireless networks
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2013.032513.120429

Multi-packet reception (MPR) promises significant throughput gains in wireless local area networks (WLANs) by allowing nodes to transmit even in the presence of ongoing transmissions in the medium. However, the medium access control (MAC) layer must now be redesigned to facilitate - rather than discourage - these overlapping transmissions. We investigate asynchronous MPR MAC protocols, which successfully accomplish this by controlling the node behavior based on the number of ongoing transmissions in the channel. The protocols use the backoff timer mechanism of the distributed coordination function, which makes them practically appealing. We first highlight a unique problem of acknowledgment delays, which arises in asynchronous MPR, and investigate a solution that modifies the medium access rules to reduce these delays and increase system throughput in the single receiver scenario. We develop a general renewal-theoretic fixed-point analysis that leads to expressions for the saturation throughput, packet dropping probability, and average head-of-line packet delay. We also model and analyze the practical scenario in which nodes may incorrectly estimate the number of ongoing transmissions.