Design of MAC protocols with fast collision resolution for wireless local area networks

Abstract

Abstract-Development of efficient medium access control (MAC) protocols providing both high throughput performance for data traffic and good quality of service (QoS) support for real-time traffic is the current major focus in distributed contention-based MAC protocol research. In this paper, we propose an efficient contention resolution algorithm for wireless local area networks, namely, the fast collision resolution (FCR) algorithm. The MAC protocol with this new algorithm attempts to provide significantly higher throughput performance for data services than the IEEE 802.11 MAC algorithm and more advanced dynamic tuning backoff (DTB) algorithm. We demonstrate that this algorithm indeed resolves collisions faster and reduces the idle slots more effectively. To provide good fairness performance and to support good QoS for real-time traffic, we incorporate the self-clocked fair queueing algorithm and a priority scheme into the FCR algorithm and come up with the real-time FCR (RT-FCR) algorithm, and show that RT-FCR can simultaneously achieve high throughput and good fairness performance for nonreal-time traffic while maintaining satisfactory QoS support for real-time traffic.Index Terms-Backoff, IEEE 802.11, medium access control (MAC), quality of service (QoS), wireless local area networks (WLANs).

Survey of Real-Time Communication in CSMA-Based Networks

“…The finish tag is calculated similarly to the SCFQ (Self-Clocked Fair Queueing) algorithm [71]. In [72], the authors modify the distributed SCFQ algorithm combined with the prioritization schemes proposed in the EDCA mechanism and specify the RT-FCR (real-time fast collision resolution), where the priorities are implemented by assigning different backoff ranges based on the type of traffic.…”

B-EDCA: A New IEEE 802.11e-Based QoS Protocol for Multimedia Wireless Communications

“…The Fast Collision Resolution Mechanism FCR [7] aims to shorten the backoff period by increasing the contention window sizes of all active stations during the contention resolution period. To reduce the number of wasted (idle) slots, the FCR algorithm assigns the shortest window size and idle backoff timer to the station having successfully transmitted a packet.…”

“…Moreover, when a station detects a number of idle slots (static backoff threshold), it starts reducing the backoff timer exponentially, instead of linearly as specified by the EDCA draft standard. To address the provisioning of QoS mechanisms, the authors further introduce an enhanced version of the FCR algorithm, namely, the Real Time Fast Collision Resolution (RT-FCR) [7] algorithm. In this algorithm, the priorities are implemented by assigning different backoff ranges based on the type of traffic.…”

“…When choosing the parameter settings to use for the DCF and EDCA mechanisms under study, we have used the settings recommended by the standards [1], [2] (see Table I). The parameter settings used for the RT-FCR and AFEDCF mechanisms under study have been taken from references [7] and [9], respectively. The parameter settings for the B-EDCA mechanism have been defined by following the guidelines provided in Section 4.…”

A Cross Layer Time Slot Reservation Protocol for Wireless Networks

“…CSMA/CA uses backoff algorithm to avoid collision and reduce the collision probability in the wireless environment. Several backoff algorithms have been proposed to improve system performance [3], [4], however, the performance is still limited by the physical capacity due to the use of single shared channel. Therefore, it is necessary to improve the cross layer functions between the physical layer and MAC layer.…”