A Survey of Adaptive Carrier Sensing Mechanisms for IEEE 802.11 Wireless Networks

Abstract

Abstract-This survey provides a comprehensive review of existing physical carrier sensing enhancements for IEEE 802.11 wireless networks. The original physical carrier sensing mechanism, used by wireless stations to gain access to the medium, is limited. Consequently, IEEE 802.11 networks are vulnerable to the presence of hidden and exposed nodes. Such nodes can significantly decrease system performance by increasing the collision rate and decreasing the channel spatial reuse. The value of the physical carrier sensing threshold is a key factor influencing the presence of hidden and exposed nodes in a wireless network. Several enhancements have been proposed in the literature, which attempt to mitigate the loss in performance caused by the limited carrier sensing. Firstly, the notion of an optimum carrier sensing threshold has been studied, and results indicate that it can be tuned to an optimum value. Building on the positive early results, further work was performed to develop mechanisms that dynamically adjust the threshold according to varying network conditions. This article presents an in-depth survey of the existing literature in the area, detailing the various approaches and their efficacy in addressing the problem of hidden and exposed nodes (and consequently increasing performance). It offers a comparison of the techniques, by evaluating the models, limitations, assumptions, and performance gains.

Evaluation of dynamic sensitivity control algorithm for IEEE 802.11ax

“…Considerable amount of work has been done to study how physical carrier sensing mechanism affects the capacity and throughput of IEEE 802.11 based WLANs [2], [3]. The motivation behind this work is to improve the efficiency of those networks so that requirements for increased capacity and higher performance could be fulfilled.…”

Optimized tuning of contention window for IEEE 802.11 WLAN

“…Moreover, if two or more stations attempt to send data packets at the same time, collision will happen and the packet is lost. In case of wireless networks, it is difficult to distinguish between collision of packets and external interference which leads to detecting collision highly complicated (Thorpe et al, 2014). But, the 802.11 standard defines the access mechanism of Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and offers the Distributed Coordination Function (DCF).…”

Joint Optimization of Carrier Sensing Threshold and Transmission Rate in Wireless Ad Hoc Networks

“…As surveyed in [1], the promising approaches can be divided into two categories, the temporal approach, mainly refers to the contention window adaptation, and the spatial approach or spatial reuse, including the carrier sensing threshold adaptation, the transmission rate adaptation, the transmission power control and the use of directional antenna. In recent years, there are many efforts focusing on the carrier sensing threshold adaptation [2]- [7] and transmission rate adaptation [8]- [10].…”