Performance analysis of IEEE 802.11ah wireless local area network under the restricted access window‐based mechanism

Summary IEEE 802.11ah is an approved amendment to IEEE 802.11 wireless local area network (WLAN) standard to support growing demand for machine‐to‐machine (M2M) applications. To enable an efficient scheme for accessing the channel by a large number of stations (STAs) within the coverage of an access point, 802.11ah has developed a novel mechanism known as Restrictred Access Window (RAW). Here, a group of STAs attempts channel access during their designated RAW slot by following the carrier sense multiple access‐collission avoidance (CSMA‐CA)‐based enhanced distributed channel access (EDCA) mechanism. In this paper, we develop an analytical model for finding the nonsaturation/saturation throughput of 802.11ah WLAN under the RAW‐based channel access mechanism. We describe an analytical model for finding the average frame delay as well. The impact of the number of STAs and number of groups on network throughput and average delay are presented. We establish that the RAW mechanism can improve the throughput while the average frame delay gets reduced. The analytical results are validated by extensive simulation studies. Restricted Access Window (RAW) is an efficient and novel mechanism adopted by 802.11ah for accessing the channel by a large number of stations (STAs) within the coverage of an access point. The analytical model in the paper for finding the nonsaturation/saturation throughput, average frame delay of 802.11ah and the impact of the number of STAs, and number of groups on network throughput establish that the RAW mechanism can improve the throughput significantly, while the average frame delay gets reduced.