A Station Grouping Method Considering Heterogeneous Traffic and Multiple Data Rates for IEEE 802.11ah Networks with Non-uniform Station Deployment

Abstract

In IoT networks, mitigation of channel access contention is one of the crucial requirements due to a massive number of devices connecting to the shared communication channel. In order to satisfy this requirement, IEEE 802.11ah introduces the restricted access window (RAW) mechanism which divides wireless stations (STAs) into several STA groups and allocates a dedicated RAW slot to each STA group. Since STA grouping plays an important role in this mechanism, several grouping methods have been proposed. However, the IoT networks have various network non-uniformity such as in STA deployment and so on. Although the existing method can deal only with the non-uniformity of STA deployment, traffic patterns and data rates at STAs may also vary due to various communication services provided in the real IoT networks. This paper proposes a STA grouping method which can handle not only non-uniform STA deployment, but also heterogeneous traffic patterns and multiple data rates at STAs. The performance for the proposed method is evaluated through computer simulation to show that the proposed method can improve the network performance even when STAs with various traffic patterns and data rates are deployed non-uniformly.