CHaChA: Clustering Heuristic and Channel Assignment for IEEE 802.11s Mesh Networks

Abstract

WLAN mesh networks are one of the key technologies for upcoming smart city applications and characterized by a flexible and low-cost deployment. The amendment IEEE 802.11s (.11s) introduces low-level mesh interoperability at the WLAN MAC layer. However, scalability limitations imposed by management traffic overhead, routing delays, medium contention, and interference are common issues in wireless mesh networks and also apply to. 11s networks. Possible solutions proposed in research recommend a divide-and-conquer scheme that partitions the network into clusters and forms smaller broadcast and collision domains by assigning different channels. We present CHaChA, a distributed cross-layer approach for clustering and channel assignment that directly integrates the default. 11s mesh protocol information and operation modes, retaining unrestricted compliance to the standard. The practical performance and implied benefits of CHaChA are demonstrated in a real-world testbed.