Adaptive Multi-Channel Clustering in IEEE 802.11s Wireless Mesh Networks

Area of Science:

• Computer Science
• Wireless Networking
• Network Engineering

Background:

• Wireless Local Area Networks (WLAN) mesh networks are crucial for smart city applications due to flexible and cost-effective deployment.
• The IEEE 802.11s standard enables mesh interoperability at the MAC layer, but faces scalability challenges like traffic overhead and routing delays.
• Existing solutions suggest network partitioning into clusters using orthogonal channels to mitigate these issues.

Purpose of the Study:

• To introduce CHaChA (Clustering Heuristic and Channel Assignment), a distributed, cross-layer approach for cluster formation and channel assignment in IEEE 802.11s mesh networks.
• To ensure CHaChA's unrestricted compliance with the WLAN standard while integrating IEEE 802.11s mesh protocol information.
• To develop mechanisms for dynamic cluster adaptation, including joining, isolation, fault detection, and node roaming for improved network balancing.

Main Methods:

• Implemented a distributed, cross-layer algorithm (CHaChA) for cluster formation and channel assignment.
• Integrated CHaChA with the default IEEE 802.11s mesh protocol, leveraging its information and operating modes.
• Developed dynamic adaptation mechanisms: cluster joining, isolation, fault detection, and node roaming.
• Validated the approach through practical performance evaluation on a real-world 802.11s testbed.

Main Results:

• Demonstrated the practical performance of CHaChA in a real-world 802.11s testbed.
• Investigated clustering reproducibility, duration, and communication overhead in static network scenarios of varying sizes.
• Validated dynamic cluster adaptation mechanisms under realistic topology changes simulating long-term network operation.

Conclusions:

• CHaChA effectively addresses scalability limitations in IEEE 802.11s wireless mesh networks through distributed clustering and channel assignment.
• The approach maintains full compliance with the WLAN standard while offering dynamic adaptation capabilities for robust network operation.
• CHaChA shows practical viability for enhancing smart city applications relying on scalable and reliable wireless mesh infrastructure.