Multiple Access Control for Cognitive Radio-Based IEEE 802.11ah Networks.

Area of Science:

• Wireless Communication
• Internet of Things (IoT)
• Cognitive Radio (CR)

Background:

• Radio spectrum scarcity due to IoT proliferation in Industrial, Scientific, and Medical (ISM) bands.
• Cognitive Radio (CR) offers efficient spectrum use for IoT, but faces challenges like the Hidden Primary Terminal (HPT) problem.
• Existing IEEE 802.11af and 802.11ah systems require centralized control and incur significant overhead for managing IoT device groups.

Purpose of the Study:

• To propose a novel Multiple Access Control (MAC) protocol for CR-based IEEE 802.11ah systems.
• To address collisions and interference issues in CR-based IoT environments.
• To reduce signaling overhead associated with managing device groups in dynamic IoT networks.

Main Methods:

• Introduction of the Restricted Access with Collision and Interference Resolution (RACIR) protocol.
• Development of a decentralized group split algorithm using probabilistic estimation to mitigate collisions.
• Implementation of a decentralized channel access procedure to overcome the HPT problem and incumbent receiver interference.

Main Results:

• The proposed RACIR protocol effectively reduces collisions and interference in CR-based IEEE 802.11ah systems.
• Decentralized algorithms minimize signaling overhead, even with frequent changes in the number of participating IoT stations.
• Performance analysis using Markov models and analytic expressions demonstrates promising results in normalized throughput, packet delay, and energy consumption.

Conclusions:

• The RACIR protocol is a viable solution for efficient spectrum management in CR-based IoT environments.
• Decentralized approaches offer a scalable and robust alternative to centralized architectures for IoT networks.
• RACIR shows strong potential for enhancing the performance and reliability of IoT communications over licensed-free spectrum bands.