Enhancing the selection of backoff interval using fuzzy logic over wireless Ad Hoc networks

Area of Science:

• Computer Science
• Electrical Engineering
• Wireless Networking

Background:

• IEEE 802.11 Distributed Coordination Function (DCF) is the standard for wireless ad hoc networks.
• The random binary exponential backoff (BEB) mechanism in DCF is inefficient and unfair under heavy network load.
• Existing algorithms for tuning the contention window (CW) often result in random backoff intervals, leading to suboptimal channel access and increased delays.

Purpose of the Study:

• To propose a novel algorithm that enhances medium access scheduling in IEEE 802.11 wireless ad hoc networks.
• To improve fairness and efficiency, particularly under heavy network conditions.
• To address the limitations of random backoff intervals in existing protocols.

Main Methods:

• Developed a fuzzy logic-based algorithm for medium access scheduling.
• Implemented a new contention resolution level that prioritizes nodes based on queue length and waiting time.
• Utilized node overhearing to collect input parameters for fuzzy logic computation.
• Evaluated the proposed algorithm using the ns-2.35 network simulator.

Main Results:

• The proposed algorithm demonstrated improved performance compared to standard IEEE 802.11 and Gentle Distributed Coordination Function (GDCF).
• The fuzzy logic approach effectively schedules medium access in a fair and efficient manner.
• Prioritization based on queue length and waiting time mitigated issues of unfairness and increased delay.

Conclusions:

• The novel fuzzy logic algorithm offers a significant enhancement to IEEE 802.11 DCF for wireless ad hoc networks.
• The method provides a fair and effective approach to medium access scheduling, outperforming existing protocols.
• This research contributes to more robust and efficient wireless network performance.