Performance analysis for IEEE 802.11 distributed coordination function in radio-over-fiber-based distributed antenna...

Area of Science:

• Wireless communication systems
• Optical networking
• Performance analysis

Background:

• Radio-over-fiber distributed antenna systems (RoF-DASs) integrate wireless local-area networks (WLANs) with optical fiber infrastructure.
• IEEE 802.11 Distributed Coordination Function (DCF) is crucial for managing shared wireless medium access.
• Varying fiber link lengths in RoF-DASs introduce unique performance challenges.

Purpose of the Study:

• To analyze the performance of IEEE 802.11 DCF in simulcast RoF-DASs.
• To develop an analytical model for evaluating system throughput.
• To investigate the impact of inter-RAU hidden-node and fiber-length differences.

Main Methods:

• Developed an analytical model incorporating unequal delays from different fiber lengths.
• Included fiber-length-induced delays in backoff stages and busy time calculations (Ts and Tc).
• Evaluated throughput in both basic access and Request to Send/Clear to Send (RTS/CTS) modes.

Main Results:

• The analytical model accurately captures the performance degradation caused by hidden-node and fiber-length effects.
• Throughput is significantly impacted by unequal propagation delays across different remote antenna units (RAUs).
• RTS/CTS mode shows different throughput characteristics compared to basic access under these conditions.

Conclusions:

• The derived model provides a valuable tool for understanding and optimizing WLAN-RoF-DAS performance.
• Addressing fiber-length variations is critical for efficient operation of these integrated systems.
• Further research can explore adaptive mechanisms to mitigate these performance issues.