Mahdieh Ghazvini - Department of Computer Engineering, Faculty of Engineering, Shahid Bahonar University of Kerman, Kerman, Iran
Naser Movahedinia - Faculty of Computer Engineering, University of Isfahan, Isfahan, Iran
Kamal Jamshidi - Faculty of Computer Engineering, University of Isfahan, Isfahan, Iran

IEEE 802.11e is standardized to enhance real-time multimedia applications’ Quality of Service. This standard introduces four access categories for different types of applications. Each access category has four adjustable parameters: Arbitrary Inter-Frame Space Number, minimum Size of Contention Window, maximum size of Contention Window, and a Transmission Opportunity limit. A Transmission Opportunity limit is the time interval, in which a wireless station can transmit a number of frames consecutively, without releasing the channel and any further contention with other wireless stations. Transmission Opportunity improves network throughput as well as service differentiation. Proper Transmission Opportunity adjustment can lead to better bandwidth utilization and Quality of Service provisioning. This paper studies the dynamic adjustment of Transmission Opportunity in IEEE 802.11e using a game-theory based approach called Game Theory Based Dynamic Transmission Opportunity. Based on the proposed method, each wireless node chooses its appropriate Transmission Opportunity according to its queue length and media access delay. Simulation results indicate that the proposed approach improves channel utilization, while preserving efficiency in WLANs and minimizing selfishness behaviors of stations in a distributed environment.

Transmission Opportunity (TXOP); Game Theory; WLAN, IEEE 802.11e; EDCA.