文档介绍：1506 IEEE TRANSACTIONS ON MUNICATIONS, VOL. 4, NO. 4, JULY 2005
Performance Analysis of Priority Schemes for
IEEE and IEEE Wireless LANs
Yang Xiao, Senior Member, IEEE
Abstract—The IEEE distributed coordination function attempt, CW equals the initial backoff window size CWmin.
(DCF) enables fast installation with minimal management and After each essful transmission, CW is doubled until a
maintenance costs, and is a very robust protocol for the best effort
maximum backoff window size value CWmax is reached. Once
service in wireless medium. However, the current DCF is unsuit-
able for real-time applications. This paper studies backoff-based it reaches CWmax, CW shall remain at the value CWmax until
priority schemes for IEEE and the emerging IEEE it is reset. CW shall be reset to CWmin after every essful
standard by differentiating the minimum backoff window size, the attempt to transmit or the retransmission counter reaches the
backoff window-increasing factor, and the retransmission limit. retry limit Lretry. After the destination station essfully re-
An analytical model is proposed to derive saturation throughputs, ceives the frame, it transmits an acknowledgment frame (ACK)
saturation delays, and frame-dropping probabilities of different
priority classes for all proposed priority schemes. Simulations are following a sho