Analysis and simulation of a fair queueing algorithm
SIGCOMM '89 Symposium proceedings on Communications architectures & protocols
A Service Discipline for Support of IP QoS in IEEE 802.11 Networks
PWC '01 Proceedings of the IFIP TC6/WG6.8 Working Conference on Emerging Personal Wireless Communications
Quality-of-service in ad hoc carrier sense multiple access wireless networks
IEEE Journal on Selected Areas in Communications
Weighted round-robin cell multiplexing in a general-purpose ATM switch chip
IEEE Journal on Selected Areas in Communications
MPEG-4 and H.263 video traces for network performance evaluation
IEEE Network: The Magazine of Global Internetworking
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This paper addresses the support of IP with Quality of Service (QoS) in IEEE 802.11b WLANs. Both the Distributed Coordination Function (DCF) and Point Coordination Function (PCF) modes of operation are analysed and compared. For DCF, both the original standard and some of the enhancements proposed for IEEE 802.11e are considered. For PCF, two alternative scheduling disciplines are considered: Scheduling based on Estimated Transmission Times (SETT) proposed by the authors and Weighted Deficit Round Robin (WDRR). It is shown that while WDRR is suitable to perform fair bandwidth distribution, SETT also takes into account maximum transmission delay and service priority. Simulation results show that DCF cannot be used to support IP QoS even if 802.11e enhancements are used. On the other hand, PCF performs better with SETT than with WDRR. SETT is able to keep a similar level for network utilisation, while fulfilling the QoS requirements of real-time services such as packet telephony and videoconference, even in the presence of lower priority bursty data. The impact of the high overhead introduced by the IEEE 802.11 PHY and MAC layers was also evaluated, showing that for small packet traffic such as Voice over IP traffic, advanced voice compression is of limited usefulness.