Improved IEEE802.11 PCF performance using silence detection and cyclic shift on stations polling

The authors propose a cyclic shift polling method that can be used along with silence detection on IEEE802.11 wireless LANs for increasing the number of supported voice communications. The method spreads the total voice packet rejection rate to all active stations in order to increase the number of stations that experience specific voice quality. The cyclic shift polling method is implemented only at the access point of each wireless LAN and does not require any modifications to the existing access protocol. Analytic expressions and comparative numerical results are presented for the performance of the IEEE802.11 point co-ordination function. The analysis shows how the cyclic shift polling method along with silence detection on the mobile stations can be used for increasing the number of supported voice calls.