Dynamic Bandwidth Scheduling for QoS Enhancement over IEEE 802.11 WLAN

This paper describes a dynamic Scheduled Bandwidth Reservation/Fairness MAC control scheme for real-time data (rt-data) service and non-real-time data (nrt-data) service of WLAN condition. It uses a schedule table, which is different from the table of IEEE 802.11, maintained in each station to allocate medium accessing time. It specifies a CYCLE period that includes contention free period (CFP) and contention period (CP). CFP is beginning from a Beacon frame that contains the schedule table. The difference from IEEE 802.11 standard is the CFP used to transmit not only rt-data but also nrt-data and CP is only used to transmit management frame for unrecorded stations to apply to record into the schedule table. Each recorded station would not contend the medium during the CP. And the CP can be used as extension period for rt-data service. It means that if bandwidth is fully filled by rt-data service, then no new station would be allowed to join the WLAN. So it reduces collision sensibly and provides enhanced rt-data service and nrt-data service.