QoS-based frequency selection for coexisting 802.11 RLANs

In this paper, a distributed, dynamic, frequency selection and multicarrier scheduling scheme, called Distributed, QoS-based, Dynamic Carrier Reservation (D-QDCR) is proposed. D-QDCR allows coexisting IEEE 802.11 access points of different providers to contend and reserve a carrier, based on QoS demands, and to distribute the allocated carrier, as well as the reserved time, to the associated wireless terminals, enabling the spectrum agility paradigm. D-QDCR, using distributed estimations of the required QoS, seeks to schedule for transmission an access point when its transfer requirements are at their peak in order to accomplish the QoS contracts and to achieve fairness. Additionally, through self-organized and etiquette policies, it mitigates interference situations, avoiding the waste of the scarce electromagnetic spectrum. Results show that the proposed dynamic frequency selection and scheduling scheme outperforms conventional scheduling in terms of data losses, transfer delays and efficiency.