Efficient, flexible, and scalable inter-network spectrum sharing and communications in cognitive IEEE 802.22 networks

Although avoiding harmful interference to licensed incumbents is the prime concern of the system design for the emerging IEEE 802.22 standard, another key design challenge to cognitive radio based 802.22 systems is how to dynamically share the scarce spectrum among the collocated 802.22 network cells so that performance degradation, due to mutual co-channel interference, is effectively mitigated. This paper describes a distributed, cooperative, and real-time spectrum sharing protocol called On-Demand Spectrum Contention (ODSC) that employs interactive MAC messaging on an inter-network communication channel to provide efficient, scalable, and fair inter-network spectrum sharing among the coexisting 802.22 cells. Additionally, in order to support ODSC and other inter-network coordination functions in 802.22, we introduce a beacon-based inter-network communication protocol called the Beacon Period Framing (BPF) protocol that realizes a reliable, efficient, and scalable over-the- air inter-network communication channel utilizing the occupied RF channels of the network cells.