On Distributed Multi-User Multi-Channel Handshake And Access Protocol In Cognitive Radio Networks

Currently, it is becoming a hot topic to lucubrate the typical handshake and access protocols in cognitive radio networks, where the spectrum is of dynamic characteristics in multiple dimensions. Especially in the distributed multi-user multi-channel cognitive radio networks, without central controller and primary users appearing at any time, when multiple cognitive users(CUs) need to access multiple channels for data transmission though handshake at the same time, it suffers from collisions among CUs when they select and access the same channel. In this paper, we focus on diving into the distributed multi-user multi-channel handshake and access protocols to solve these problems. Compared with previous works, our schemes outperform the state of the arts in terms of channel utility, etc.In this paper, we firstly make a simple introduction of the categories and characteristics of the distributed multi-user multi-channel handshake and access protocol in cognitive radio networks. Then we mainly narrate the protocol based on the rendezvous couple channel hopping(RCCH) sequence, and propose an improved handshake and access protocol by separating data from control information in each slot, making them transmit on the channels whose labels of different parities, which avoids the collisions and improves the channel utilization. Morever, to make full use of the channels, we put forward a grouping time-division fair share(TDFS) handshake and access protocol by a detailed study of the existing TDFS strategy based on the MAB model. The proposed approach allows CUs to seek opportunities in different groups of channels at the same time for handshake and data transmission through rotating their priorities. In the case where the number of CUs is less than that of channels, the grouping TDFS protocol avoids the collisions among CUs, improves the cumulative access time of the system and the channel utilization and guarantees the fairness among CUs. Finally, we build the multi-user multi-channel experimental platform using USRPs on the LINUX and GNU Radio, accomplishing the experimental verification of the proposed grouping TDFS handshake and access protocol by collecting actual data.