Common Control Channel Based Cognitive Multi-hop Wireless Network Mac Protocol Design

With the emergence of more and more wireless network services and products,wireless network business are explosive growing. Spectrum resources becomeincreasingly scarce. And now almost all of the band are fully allocated, but thetraditional static spectrum allocation mechanisms leading to many licensed spectrumhole. In addition in the unlicensed ISM band, with the development of technologiessuch as WiFi, Bluetooth, it is a problem for the coexistence between different system.Cognitive radio (CR) technology is regarded as a key technology to solve thiscontradiction, in Cognitive radio networks cognitive devices (CRS) can dynamicallyperceive spectrum hole, opportunity to access these free channels, greatly enhance theutilization of the spectrum. We called those with cognitive equipment terminal seconduser (SU), those who use lisenced channel referred to as the primary user (PU).Spectrum holes in cognitive radio networks and spectrum sharing are the focus of thestudy. MAC (Media Access Control) play an important role in many cognitive radiofunctions. So the key to solving most of the problems are generally at the MAC layer.This paper first outlines the cognitive radio origin, core idea, the key technologyand application scope. Then we learned the existing MAC protocol for distributedcognitive radio network research. Analysis some of the typical cognitive networkdistributed MAC protocol, analysis the performance of SRP in MMAC protocol,improved and perfected the defects in SRP mechanism. Proposed a new perception andmerge mechanism: ESRP. Then, based on the ESRP perception and merge mechanismproposed distributed MAC protocol for cognitive multi-hop ad hoc networks withpublic control channel. For simplicity, in the protocol, cognitive users using Overlayway access free authorized channel, in other words, when the primary users are notusing authorized channels, the cognitive user can dynamically access these freechannels. For distributed self-organizing network, the paper analyzes the cooperativesensing and the establishment of the connection problem analysis and gives a solution.Finally, simulation the ESRP mechanism and analysis of the performance of the MACprotocol, to verify the performance of this protocol. The results of this research provides a useful strategy for distributed spectrum sensing and sharing for cognitiveradio network.Proposed ESRP priority-based backoff window algorithm, the algorithmof generate a list of available channels, channel selection algorithm based on scanresults.Provide a valuable reference for future research.