Spectrum Aware Based Multi-Channel Opportunity Routing Protocol In Cognitive Radio Sensor Networks

In recent years, wireless sensor networks (WSN) has been widelyused and got a fast development. Meanwhile, single-channel environmentis difficult to meet the requirements as the demand for data traffic isincreasing. The application of multi-channel technology makes thisproblem to be alleviated, however, the used2.4GHz band becomes moreand more crowed and the utilization of some licensed band unluckily to bevery low. Thus, Cognitive Radio Sensor Networks (CRSN) lead to be anew research direction in the field of wireless communication, and routingis one of the most important parts in CRSN.Firstly, this thesis has made researches on multi-channel routingprotocols in CRSN and know that existed routing protocols can be dividedinto two parts，spectrum aware based multi-channel routing and spectrumunaware based multi-channel routing. At the same time, there are a lot ofchallenges when designing the routing protocol in CRSN, for instance, thechannel detection problems in cognitive radio systems, the channelnegotiation mechanisms between nodes, the interface configured problemsin sensor nodes and the selection of path cost functions.Then, this thesis put forward a control channel based cross-layermulti-channel negotiation mechanism after a better understanding of theopportunistic routing mechanism and traditional multi-channel MACmechanisms, which is called MCOMAC. This mechanism is acombination and improvement of the above two mechanisms, and it isapplicable to multi-channel opportunistic routing protocols if we know theforwarding candidate set and its priority order for every node in thenetwork. We call it is a cross-layer mechanism because during the negotiation process between the sender and its forwarding candidate set,not only the channel used to be transmit the data packet is determined, butalso the next hop node has been selected to forward the packet. Thus,MCOMAC can be viewed as a combination of routing layer and MAClayer, so called cross-layer mechanism.Then, this thesis proposes a spectrum aware based multi-channelopportunistic routing protocol in CRSN, which is called MCORP. Themost important parts in an opportunistic routing are the construction offorwarding candidate sets and the process of data packet transmission. InMCORP, we consider the instability of wireless links and assume that theprimary user and spectrum are aware to all nodes, we can calculate thedelivery ratio and expected transmission count for each link and this twometrics are used to assign the priority order of the candidate sets. Whenconstructing the forwarding candidate set, we considered the delivery ratiomodel, the energy consumption model and the delay increase model andproposed a candidate set modification algorithm, thus, the forwardingcandidate set of each node can be constructed. After all of the above, thedata transmission process is almost the same with MCOMAC mechanism.Finally, this thesis simulates the routing protocol MCORP with NS2and compares its performance with an existed multi-channel routingprotocol (MCRP).