| Wireless ad hoc network is a multi-hop peer, self-healing wireless network without central control node, which is widely used in people’s production and life. Among them, the performance of the media access control (MAC) protocol largely affects performance of wireless networks. Traditional wireless ad hoc networks use single-channel MAC protocol, in which packet collision probability is great and network throughput is low. With the rapid development of communications and computer industries, more and more frequency opens up, which highlights the shortcomings of poor performance of single-channel MAC protocol and channel wasted. So multi-channel MAC protocol quickly becomes a hot topic.On the basis of in-depth study of existing MAC protocol, a multi-channel MAC protocol wireless ad hoc network (multi-channel MAC protocol based on channel negotiation, CN-MMAC) is implemented in this thesis. The main idea of the protocol is: Control channels and data channels are separated and each node maintains a list of channels which are used. Channel reservation of the node is completed on the control channel through broadcast message and the handshake message. Data packet transmission is completed on data channel res ervatied successly.The main work of this thesis is as follows:The design of multi-channel MAC protocol:The existing MAC protocol is analyzed from the basic concept of wireless ad hoc networks and indicates the current issues that exist in this thesis. A wireless ad hoc network based on channel negotiation of multi-channel MAC protocol (CN-MMAC protocol) is designed, specifically address the following issues:the assignment of channels, the hidden terminal problem of multi-channel and control overhead problem.Performance research of multi-channel MAC protocol:The simulation model is modified using NS-2 simulation tools and multi-channel MAC protocol is added. The performance of other protocols is analyzed in this thesis and it is proved that multi-channel MAC protocol designed in this thesis has a higher performance.Realization of multi-channel MAC protocol:Multi-channel MAC protocol designed in this thesis is transplanted on the hardware platform, which provides transparent transmission interface on MAC layer protocol stack for wireless ad hoc networks. Prove this design has better portability and good practical value.Research on quality of service (QoS) of multi-channel MAC protocol:Different back off algorithm is based on business priorities to adjust channel access mechanism. It is proved that this scheme can improve the quality of real-time business services effectively.Summary of the thesis:indicates the direction of work and research in the future. |
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