Modeling And Simulation Of Wireless MESH Network

With the rapid development of networks, the network scales become complicated and application scope extends continuously, so the performance of network is .more and more difficult to predict The construction of large and complex networks are often beyond the scope of people's experience. Modeling and simulation technology which is getting more and more attention, can provide a reliable basis and a valuable reference for the construction of new networks and gradually become a mainstream technology when plan, design and development of networks.Wireless Mesh Networks become a current research focus,for it's convenience of Networking,reliability in use,flexibility in covering and other obvious advantages. This paper introduces the concept of wireless MESH network, topology and future prospects in detail.The designer set up a wireless MESH network systemic structure from four aspects according to the order how the network data flows. The four sub-models are: self-similar source model, connection admission control and traffic shaping model, buffer management model and media access control model. The characteristics of modern network traffic is analyzed. It shows characteristics of burstiness and self-similarity. According to the the characteristics, heavy-tailed ON / OFF model is set up. We put emphasis on the influence to network delay because of self-similarity,then get that network size and buffer size also influence network delay. Leaky buckets model is used to fulfill the connection admission control and traffic shaping model. The first bucket let the data into network which comply with the traffic contract and the second one limit the date's speed. ADT algorithm is used in buffer management algorithm. Then DCF mechanism is adopted when setting the media access control model,and basic access mode and RTS / CTS access mode are all introduced. Through the establishment of two-dimension Markov chain,saturation throughput is derived. Then we use the OPNET simulation software to build up the simulation framework and simulate the delay and throughput. In the end, we have analyzed the factors which will influence the delay and the capability of the channel access throughput. What we do provide us a reference when we set up a wireless mesh network.