Wireless Mesh Network Testbed Design And TCP Performance Test Analysis

The wireless Mesh network, a new wideband network structure, is a kind of high-capacity and high-velocity distribution model, featuring convenient building, low cost, high reliability, and self-organization. In a wireless Mesh network, TCP performance indicators such as throughout and congestion control affect the performance of the network. On the other hand, factors affecting TCP performance vary, such as link layer ,MAC layer and routing layer. Nowadays, the research on the TCP performance of wireless network is mostly based on simulation experiments, which are not able to reflect the authentic condition of network running and therefore have some negative effect upon research jobs. Hence, it is essential to set up an authentic experimental environment.Taking the above problems into account, the research mainly undertakes the following jobs:Based on the in-depth analysis of the current wireless Mesh Network Testbed, MIT Roofnet Wireless Mesh Network Testbed is chosen. Also, wireless Mesh nodes are built based on PC and the hardware frame of Netgear wireless router.Based on the Network Testbed set up, under different typology structures, multiple tests are carried out through changing maximum congestion window and two important parameters, RTS/CTS and MAC rates.The experiment data are collected and the test results are demonstrated through tables. The relations between TCP throughout and congestion window, MAC rate, and RTS/CTS, are described respectively. Also, the effects upon TCP throughout arsing from the maximum congestion window, MAC rate, and RTS/CTS are analyzed.The findings indicate that, in a Mesh Network, TCP throughout decreases rapidly with the increase of hops. Under different hops, RTS/CTS influences TCP throughout differently. For different maximum congestion window, TCP throughout is also affected differently according to different hops, different rates and different RTS/CTS. No consistent optimal value is available therein.