Application Of VoIP Service In Wirless Mesh Network

In recent years, VoIP has rapidly developed. A variety of business models and products are emerging (such as Skype, MSN etc).Recently, the wireless LAN in the home and the office become more and more popular, there is growing concern about a hot issue, VoIP how to apply in the wireless Mesh network environment. Once VoIP can be used in the wireless Mesh network, they can provide great convenience to users. The Performance of VoIP over wireless mesh network became a hot-Point in research areas. VoIP requires the low delay, low packet loss rate, low delay jitter, satisfying the QoS requirement is a big challenge for wireless mesh network,First, the paper proposes a new routing metric—(Enhance Metric) EMetric based the feature of high real-time and voice synchronization requirements in VoIP service. EMetric also takes into account the factors of delay jitter and delay. Delay is an important factor which affects the real-time of VoIP service, and delay jitter is the important factor that affects voice synchronization. To a large extent, they will affect transmission performance of VoIP services in wireless Mesh network. EMetric inherits the advantages of ETT and WCETT, takes into account the characteristics of VoIP service, and optimizes the transmission performance of VoIP service in wireless Mesh network. The paper uses the OPNET as the simulation tool. The simulation results also show that, compared with the ETT and Ca, the EMetric can reduce latency and packet loss and bring a certain degree of improvement in the transmission performance of VoIP service.In view of the wireless mesh network, link stability is worse than the wired network. Broken link will increase the cost of route maintenance phase. To reduce such losses, the paper modified the traditional hybrid routing protocol (Hybrid Wireless Mesh Protocol) HWMP based the structural characteristics of the wireless Mesh network and VoIP services, and proposed a new routing protocol—(Enhance Hybrid Wireless Mesh Protocol) EHWMP. Compared with the HWMP, EHWMP protocol reduced network delay in route maintenance phase. Delay jitter and packet loss rate have been markedly improved. EHWMP protocol also provides support for mobility of Mesh terminal node by Flat Routing-Based Scheme. The paper uses the OPNET as the simulation tool, uses the number of VoIP connections which are supported by unit bandwidth to measure the transmission performance. Simulation results prove that, compared with the HWMP and M2-HWMP, the EHWMP protocol reduce the delay during the route maintenance phase and increase the number of VoIP business connections. The EHWMP protocol improved the transmission performance of VoIP in the wireless Mesh network.