Mobile Ipv6 Handoff

With the development of Internet and mobile communicationtechnology, mobile terminal equipments were introduced into Internet.Thereby IETF published the Mobile IPv6 Protocol to solve the mobilemanagement problems. However, this standard MIPv6 protocol has somelimitations such as long handover delay and high packets loss ratio whichcan't meet demands of delay sensitive real-time applications.For improving handoff performance, IFHMIPv6 (InformationExchange-based Fast Handover for Hierarchical Mobile IPv6) is proposed.With information exchange, mobile node foreknows the neighboringrelationship of access routers and their related information, which helps toreduce the time of radio access network discovery and candidate accessrouter discovery. By adjusting signaling flow of FMIPv6 over HMIPv6,the operation in anticipation phase is simplified, so that overall handofflatency and packet loss are reduced. Furthermore, IFHMIPv6 sets thetunnel timer for reserving the tunnel established in the previous network,so that large signaling cost introduced by mobile node's ping-pongmovement can be avoided.An evaluation matrix-based handoff decision which can be applied inIFHMIPv6 is proposed to choose the optimal network for handoff. Firstly,the processed received signal strength is used to obtain available networks.Following, several metrics such as network cost, bandwidth and securityare considered and combined with respective weights to construct anevaluation matrix for choosing the best network to handoff. This methodis convenient to execute and the handoff connection dropping probabilitycan be reduced.In order to verify the feasibility and validity of IFHMIPv6, simulationexperiments are executed and compared with other handoff schemesunder NS-2. Simulation results show that IFHMIPv6 holds the merit oflow latency and low packet loss and the overall handover performance isimproved.