IPv6 Internet Access Technology For Ad Hoc Networks

The booming trend of Wireless LANs indicates that wireless networking israpidly becoming a prevalent form of communication. As users become moreaccustomed to the use of mobile devices, they increasingly require the additionalbenefit of roaming. The Mobile IPv6 protocol has been developed as a solution forallowing users to roam outside of their home networks, while still retaining networkconnectivity. However, the deployment of Mobile IPv6 with WLAN is expensivebecause coverage areas of WLANs are limited due to fading and interference. Toreduce the number of required Access Pointes while still maintaining the samecoverage, Ad hoc network functionality can cooperate with Mobile IPv6 such thatmulti-hop routes between mobile nodes and APs can be utilized. In this thesis, we present a method for enabling the cooperation of Mobile IPv6and the Ad hoc routing protocol, such that mobile nodes that are not within directtransmission range of an access point can still obtain Internet connectivity. Firstly, wehave modified the Mobile IPv6 protocol, in order that the protocol can cooperate withmobile Ad hoc networks. Secondly, we have made an extension to AODV protocol,using our algorithm to discover gateways. Finally, a lot of simulation experimentshave been carried out under NS2, and three approaches for gateway discovery areimplemented and for performance camparison. The result of the simulationsdemonstrates that the proposed gateway discovery mechanism added to AODV worksproperly. In addition, we have built up a test-bed based on Linux system. An AODVimplementation for IPv6 has been completed, which provides foundation for thefurther work.