The Research Of The Interconnection Problem Between Mobile Ad Hoc Network And Internet Based On Gateway

With the rapid development of Internet and wireless communications, as wellas the improvement of the living standards of the people, people more anse rely onservices provided by the Internet, and look forward to access to the Internet throughthe wireless device anytime and anywhere.In the meanwhile, remain communicateon the mobile situation. Although, the emergence of the Mobile IP protocol allowsusers to access and roam at any time, but this protocol needs the support of networkinfrastructure. However, the coverage of the network infrastructure is limited, andthe cost and performance of layout infrastructure are far can not meet the needs ofmobile users. Thus, the interconnection of Mobile Ad Hoc network (MANET) andInternet have been proposed, so that mobile users will access to the Internet in thelower cost under the non-infrastructure conditions.How to achieve an efficient interconnection between Mobile Ad Hoc networkand Internet within a reasonable overhead is becoming a hot issue in the industry.The domestic research is in its infancy. Although similar to the sensor networks, Adhoc networks are born to interconnect with the fixed network, but such a networkwas initially designed as an independent autonomous system. So those twoheterogeneous networks want to interconnect is not easy. We need to address suchkey issues as gateway design and service discovery, address auto-configuration,gateway forwarding strategy, QoS support, mobility management, and so on. In theview of this, this paper preliminary study and summarize the key technical issues ofMobile Ad Hoc network. For the gateway selection and multipath interconnectionof Mobile Ad Hoc network and Internet, I study and propose the correspondingsolutions. The theoretical analysis and NS2simulation experiments all verify thesuperiority and effectiveness of these programs. These studies have a greatsignificance on further carrying out of Ad Hoc network in the commercial area.The innovative work of the paper is mainly reflected in the following twoaspects: (1) For the gateway selection problem of the interconnection of Mobile AdHoc network and Internet, I propose the gateway optimization strategy based onmultiple indicators. The program takes the number of hops from mobile node to thegateway, the gateway load, the link reliability as the preferred indicator. Calculatingthe utility function of standby in the light of the weighted algorithm. And chooseingthe access gateway and alternate gateway according to the utility function. Weswitch directly to the alternate gateway after the failure of the access gateway.Compared by the simulation, this program greatly extends the live of the networks,improves packet delivery ratio, realizes gateway load balance, and greatly shortenthe average end-to-end packet delay. Especially, when the numbers of the sourcenode increases, the advantages of the agreement are better reflect.(2) Proposing a path-quality-based multi-path routing mechanism in theinterconnection of the Mobile Ad Hoc networks and Internet. In a gatewaydiscovery process, the new interconnection protocol based on DSR multipathrouting protocol establishes multiple paths, which are from mobile node to thegateway. And it make use of restrictive constrains that the intermediate node doesnot repeat the same message forwarding in order that these paths are none-nodereuse. At the same time, using these path access to Internet, which can not onlyprovide QoS support, but also get the higher available bandwidth. Because ofwithout having to re-launch the gateway discovery process before the breaking ofthe global routing, so the gateway discovery overhead and delay will besignificantly reduced. The simulation results show that this program is significantlybetter than the access performance of the single-strength interconnection protocol.