Research On The House Netwoks And Security Mechanism Based On The Ad Hoc Technique

Home network is an intelligentized service network system which can connect the in-house nodes each other, offering consumers entertainments, data transmission and home electric appliances etc. The in-house nodes can enter internet through the house gateway. Broad band wireless technology is the best network construction technology for home networks. Ad hoc network is a wireless network which is composed of locomotive nodes and independent of any immovable basic establishments. Ad hoc network fits the situation well where there are no communication basic establishments or the basic establishments can not be used because of the characteristic that it dos not need the supports of immovable basic establishments. Hence, it has wide potential application domains. Locomotive Ad hoc network can be built without network basic establishments in a small area at any moment, so that it benefits to construct a home network with simple operations, flexibility, low price and small area. Therefore, this dissertation has put forward a wireless home network based on Ad hoc network and research on layer model of home network, Ad hoc network router protocols and the security strategies and mechanism of Ad hoc home network.This dissertation has proposed the layer model of wireless Ad hoc home network based on OSI model after it has researched the CSMA/CA protocols and its DCF mechanism of MAC layer in channel share technique in data link layer and channel occupied rate of MAC layer. And it has designed a communication subnet used in communication between nodes of home network, including physical layer, data link layer and network layer, and analyzed and researched on transmission technique in physical layer, channel share technique in data link layer and router technique in network layer. Simulation results show that this kind of network structure has the feature of improvisatorial organizing, simple operations, flexibility, and low price etc, which can satisfy the requirements of home network.Router protocols are the key technology of Ad hoc network and one of the most important factors which can influence the performance of the whole network. In conventional immovable networks, connections between host computers are immobile, and the system structure of network is hiberarchy, has a steady topological structure, can provide router service, naming service and catalog service, and can implement relative security strategies. However, in mobile Ad hoc network, there are no base stations or central node, all nodes are locomotive, and its topological structure are dynamic. Nodes are connected by wireless channel. There are no expert routers and the node itself works as a router and it has no functions such as naming service and catalog service. Thus, new router protocols have to be designed because the conventional router protocols can not suit the dynamic topological structure of the Ad hoc network. This dissertation has studied and designed the Ad hoc home network router, especially studied on the optimization of network layers. And it has improved the AODV router based on a local self recover model of router, introduced the multicast protocols model in IPv6 into the Ad hoc home network, and designed A-DSR, the multicast router protocols based on DSR, to improve router quality. Simulation results show that both the throughout and performance of the protocols of Ad hoc home network has been improved.Moreover, Ad hoc network has many new services and applications because it is mobile, multi-jump and self-organized and can connect at any area and at any time. But, the insecure inbeing of wireless link route, the high dynamic topological structure of network and limit resources have also bought much new security threats. So, the security solutions to conventional networks do not entirely suit Ad hoc network any more. This dissertation has analyzed characteristics of Ad hoc network and security threats in detail and has proposed the security strategies of Ad hoc home network and relative mechanism based on the security requirements of Ad hoc and home network.Security router protocols are a most active domain in the research of Ad hoc network security because router protocols are quite important for Ad hoc network. Presently, the research of Ad hoc network security is still in a preliminary phase, and it is necessary to provide basic security services, authentication, key management and safe route, for networks. This dissertation has put forward a safe route mechanism based on combination of NTRU public-key algorithm and IDEA private-key algorithm and designed and realized it. Finally, this dissertation has constructed the CA system in security mechanism, adopting the strategy of combining off-line CA and distributing key management to ensure home network based on Ad hoc technology work well, be inexpensive, and especially be safe, with definite practical application significance.