Research On Internet Access Sharing Mechanism Via Ad Hoc Networking

The rapid development of mobile Internet technology has changed people's lives and work,the demand of accessing the Internet anytime and anywhere to obtain information and services is growing. Although the network coverage is more and more complete,there still exist situations when the signal of users' devices in their area is not good, or they are too far away from the public Wi-Fi hot spots, or they may have no Wi-Fi hotspot password. In addition, even if the users have the ability to directly connect to 3G / 4G networks, due to the data restriction they prefer to use free or low-cost Wi-Fi network to connect to the Internet. Similar needs exist in some disaster scenarios, if those devices which still have Internet access share their abilities, rescues could be organized effectively and timely. In these scenarios, it is necessary and significant for part of the devices sharing the ability of accessing to the Internet, and all the devices setting up a mobile ad hoc network to achieve Internet access.This thesis studies the scenario of mobile devices setting up mobile ad hoc network to access the Internet, designs Internet access mechanism ensuring the quality of service, combining with the status and characteristics of the Internet channel. The main work of this thesis includes:(1) Design of the overall Internet access sharing scheme. In the Internet access sharing scenarios, the nodes are divided into three categories: leaf nodes, relay nodes and gateway nodes.When a leaf node sends the route request as needed, the gateway node performs indirect path detection to optimize its access to the Internet channel at the same time. Two different scenarios are designed for common access and QoS access. The different processes of different types of nodes are discussed.(2) Study of the supporting technologies for Internet access sharing. The method of building a mesh topology based on virtual interface is studied, and a QoS routing protocol called LPAODV based on AODV protocol is proposed. The thesis designs the interaction process, extends protocol format and routing table in order to meet the QoS requirements.(3) Design of the routing metric considering the node resource consumption. The resources of the mobile devices are limited, and traditional routing metric makes it easy for nodes located in the center of the network to consume too much resources, thus a new routing metric considering the node load and power consumption is designed to improve the quality of the selected path,enhance the overall network performance and improve the resource utilization.(4) Simulation tests on LPAODV routing protocol. The scenario of Internet access sharing is simulated on the network simulation platform, where functional testing is performed and LPAODV routing protocol is compared with AODV protocol and other improved protocols. The performance in terms of average throughput, average end-to-end delay and residual power is analyzed. The simulation results show that LPAODV routing protocol can support Internet access sharing and ensure high performance.