Design And Implementation Of Embedded WiFi Terminal Supporting AODV

Since the traditional WiFi terminal equipments are expensive and only support single hop communications, it is critical to develop a kind of cost-effective, multi-hop and portable WiFi terminals. In this paper, based on the key technology of embedded system, wireless access and ad hoc networks, we design and develop an AODV routing supported WiFi terminal, which has the advantages of simple implementation, cost-effective, wide coverage and so on. We mainly complete the WiFi Internet access function and the AODV routing function. Furthermore, all of these functions are tested and the testing results are also given.First, we review the research status and the future development of technologies on embedded system, wireless access and ad hoc network. And then, we present the overall function framework of the system and describe the construction of the software and hardware platform, mainly focusing on the choice of the operating system, kernel cutting and transplant of the system for the building of software programming environment. Moreover, the implementation of the Internet access of WiFi terminal and the AODV routing function based on the platform of ARM11 is elaborated. （1） the processer ARM11 of the Samsung S3C6410 is chosen as the development platform and the embedded Linux operating system with a graphic interface is ported into the platform. The wireless card is started up correctly by studying the wireless card drive and porting the wireless toolset commands. At the same time, local area network （LAN） access point ZTE_AP₃974 is virtual out with the use of a smart phone. The LAN access and the Internet access are achieved by the command operation of the wireless card character under the Linux system. （2） to generate ad hoc network by setting wireless card model on the embedded nodes being loaded wireless card driver and to transplant iptables with the functions of shielding the MAC address of nodes; to analyze the AODV routing protocol and to transplant it to the embedded platform by adding the packet filter framework Netfilter function, the routing source modification and the cross compilation; to develop a mini-telnet program with AODV routing function by the write of the network programming of server and client socket. Finally, the function of the developed embedded WiFi terminal is tested. The testing results show that the system is operating normally and the desired effects are achieved.