Research Of In-vehicle Information System Base On IPv6

With the rapid development of computer networks and improvement of in-vehicle techniques, the in-vehicle information system has been the most important part of intelligent traffic system (ITS). As the development of IP networks, the small address space of IPv4 is not satisfied to the future network requirement, and IPv6 is designed to solve the issue of IPv4. With the combination of IPv6 and in-vehicle information system, there will be an available method for supporting ITS. Considering the current network situation and related technologies, we designed two different modules of in-vehicle information systems, and two different tunnel modules has been designed and realized in order to solve the issue of"IPv6 islet"connect the IPv6 hosts through the IPv4 networks,. For the necessary of heterogeneous wireless network interworking in in-vehicle information system, A tunnel VPN module has been planned to implement the vertical handoff, and at the same time, the security of the transmit has been improved. The main contributions to this dissertation are summarized as follows:(1) An integration in-vehicle information system is presented and implemented. The hardware platform of this system is based on ARM920T; it includes the S3C2410 CPU, 64MB SDRAM memory and 16MB FLASH static memory. The CAN/LIN in-vehicle control network node interface, GPS system device, CDMA wireless network module and USB wireless network card are all integrated in one interface board. The software platform is ARM-Linux, and background applications can send both CAN/LIN and GPS information together to the remote IPv6 host. For the independence sending and receiving queues, an algorithm called WRR-T is designed to improve the scheduling of the queues. (2) Based on the virtual network devices (VND) in Linux system, a modeling in-vehicle information system is put forward and implemented. The core component of this module is in-vehicle gateway. The characteristic of dynamic module loading and unloading in Linux OS is utilized to implement the virtual network devices. All the messages of different devices or networks which are interconnected to the gateway will be repacked in the module. Logically, the VND is the higher level above the other real device drivers, and unified the interfaces of the applications to the system. Take the CAN virtual network device for example, we use M/M/1 queuing model to analyse the performance of the VND, and get the testing results to prove the model.Due to the VND of GPS, CAN/LIN and wireless network card, the designing, development and maintenance of the applications are more convenience. With the IPv4 and IPv6 double protocol stack supported, most security and routing policies can be utilized in the gateway to protect the vehicle system or support different accessing hosts.(3)According to the different modules of in-vehicle information system in mentioned above, we set two different tunnel modules to transmit the IPv6 packages through the IPv4 networking. In the integration in-vehicle information system, a tunnel module called IPv6-CIPE is set to connect the system with remote IPv6 hosts. CIPE is the basic module and all the functions in the module are modified to support IPv6 protocol. The packages will be encrypted in CIPE core module which is running in Linux kernel.Virtual network tunnel module (VNTM) is applied for modeling in-vehicle information system. This module is especially designed for the Linux OS,because the packet_type data structure is available in Linux only. Using the packet_type data structure we can register our own protocol to catch the packets from virtual device,and encapsulates the IPv6 packets into IPv4 data area or disassemble the IPv4 packets with IPv6 data messages. (4)A heterogeneous wireless vertical handoff system based on tunnel VPN in integration in-vehicle information system is brought forward and implemented. In consideration of one-dimensional search strategy about unrestraint optimalization problem, we set a method called golden section to adjudge the handoff threshold. The whole handoff system is based on ARM920T hardware platform and ARM-Linux software platform.The IP address handoff depends on the address register to the address transmit server, and the address register is a part of virtual network device interface. The virtual network device interface can binding the address and port in IP level between the tunnel input interface and output interface. The system can make handoff between CDMA and WLAN, and provide more service of networking resources.