Research And Implementation Of The System Control-flow Communication Protocol In BSS

The mobile communication network based on IP technology is the certain trend for the development of mobile communication technology. 3 GPP2 organization has proposed CDMA2000 spread-spectrum mobile communication network which bases on IP technology. In the process of combining IP technology with mobile communication network, a few improvements need to be made on some protocols of traditional TCP/IP protocols stack. The improvements are in the purpose of strict telecomm demands of the mobile system. ZTE ZXC10-BSS is an implementation of CDMA 2000 standard. ZXC10-BSS software system is a large-scale distributed system applied into the mobile communication area. It is composed of many modules which communicate with each other through specific protocols and the system functions as a whole through the mutual coordination among modules.This dissertation focuses on the research of the choice of the transmission layer in traditional TCP/IP protocols stack in mobile communication network. Choosing the right protocol is also an important problem in the implementation of IP technology in CDMA 2000 system. Nowadays net-meta always uses Ethernet as communication network. According to the characteristics of net-meta's internal communication, this dissertation has made detailed comparison of and done research on the characteristics of TCP and UDP. UDP is employed as the supporting protocol at the bottom of control-flow communication. But UDP itself can't ensure the reliable transmission of control-flow communication. RUDP (Reliable UDP) is proposed to realize the reliable transmission. RUDP adds a layer between transfer layer and application layer to ensure the reliable data transmission. A five-layer network architecture is established with UDP as the supporting protocol at the bottom. RUDP makes use of UDP to implement a kind of link-oriented and reliable data-transmission mechanism based on messages. RUDP integrates the reliability of TCPand the high efficiency of UDP. The operation of RUDP module relies on two tasks. One is UDP-driven task, the other is protocol processing task. These two tasks can cooperate with each other to maintain the state machines of every link as well as implement receiving and sending message.According to the characteristics of system control-flow transmission, this dissertation has designed and implemented a testing tool of control-flow transmission. This tool has done many tests on RUDP module in ZXC10-BSS system. The tests have promoted the constant optimization of RUDP module. The latest testing data shows RUDP technology can ensure the performance requests of the signal data transmission in the system. Meanwhile, the reliability and high efficiency of mobile communication can also be satisfied. At present, ZTE ZXC10 has successfully been applied into the overseas business mobile communication systems.