The Design And Implement Of Logic Link Control Protocol On Gb Interface Of WCDMA R99 System

Now our society has entered an information society. Without the transmission and exchange of information, people can’t adapt to the fast pace of modern life and work. Comprehensive utilization of mobile communication wireless and wired transmission mode provides a fast and convenient means of communication. The communication systems include the AMPs and TACs as the representative of the first generation of analog communication system, the second generation digital communication system represented by GSM, GPRS and EGDE to 2.5G, and even to the development of 3G communication system as WCDMA and CDMA2000, and the representative of the 4G LTE which is the limelight in recent years recently. In the process of the development of the various types of mobile communication standard, we need to consider how to ensure the upgrade compatible, and the protection of the customers’ network investment, reducing the cost and upgrading the network operation and maintenance costs. So in the development stage the standard interface protocol compatibility, smooth transition should be considered. As the first 3G version, WCDMA R99 system was considered of the dependence of GPRS PS domain of 2.5G users’ service, providing RNC and GB port and IU port and docking capability.Based on the 2.5G GPRS to the WCDMA version of R99 smooth evolution as a starting point, we analysis the Gb protocol stack framework and requirements, and focus on the LLC protocol functions. Based on the existing system of ZXWN, we design and develop the LLC protocol and test it on the device.The LLC protocol in the actual device is divided into two sub modules as LLC-C and LLC-U.LLC-C is responsible for the LLC signaling control and user plane processing, message interaction of internal control mainly LLC and GMM, SM, TOM control signaling transport of signaling messages and protocol, and the user plane processes mainly to complete the LLC data frame transmission, package decapsulation, establish and confirm the link mode. This project is focused on LLC-C module, including tlli assigning, SM session processing and paging flow and so on.