The Designment And Implementation Of Wireless Backhaul Based On LTE

With the popularity of intelligent terminal, the demand of mobile users for data is continuously rising. In order to improve the user experience of mobile communication system, all the major mobile network operators are scrambling to deploy of LTE systems for bandwidth enhancement. LTE has many advantages in high capacity, low latency, simple network structure and so on. Since in dense urban area the LTE system configures many microcells, the backhaul issue has become a huge challenge for the major mobile network operators. Wireless backhaul has become an important solution with its advantages of low cost, fast deployment, convenient operation from many backhaul schemes.This thesis design and realiz a wireless backhaul system based on LTE system, it transmit the hackhaul signals through the existing LTE network. Since the LTE network has been widely deployed, this system can greatly reduce costs in existing network.In this thesis, according to the system functional characteristics, we divide the overall structure to control plane subsystem and user plane subsystem and then design them separately. We go into the significant IP transparent transmission problem and the QoS guarantee problem, and make innovate solutions for them. The message-driven mechanism was used in the user plain subsystem designing, it make the program go into different program flow when different kind of S1AP messages arrive, then process/forward/resopond the message further, and push the corresponding config parameters to the user plane subsystem. In the user plane subsystem part, when the config parameter comes, the corresponding bearer will be created/modified/deleted, and then the subsystem will listen to the user data. When backhaul user package arrives, the system will encapsulate or de-encapsulate the package according the data source address, and then forward them to the corresponding network. At last, the two subsystem are integrated for functional and performance test. According to the test result, the thesis checked the functional correctness, analysed the performance of the whole system and fix the application situations by its characteristics.