| With the popularity of intelligent terminals and rapid development of mobile Internet, the amount of traffic data increase significantly. In order to meet users' demands for the growing business, mobile communication technology evolves constantly. The evolution for the network is from 2G network mainly supporting voice calls to 3G network effictively supporting the mobile Internet application, and then to the 4G LTE system which is widely deployed and can bear various high-speed streaming media services. As known to all, each generation of mobile communication technology has greatly improved the system capacity and information transmission rate. However, due to the relatively small coverage of the LTE base station(BSs), a large number of BSs are required to achieve full network coverage. There is no doubt that it will increase operating costs and can be a daunting challenge for operators. In order to realize green economy under the condition of the “tide effect”, i.e., network load will vary at different time in different location, dynamic ON/OFF technology emerges, with which the total number of resourses of the network can be adaptively adjusted according to the traffic load. Meanwhile, the network energy consumption and the link interference can be mitigated. Therefore, this thesis focuses on the solution to choose suitable BSs to shutdown based on the network load in TD-LTE by combining with the novel network architecture of C-RAN and the tradition architecture. Then, two kinds of dynamic BSs switching strategies, i.e., the centralized and distributed strategis, are proposed. The main contributions of this thesis are as follows:1. Studying the problem of BSs ON/OFF under two kinds of network architecture of C-RAN and integrated BS. In detail, we combine the power model under two kinds of architecture, and the problem is modeled as an optimization model, which can minimize the network energy consumption under the constraint of user service quality demand and resource allocation. In order to solve the formulated problem, we combine the development of the future network and the present situation, put forward the centralized and distributed solutions and design two solutions from the perspect of network operators. Finally, the application scope and performance of each solution has been analyzed.2. In order to evaluate the strategy of the base station, using the key technologies of LTE, and combining with the real operation data of operators to build simulation platform. In order to carry out the effective analysis of the BSs ON/OFF strategy, multi-layer network is also introduced into the simulation platform. Finally, we compare the simulation platform with other platforms. Then, the advantages of the platform in dimensions and accuracy are demonstrated.3. We have analyzed our proposed two kinds of BSs ON/OFF strategies, and evaluted their performances in both C-RAN network architecture and integrated BSs architecture. Simulation results show that, compared to the traditional, the proposed strategies can bring higher energy efficiency in the C-RAN architecture than in traditional integrated base station architecture. Moreover, the two BSs ON/OFF strategies proposed in this thesis can effectively protect the user's service quality and reduce power comsumption simultaneously. |
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