Research On Energy-saving Technology Of Base Station In Heterogeneous Cellular Network

In recent years, with the development of society, the demand of the people for communication services is increasing. For this reason, existing communications network changes the traditional and single network into stacked and three-dimensional heterogeneous cellular network. The deployment of a large number of low-power nodes on the basis of the traditional macro cellular networks can effectively resolve the problem of deeper coverage of network to a certain degree and provide better communication quality for users. However, there are some problems. The wide deployment of a variety of low power nodes increases energy consumption of network when all nodes are working at their maximum power. The distribution of users is random, and there is a typical "tides effect" in cell flow. Therefore, in the period of low load, it will bring numerous wastes of resources. At present, reducing energy consumption, reducing carbon emission and building a green communication network become hot topics of research in communication field. This paper is put forward at this technical background, according to network traffic, researching on the sleeping technology of base station for heterogeneous cellular network.(1) Firstly, we collate and summarize the concepts of heterogeneous cellular networks, and then we describe these technologies in detail. Next, we introduce the concepts and three mainly typical metrics of green communication. Finally, we summarize and analyze the existing energy-saving techniques in cellular network.(2) We study a sleep mechanism of base stations based on user connections under the scenario of two-tier macro-micro network. When the networks loads are low, the connections between users and base stations are sensed by context awareness technology. Then we use the established connection matrix to build a weighted bipartite graph. Taking the users’ Qo S and the load of base stations into account, we build a weight matrix by weighting the two as the weights of the bipartite graph. We get the optimal connection between users and base stations by constantly optimizing the value of the connection matrix. By modeling, we transform the optimization problem into a 0-1 integer programming problem and get the optimal connection by Particle Swarm Optimization(PSO) algorithm. Finally, the sleep mechanism is executed according to this connection matrix, and we achieve the goal of energy conservation by closing the base stations with low load. Simulation results show that, when the network is in low-load period. The implementation of the proposed sleep algorithm of base station can effectively reduce the energy consumption of the network, enhance the energy efficiency of the whole network, achieve energy saving targets and achieve green communications.(3) After executing sleep policy of the base stations, there will some following problems: The outage probability of network will increase, namely emerges some coverage holes; In addition, the arrival and departure of users can cause base station frequent activation and sleep. This paper introduces cell zooming to make up for the shortage. A hybrid cell compensation mechanism is proposed which combines two symmetry element compensation and the three symmetry element compensation. This mechanism does some effective compensation which put the energy efficiency as the selection basis according to the load of sleeping cells and the remaining resources of compensation cells. Simulation results show that, some cells executed the sleep algorithm through cell compensation mechanism, which caused more cells with low load to sleep, and the network outage probability is reduced in a certain degree.Through the researches and experimentations of this paper, the proposed method for energy-saving method of the base station network can effectively reduce energy consumption and achieve the goal of green communications.