Research On Dynamic Energy Management Algorithms For Base Station Based On Lyapunov Optimization

With the rapid development of mobile Internet and the drive of new mobile devices,mobile data traffic is growing explosively,which leads to a large amount of energy consumption and accompanying carbon footprint,at the same time,it results in high energy cost for the cellular networks operators.Energy harvesting(EH),an emerging technology,is used to harvest energy from the surrounding distributed renewable energy sources as an environmentally friendlier supply of energy for the cellular networks,the EH technology can reduce the use of traditional energy in cellular networks and the accompanying carbon dioxide emissions,the energy costs effectively for cellular networks operators.However the energy harvested from the natural environment is always intermittent and random energy consumption in the cellular networks while ensure its reliable operation,the hybrid energy sources mode of the EH source and the power grid in a complementary manner becomes an attractive solution.In this paper,we study the problem of dynamic energy management for the cellular networks supplied by hybrid energy sources,which includes smart grid and renewable source,with the aim of decreasing the use and cost of non-renewable energy.The new features of smart grid,such as time-varying electricity price,etc,is fully considered,and the basic model of EH base station with the smart grid is constructed.The Lyapunov optimization is used to design the general energy management algorithm EH base station under the condition of unknown EH process,energy demand and time-varying electricity price.Based on the above proposed model energy cooperation model of multiple EH base station is constructed,and the real-time energy cooperation algorithm between base stations is designed to reduce the traditional energy consumption and energy cost in the cellular networks,and improve the environment.This study can promote the development of the green cellular networks.The specific work is as follows:1.Firstly,the latest status of energy management research in the field of communication is analyzed and summarized.The EH technologies involved in EH cellular networks are introduced in detail,including the classification and energy model of the technologies.The related theoretical knowledge of queues involved in the energy random arrival model is introduced.Finally,the research methods of energy management are introduced respectively for the known EH model and the energy random arrival model,which provides a theoretical basis for the research of energy management of EH base station in cellular networks.2.The base station model and dynamic energy management scheme of the EH base station powered by the smart grid with time-varying price is studied.Smart grid is used as a supplement of energy to ensure the stable operation of base station.Considering the EH,energy demand and time-varying electricity price are all general stochastic processes(unknown probability distribution)and limited battery capacity,EH base station model of smart grid is added as energy supplement.A dynamic energy management algorithm is proposed utilizing Lyapunov optimization to minimize the energy consumption cost of base station under two conditions: inelastic energy demand and elastic energy demand.This algorithm considers the scheduling problem of obtaining energy from different energy sources,and decides how much energy storage to buy from smart grid in real time according to electricity price and current status,thus reducing the energy cost of base station.The validity of the algorithm is theoretically analyzed and verified by simulation at last,and the effect of battery capacity on the performance of the algorithm is analyzed.3.Based on the above single base station model,the energy cooperation model and real-time energy cooperation algorithm of multiple EH base stations are studied.Considering the difference in EH caused by the geographical location of the base stations,the purpose and the capabilities of each base stations are different as well as the capacity of the energy storage battery is limited,and the base stations of the same mobile operator(such as China Mobile or China Unicom)is constructed.The cooperative model of sharing EH energy with each other,according to the state of each base station,including EH,energy demand,reserve energy,loss of energy sharing and current electricity price of smart grid,a real-time energy cooperation algorithm for base stations inelastic energy demand and elastic energy demand is proposed utilizing Lyapunov optimization.To minimize the sum of the energy cost from the smart grid and to improve the utilization efficiency of the energy harvesting,the validity of the algorithm is theoretically analyzed and verified by simulation.Meanwhile,the influence of the transmission efficiency and the capacity of the battery on the performance of the algorithm is analyzed.