Heterogeneous Network Based Traffic Offloading Scheme

With the rapid development of mobile Internet,the number of smart mobile terminals is growing rapidly.Mobile data traffic is also growing exponentially.This poses a great challenge to exist cellular networks.On the one hand,the existing base station facilities can not meet the huge traffic needs.On the other hand,in order to provide a wireless service in accordance with the needs of the user,base station construction,maintenance,and other costs are increasing.These problems have seriously hampered the vigorous development of mobile Internet trends.Heterogeneous cellular networks are considered to be pragmatic and cost-effective approach to significantly enhance the capacity of LTE cellular networks.The suitable mobile service offloading solution based on heterogeneous cellular network can greatly solve the overload problem,optimize the energy consumption and improve the system capacity.Small cell access points can offload macro cell services,improve indoor coverage and cell edge user performance,and increase network capacity.In this paper,we focus on the study of traffic offloading scheme,considering the following three scenarios: 1.The traffic offloading scheme between two mobile network operators is introduced;2.The traffic offloading scheme aiming to minimize the total power consumption of base stations with the dualconnectivity is proposed;3.The flow control and resource allocation scheme based on various wireless service is proposed.For the first scenario,offloading between two mobile network operators is considered.Overloaded operator's base station serves too many users leading poor user service quality.At this time the small base stations have been fully loaded or the operator even have no small base stations.Overloaded operators seek other operators of the relative free base station for user offloading,so as to ensure user quality of service.In this section,we formulate a two-layered game to explore the effect of operators on resource allocation and revenue sharing.Two operators achieve a win-win situation finally.For the second scenario,we study the energy saving optimization of base station when the quality of service meets the demand under dual-connectivity technology.The mobile terminal has multiple radio-interfaces,which greatly facilitate dynamic traffic offloading.Users can access the wireless service activates two radio-interfaces simultaneously,which means a base station's traffic offloaded to other base stations.On the one hand,saving the base station wireless spectrum resources,on the other hand,the base station energy consumption is saved,and the service quality of the user is ensured.In this paper,by optimizing the energy consumption of the base stations,the aim is to find the optimal resource allocation and power control scheme.At the same time,through the decoupling factor of artificial structure,the traffic allocation relationship of dual-connectivity users between two base stations is explored.In this paper,two algorithms are proposed to solve this problem.For the third scenario,the wireless service is divided into two different types of service.The first type of service is fully guaranteed.The second types of services are obtained by dynamic spectrum access to other base stations.In this paper,we construct a stochastic optimization problem to obtain the traffic control and resource allocation scheme,so as to guarantee the stability of the first class of services while obtaining the largest second class of services.This paper uses the queue model to guarantee the long term stability of first class of services.An online algorithm requiring just current information of queue state and channel state instead of statistics information is proposed.