Research On Energy Conservation Of Cloudlet Converged Fiber-wireless Access Networks

Integrated fiber-wireless access network(Fi Wi)has become a cost-effective deployment case that supports mobile edge computing(MEC)by combining high-capacity optical networks with highly flexible wireless networks.Because the active components of the access network account for a large part of the network infrastructure,the access network is the main energy contributor to the Internet.With the wide coverage of 5G applications,access networks will suffer from a sharp increase in energy consumption.Due to the problems of large node energy consumption and low resource utilization in Fi Wi,if new applications are to be combined with Fi Wi,network energy bottlenecks must be overcome.Therefore,the strategy of optimizing energy consumption for offload service transmission will promote the development of Fi Wi.First,this thesis discuss the background,elements and technology of Fi Wi,and then introduces the current mechanism for reducing the energy consumption of Fi Wi,which mainly includes the mechanism for reducing the energy consumption of optical networks,the mechanism for reducing the energy consumption of wireless networks,and the mechanism for energy conservation through cooperation.Secondly,a sleep mechanism for optical nodes and wireless nodes with load sensing is proposed.This mechanism controls node sleep by establishing a cooperative sleep resource management scheme,uses signaling frames to interactively obtain backlogs of service requests and Buffer backlog of cloud server,and adopts the bandwidth allocation method based on load level awareness to formulate sleep time intervals to ensure coexistence of services.At the same time,the energy consumption of the wireless node is reduced while the bandwidth is allocated,and the power of the wireless node is switched during the time slot assignment of the optical node to reduce the network energy consumption.The simulation results show that the proposed mechanism for hibernation reduces network energy costs while ensuring coexistence of services.Thirdly,an energy-saving offload mechanism based on network virtualization is proposed.The centralized controller in the virtualized network is used to separate the offload path allocation and data transmission,and establish a network energy consumption optimization model under the constraints of delay and resources.Furthermore,the wireless resources are allocated on the premise of ensuring the remaining power of the device,and the unloading link and the broadband link are combined to reduce the number of active nodes and the energy consumption of the network.The simulation results show that the proposed energy-saving mechanism for offloading effectively reduces network energy consumption while ensuring latency performance.Finally,the main work and innovations of this thesis are reviewed,and the research directions of future optical wireless access networks is discussed.