Virtual Network Embedding Algorithm For Satellite Network Energy Efficiency Optimization

At present,with the development of aerospace technology,the number of satellites has increased sharply,and the space tasks carried on satellite networks have become more and more complex and changeable.Satellite networks urgently need to use appropriate network virtualization technology to fully utilize the characteristics of centralized control.Virtualization of multiple levels of resources,such as computing storage capacity,enables support for upper-layer multitasking dynamic reconfiguration capabilities.Network virtualization is an important technology for future network development.How to map virtual networks on physical networks is the main resource allocation problem faced by network virtualization.Therefore,virtual network embedding technology is a key technology for network virtualization.The community has also proposed a lot of research results on this technology,but these technologies are based on the ground network to build the network model,which cannot adapt to the underlying network environment of satellite network topology which is dynamic,resource scarce,and has special constraints demand for services.This paper combines the characteristics of satellite network’s link establishment and topology changes,improves on the original virtual network embedding algorithm network model,and adds concepts such as setup time,energy loss,and service interruption to reasonably analyze the satellite network related characteristics.A special network model of satellite network is established,and the performance evaluation standard of satellite network virtual network embedding algorithm is proposed.Combined with the special network model of satellite network,two kinds of virtual network embedding algorithms for satellite network energy efficiency optimization are proposed:a virtual network embedding algorithm to save satellite energy consumption(ES-VNE)and a satellite energy-saving virtual network embedding algorithm to reduce service interruption(RES-VNE).(1)Virtual network embedding algorithm to save satellite energy consumption aims to address the problem of satellite network embedding virtual network requiring additional satellite energy consumption.It considers the physical node CPU resources and the status of surrounding links during the node mapping phase,and considers the physical link bandwidth resources and link establishment status in the link mapping phase.Without causing network bottlenecks,ES-VNE increases the mapping on the established physical links,reduces the link establishment time caused by each mapping,reduces the additional energy consumption caused by virtual network mapping and reduces the idle time of physical network resources while waiting for other physical resources’establishment.What’s more,ES-VNE improves the acceptance rate of satellite network virtual network requests.(2)Satellite energy-saving virtual network embedding algorithm to reduce service interruption aims to address the problem of virtual network interruption caused by satellite network dynamics.It considers the periodic dynamic movement of satellite nodes and proposes the concept of physical link lifetime to the satellite network model.By adjusting the virtual network mapping process,the resource pool is pre-processed before the virtual network mapping calculation is performed to exclude the physical resources that will expire within the request lifetime.A resource view is customized for each request.According to the simulations,the ES-VNE and RES-VNE reduce the physical link’s establishment process,which can effectively reduce energy consumption by about 20%compared with the two-step algorithm,increase the acceptance rate of satellite network virtual network requests by up to 25%if virtual networks with small bandwidth requirements and large CPU.What’s more,RES-VNE can reduce the number of satellite network service interruptions by more than 99%on the basis of reducing energy consumption and increasing the request acceptance rate.