Investigation On Wireless Virtual Network Embedding Algorithms

Over the last decades,it's becoming more and more difficult for existing network architecture to satisfy the continuously increasing demands of users for new better services.Network virtualization is considered as a critical technology to overcome this problem and how to allocate resources of the substrate network effectively to virtual networks is the main challenge in network virtualization which is usually referred to as VNE problem,a NP-hard problem.However,due to various features unique in wireless networks,e.g.,link interference caused by broadcast nature of links,mobility of nodes,etc.,the VNE problem becomes much more complex and harder.This thesis,in view of these two features,focuses on the VNE problem in wireless network.For the issue of link interference,a wireless VNE algorithm based on the interference weight of physic links is proposed,belonging to one-step coordinated algorithm.This algorithm selects the multi-hop network as the substrate network and adopts the one-hop interference model,quantifying the interference degree of each substrate link with the definition of interference weight which takes the link interference and available link bandwidth into account simultaneously.Substrate links with larger available resources and less interference are to map VNRs in priority.In the time window model,the VNR with larger revenue is preferred to be processed.Simulation results vividly reveal that this algorithm improves the performance of VNR acceptance ratio and increases the revenue of In Ps.With respect to the issue of node mobility,an algorithm based on the classification of mobile nodes is presented.This algorithm introduces the concept of location and mobility information for substrate nodes and adopts the RWP Mobility Model.In the node mapping stage,the mobile state and speed of substrate nodes are considered at the same time.In the link mapping stage,path splitting is introduced,aiming to improve the acceptance ratio.Once any mapped VNR is broken caused by the node mobility,fixing operation can be done according to the classification of mobile nodes in the substrate network.