Investigation On Wireless Virtual Network Embedding Algorithms

Network virtualization is an important support technology of the future development of the Internet,which aims to overcome the resistance of the current Internet on the structural changes.With the rapid development of wireless communication technology and the continuous emergence of various mobile services,wireless network virtualization technology has become very important.This thesis mainly studies one of the key issues in wireless network virtualization-virtual network mapping,that is,how to map the virtual nodes and virtual links in the virtual network to the underlying physical network efficiently and reliably.Based on the existing mapping algorithms,this thesis will propose two more efficient and reliable virtual network mapping algorithms.In view of the adverse effect of traditional greedy node mapping,a new node ranking method is proposed according to the topological attributes of wireless network nodes,which makes the node resource evaluation more specific.Topological properties come in diverse forms and measure the relative impact or importance of nodes from different perspectives.By using the advantages of the node topological properties,three topology-aware heuristic algorithms with multiple features are proposed,and then compared by simulation.The algorithm considers not only the resource requirements of the nodes,but also their topology properties to better coordinate the node and link mappings.The simulation results show that the algorithm considering more topological features of nodes performs better in terms of performance,such as the acceptance rate and the income.Since the existing virtual network mapping algorithms are mostly based on a fault-free network environment,the survivability of the mapped virtual network is not considered.In view of the survivability of the virtual network mapping algorithm in wireless environment,this thesis proposes a proactive path-based survivability algorithm.The algorithm considers the availability requirement constraint on the link for the link failure problem.By evaluating the link availability,it provides a backup path for the path that needs the link backup,which effectively reduces the utilization rate of the bandwidth resource and increases the acceptance rate of the VNR.To some extent,the survivability of virtual network mapping is guaranteed.