Research On Deployment Mechanisms Of Survivable Fiber-Wireless Broadband Access Network

Big data,cloud computing and mobile Internet drive the communication technologies to develop rapidly.However,due to the lagging development,the local user terminal access network of communication networks becomes the bottleneck of last mile in the information highway.As one of the next generation promising broadband access technology candidates,Fiber-Wireless(FiWi)broadband access network can support newer multimedia services,obtain a more flexible network control,meet the demand of higher bandwidth and provide better quality of service,which benefit from the good flexibility and low cost from wireless access network and the high reliability and large capacity from optical access network.Therefore,the research of FiWi broadband access network attracts the attention of academia and industry.In recent years,the frequent outbreak of worldwide natural disasters proposes severe challenges on the deployment of survivable network.As FiWi broadband access network carrying a large amount of data,various component/fiber failures may affect huge service disruption and data traffic loss,which leading to the imponderable economic loss of operators and user terminals.Thus,how to effectively implement the deployment of FiWi broadband access network,improve the network survivability,and guarantee the continuity of data services,are becoming the focus of industry and academia.This dissertation focuses on the research of deployment mechanisms of survivable FiWi broadband access network.Combining with the typical features of FiWi broadband access network,such as various types of failures,complex structures of topologies,and variable environments of deployments,we are engaged in studying the protection deployment for single distribution fiber link failure,multiple distribution fiber links failure,joint wireless-fiber components failure,and FiWi broadband access network based on Small Cell structure,respectively.The existing problems in the current study are summarized as follows:the research on protection deployment for single distribution fiber link failure is limited;the research on protection deployment for multiple distribution fiber links failure is underutilized;the research on protection deployment for joint wireless-fiber components failure needs to be explored;and the research on protection deployment for FiWi broadband access network based on Small Cell structure remains less touched.Based on the research front of next generation survivable broadband access network,this dissertation mines the essence of problems,analyzes the current technical difficulties,and explores a series of innovative solutions aiming to solve these problems.(1)Protection deployment for single distribution fiber link failureSome research proposes the method of laying backup fibers to protect the failure of distribution fiber link.However,this protection method will greatly increase the network deployment cost.Moreover,most research considers the deployment of survivable FiWi broadband access network aiming to reduce the deployment cost of backup fiber,and ignoring the aspects of network coverage,connectivity,and delay.Thus,in the deployment process of FiWi broadband access network,this dissertation proposes using the wireless rerouting mechanism of the front end-Wireless Mesh Network,to deal with the problem of single distribution fiber link failure in the back end-Passive Optical Network.A scheme named Maximum Covering Planning with Survivability(MCPS),which aims at maximizing network coverage,is designed to solve the problems in deployment of survivable FiWi broadband access network.First of all,Integer Linear Programming(ILP)is used to model these problems and obtain the optimal solutions whilst satisfying the QoS(Quality of Service)demand in network delay,network connectivity,network cost,and network capacity,etc.Then,considering the complexity of ILP,an efficient heuristic algorithm is proposed to obtain the approximate optimal solution compared with ILP.This heuristic algorithm can complete the network deployment and maximize the network coverage under the condition of survivability requirement.(2)Protection deployment for multiple distribution fiber links failureMost of research focuses on the protection of single distribution fiber link failure,which is not comprehensive,and does not consider the problem of multiple distribution fiber links failure.Therefore,it is necessary to design the novel protection deployment mechanism for FiWi broadband access network with multiple distribution fiber links failure.First of all,this dissertation innovatively proposes a scheme named Survivability Strategies against Multi-fiber Failure(SSMF)and uses ILP model to deal with the protection deployment for FiWi broadband access network with multiple distribution fiber links failure.Moreover,in order to obtain the approximate optimal solution for a short time,a heuristic algorithm is proposed for SSMF scheme to realize the maximum coverage of network by optimizing the locations of Wireless Router(WR)and Optical Network Unit(ONU)integrated with Wireless Gateway(WG).This heuristic algorithm can verify the feasibility of proposed protection deployment mechanism for multiple distribution fiber links failure.(3)Protection deployment for joint wireless-fiber components failureRecent research mainly focuses on the protection of the back end-PON for fiber links failure,however ignores the protection of the front end-Wireless Mesh Network.In the massive disaster scenario with deployment of FiWi broadband access network,wireless links failure may occur accompanying fiber links failure,which is caused by the failures of WR.Therefore,it increases the difficulty to protect both fiber and wireless links failure in the deployment of survivable FiWi broadband access network.In this dissertation,a novel scheme named Protection Scheme with Maximal Coverage Requirement(PSMCR)is proposed to deploy and protect FiWi broadband access network with joint wireless-fiber components failure.An ILP model is established to obtain to optimal solution and provide the reference for the protection deployment of network.Moreover,in order to verify the feasibility of PSMCR,a heuristic algorithm is designed to optimize the locations of WR and configure the wireless links between WRs or ONUs.The approximate optimization of deployment and network coverage is realized.(4)Protection deployment for FiWi broadband access network based on Small Cell structureWith the rapid development of mobile traffic,mobile operators pursue a more flexible way of access,more efficient utilization of resource and more reliable management of traffic.Therefore,FiWi broadband access network based on Small Cell structure is emerged.Some references began to study the deployment of FiWi broadband access network based on Small Cell structure.However,these references only focus on minimizing the network cost.There is no research on network survivability,which is one of the elements for network deployment.Moreover,most of previous research is aimed at the scenarios of single segment failure.The complicated FiWi broadband access network with multiple segments failure also cannot be ignored.Thus,this dissertation innovatively proposes a deployment scheme for FiWi broadband access network based on Small Cell structure and designs integrated Small Cell and Wireless Router(WR)to protect intra segment failure.The constraints of network coverage,delay,capacity,and cost under variable scenarios are adopted to verify the feasibility of the proposed deployment scheme.Then,a novel complete protection scheme is proposed to overcome failures occurring in both inter and intra segments of FiWi broadband access network based on Small Cell structure.This scheme can realize the maximum network coverage by optimally placing Small Cells and splitters,whilst satisfying network survivability,delay,capacity,and connectivity requirements.As the study in deployment mechanisms of survivable FiWi broadband access network is still in the stage of theoretical research,the technological hierarchy and protocol architecture are not completed.Existing professional network simulation software such as Network Simulation 3 and OPNET does not provide the basic modules for the deployment of survivable FiWi broadband access network.Thus,this dissertation uses the professional optimization tool(ILOG CPLEX 12.1)and software VC++ 6.0 to independently develop and build the network simulation platform,and to verify and analyze the proposed protection deployment mechanisms.The entire network simulation is tested and operated on the PC with the operating system of Windows 7,CPU of Intel Xeon 2.5 GHz,and RAM of 4GB.The simulation results demonstrate that,the proposed protection deployment mechanisms have significant advantages on the aspects of ensuring business continuity,increasing network coverage,improving network deployment cost,and reducing the network delay.