Attractor Based Heterogeneous Multiple Access Network Selection Strategy

With the rapid development of wireless communication network technology,the increasing of data traffic,the business and the terminal number makes the development of the next generation wireless communication network tend to be heterogeneous and coexistence of multiple networks.Therefore,how to optimize the existing heterogeneous network resources,dynamically select a reasonable and effective access network strategy,reducing transmission delay,improving the overall performance and service quality of the system have become an urgent problem to be solved in heterogeneous wireless networks.This paper proposes a new heterogeneous wireless network(P-HN),including WiFi network,cellular network and power line carrier communication(PLC).Based on the P-HN,this paper focuses on how to solve the problem of multi-access networks selection.Firstly,in order to improve the network throughput and ensure the reasonable distribution of network load,a traffic offload strategy based on attractor algorithm is proposed.Secondly,in order to reduce the transmission delay of the network and ensure the reliability and robustness of the heterogeneous network,the attractor selection strategy based on queuing delay is proposed.Finally,a priority based attractor network selection strategy is proposed to guarantee the service priority requirements and enhance the reliability and robustness of the network.The main contributions and research work of this thesis can be summarized as follows:1.The Design of the P-HN architectureAiming at the problems of low integration in heterogeneous wireless networks and long transmission delay,a novel network is proposed with the advantages of PLC,which integrates the PLC and wireless networks(P-HN).Firstly,the existing architecture and the access management model of the heterogeneous networks are studied and analyzed.Based on this,an Effective Virtual Layer(EVL)is added to the standard frame of the traditional data transmission.The emergence of the EVL has the function,in which P-HN can transmit data seamlessly with the different access technologies.The simulation results show that P-HN can effectively reduce the transmission delay and improve the performance of the system under the same experimental environment.Thus,P-HN can reduce the no-signal areas of heterogeneous networks and extend the coverage of the network.Moreover,this thesis applies an adaptive path selection algorithm based on biology to solve the problem of network selection in P-HN.Firstly,based on the adaptive algorithm of biology,the thesis maps the parameters and variables,which is used in the biological algorithm to the communication system(P-HN).Then,the adaptive network selection strategy named Residual bandwidth based Attractor Selection Strategy(RASS)is obtained,which can adaptively select the optimal network to transmit data according to the residual bandwidth.Finally,simulation results show that P-HN based on RASS can reduce the transmission delay and improve the robustness of the system compared with the single transmission network.2.Traffic Offloading Scheme in P-HNIn order to solve the problem of the Non-uniform distribution of traffic and the decrease of system throughput in traditional traffic offloading network,the traffic can be offloading through WiFi or Femtocell networks in the heterogeneous networks.Similarly,the PLC network can be applied for traffic offloading from the Operator's perspective.In this thesis,an adaptive traffic Offloading strategy based Attractor Selection Strategy(OASS)in P-HN is proposed.Firstly,aiming at improving the system throughput and the coordinating traffic distribution in the cellular,a traffic offloading model based on P-HN is proposed.Secondly,the throughput of the cellular and the PLC network are considered jointly to find the optimal offloading ratio.The simulation results show that the adaptive strategy takes the offloading ratio as the parameter,which can solve the problem of Non-uniform distribution of traffic effectively.Thus,the network throughputs are improved.3.Adaptive Selection Strategy based Queuing DelayIn order to solve the problems of poor flexibility and complex compulation of existing network access selection algorithms,a delay based attractor selection strategy(DASS)is proposed in P-HN.Firstly,the two networks queuing model in P-HN is proposed to select the shortest queuing delay network.Secondly,the queuing delays of the two networks are obtained by the second-order Markov chain.Then,the two networks queuing model is extended to the multi-network queuing model.The solution set of the network delay is obtained by the multi-order Markov transmission state equation.The simulation results show that the node can select the network to transmit data with the least delay.And the system still guarantees a large transmission ratio while the node failure occurs in the system.4.Priority Based Adaptive Selection StrategyAiming at the existing access network selection strategies cannot dynamically the guarantee of the different priotiry requirements of various user services in real-time,a resource optimization strategy based on the users' priority satisfaction is proposed.Firstly,considering the QoS of applications,this thesis classifies the transmission data based on the priority,and the priority scheduling model are established to ensure the transmission requirement of the high priority users.Secondly,the queuing model for two networks with the multi-priority data is established.The mathematical characteristics of this model are described by establishing a 3D Markov chain.Finally,the delay of the users with the different priority networks are matched with the adaptive network selection algorithm named PASS.Both the theoretical analysis and simulation results draws that strategy has good adaptability in both the mobile and the fixed scenarios.And it reduces the transmission delay of the network and guarantees the QoS of the applications.