The Research On Key Technologies Of Heterogeneous Networks Convergence

With the dramatic development of mobile devices and communication technology,the new services such as virtual reality,wireless cloud computing,autonomous driving,M2M(Machine-to-Machine)and Io T(Internet of Things),have been provided in a vast range of use cases,and will bring great challenges to the coverage,load,bandwidth and latency of existing communication networks.To further enhance the latency and broadband experience for customers in these new services,it requires a generational shift in communication technology.The future network is a hybrid overlapping heterogeneous network,the covering range of WAN(Wide Area Network)is usually large and with limited transmission bandwidth.On the contrary,the LAN(local area network)has small coverage and with high bandwidth.Because the complementary features of heterogeneous networks(Het Nets)and each heterogeneous network have advantages and disadvantages,Het Nets has been deployed as an effective and popular means to the evolutions of existing Internet for the services.Firstly,in this article,we present a series of network architecture for Het Nets,including IEEE 802.21 MIH,3GPP-WLAN interworking in EPC and radio level,OMEGA Inter-MAC Layer and IEEE 1905.1 Abstraction Layer.Based on these architectures or protocols,we present a novel and practical Inter-MAC architecture for Het Nets,which unified Ethernet technology and non-Ethernet technology in the form of a middleware.The architecture provides a common extensible network access interface for the lower heterogeneous access networks,and mapping between the Inter-MAC interface and the underlying networks MAC interface.The Inter-MAC layer supports MAC frame switching and link scheduling,including topology discovery module,authentication module,bridge module,protocol adaptation module,interface configuration module,link scheduling module and link multiplexing module.Secondly,the key to the vertical handover(VHO)is to ensure service continuity and to reduce the number of handover.On the one hand,traditional multi-attribute function algorithms can lead to frequent handover;On the other hand,the centralized optimal VHO algorithm and MDP-based handoff method can realize the optimal network select,but it is difficult to implement in the real system because of its complexity and computing overhead.In this paper,we propose a novel VHO algorithm based on service history information.The algorithm establishes the membership function of the service history information,the received signal strength(RSS),the remaining bandwidth(load),the speed,the cost and the Qo S(Quality of Service)parameter.And the non-Qo S parameters adopt dynamic weights to adapt to the changes of network.For the service history information,the proposed algorithm constructs the corresponding segment membership function with the blocking time interval and the cumulative service time,accurately modeling the historical access information of different business types.Simulation results show that the proposed VHO algorithm outperforms existing VHO algorithms.Finally,it is common for future Het Nets to employ Multi-Radio access technologies to meet the requirements of the quality of services,and as well to improve the system performance.The traditional Multi-Radio resource allocation algorithm usually ignores the user's Qo E(Quality of Experience).Therefore,we propose a Qo E-based resource allocation algorithm for Multi-Radio heterogeneous networks.The algorithm uses Qo E utility function to establish the optimal resource allocation model of bandwidth and power.And the utility function is defined by function multiplication method.To obtain the optimal solution of the model,we apply the gradient projection method to solve it.Simulation results show that the proposed scheme can maximize the users' Qo E utility subject to the constraints of transmit bandwidth,power and data rate.