Virtualized Wireless Resource Allocation Methods For Emergency Communications

With the rapid development of computer and wireless mobile communication technologies,future mobile communication networks will face the diverse scenarios challenge.Efficient emergency communication networks in natural disaster scenarios are one of the urgent requirements to be addressed.In post-disaster emergency scenarios,communication facilities such as ground base stations are severely destroyed,and the affected areas are regarded as the network island.As a result,both basic communications and rescuing communications are facing serious challenges,leading to communication failure and poor response at critical moments.Facing the key issues such as the sudden surge of diverse traffics in a short period of time and scarce spectrum resources,collaborative transmission in heterogeneous networks is a significant solution to improve the system capacity and enhance the emergency communications stability.Therefore,to meet the demands for efficient transmission of diverse traffics,this thesis integrates the wireless resource virtualization technology into emergency communication networks.An efficient resource allocation method adapted to emergency characteristics is studied,thereby improving the resource utilization efficiency of emergency communication networks.The main research contents and contributions are as follows:First,this thesis proposes a value-driven virtualized wireless resource allocation method for emergency communication backhaul networks in large-scale disaster scenarios.Firstly,aiming at the problems of matching resource inflexibly and utilizing resource inefficiently in the coexistence of heterogeneous networks,a virtualized resource slicing model is formulated to abstract heterogeneous resources into virtual resources that can be uniformly managed and dynamically allocated.Secondly,traffic-flow satisfaction utility function based on bandwidth is designed and "MatchDegree" utilized grey relational analysis is introduced.Furthermore,a dynamic parallel queuing model is established,in which the average waiting delay and packet loss are taken into consideration of emergency value.Simulation results demonstrate that the proposed scheme realizes efficient bandwidth resource allocation in emergency communication backhaul network scenarios,and outperforms the existing schemes in terms of emergency value.Second,this thesis designs and implements a virtualized wireless communication platform to verify the proposed resource allocation method.Different networks have different hardware capabilities,wireless technologies,protocols and standards.Considering that these practical problems above hinder the implementation of wireless resource virtualization,a virtualized wireless communication platform is established.Firstly,a point-to-point multimode communication is achieved using software-defined radio technology and Universal Software Radio Peripherals(USRP),and the communication process is visualized.Secondly,a virtualization protocol layer adapted to heterogeneous networks is designed,which retains the protocols of Medium Access Control(MAC)layer and physical layer in each network.In addition,universal Packet Data Convergence Protocol(PDCP)layer and Radio Link Control(RLC)layer are reconstructed to achieve parallel transmission of multi-traffic.Dealing with out of order packets caused by parallel transmission at the receiver,a better caching strategy based on Redis and hash table is proposed while traditional schemes using multi-linked list structure have much higher time complexity in reordering multi-path packets.Verification results demonstrate the validity of the proposed algorithm and validate the good performance of the platform in frequencyadaptive switching,multi-traffic scheduling,multi-traffic parallel distribution,and ultra-urgent traffic transmission.