Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-10-11 Cooperative journals: 《计算机应用研究》
Abstract: In the 5G mobile communication network virtualization scenario, a redundant backup method is usually adopted in order to ensure the reliability of network services. To reduce the cost of backup resources, first, by ordering the Backup-Cost Importance of the virtual network functions, this paper makes a joint backup of virtual network function with the largest and second largest Backup-Cost Importance in each iteration, and obtain the optimal backup strategy through the corresponding selection and update model. Finally, the method is compared with other three methods, the proposed method has better performance in the backup cost, the amount of used physical node, the number of accepted service requests and backup resource utilization.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-20 Cooperative journals: 《计算机应用研究》
Abstract: In the 5G mobile communication network virtualization scenario, how to deploy network slices safely is a prerequisite for future large-scale commercial use. Aiming at the security of 5G network slice deployment, this paper proposed a strategy for network slicing deployment based on security trust. The deployment strategy could effectively quantify and analyzed the security of VNF and network resources by proposing the concept of security trust value, and on this basis, constructed the mathematical model of network slice deployment using 0-1 integer linear programming method. The strategy used heuristic algorithm to find the minimum cost of network slice deployment. Simulation results show that the deployment strategy reduces the deployment cost and achieves better security revenue and deployment rate of return under the premise of ensuring the deployment security.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-20 Cooperative journals: 《计算机应用研究》
Abstract: To solve eavesdropping problem in multi-relay successive relaying systems, this paper proposed a security-oriented relay selection schemes. First, it proposed optimal relay selection (OPRS) scheme through general search and deduced theoretical secrecy rate. To lower complexity, two different two-stage relay selection schemes which proposed first narrows the scope of relays from aspects of decreasing computation complexity and CSI overhead, respectively. Simulation results show that K-MMRS scheme can achieve optimal secrecy rate with lower complexity.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-02 Cooperative journals: 《计算机应用研究》
Abstract: Aiming at the reasonable placement of different business contents in content centric networking (CCN) , this paper proposed a hybrid caching scheme based on service classification and node partition (SCNP) . For streaming media-on-demand services, this scheme used push-pull cache strategy based on popularity to achieve its sequential storage in the edge network. For non-streaming contents, this scheme used hash-based explicit cache strategy to implement its placement of single copy in the core network. Simulation results show that compared with the classic cache algorithms, this scheme can improve the cache hit ratio and the hop reduction ratio, and reduce the average request delay.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-02 Cooperative journals: 《计算机应用研究》
Abstract: There are some problems on multi-user downlink power allocation and beamforming in a cognitive radio network (CRN) which works in the underlay mode. They are the high complexity of the conventional SDR algorithm, the limited applicability and ignoring the interferences of the primary network (PN) to the secondary user(SU), etc. Aiming at these problems, this paper firstly added the term of interference of the PN to the SU to the CRN model and formulated the optimization problem. Then based on the duality of uplink-downlink, it obtained the simple and fast iterative algorithm by introducing virtual power, transforming the optimization problem into the problem of uplink power allocation and beamforming. And it analyzed the convergence of the algorithm to obtain the convergent conditions. It also reckoned the algorithm complexity. The result demonstrates that iterative algorithm is superior to the SDR algorithm. Numerical simulation results show that the algorithm converges faster, and that the variation of transmitting power of the primary base station (PBS) could affect the feasibility region. They also show that the increasing of transmitting power of the PBS could lead to the downlink power increasing. The influences are notable.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-02 Cooperative journals: 《计算机应用研究》
Abstract: 5G mobile communication network hire more data centers of infrastructure provider to cooperate to construct network section, Aiming the efficiently cross domain virtual network mapping which is a key problem in network lifecycle management in network slice, proposeda two stage cross domain mapping strategy, DPSO-K. Firstly, based on the resource bidding, considered the resource of nodes and the bandwidth between domains, and proposed a optimized discrete particle swarm optimization (PSO) algorithm for inter domain virtual network mapping, which can effectively improve the searching ability; then, proposed a fast algorithm based on Kruise Karle minimum spanning tree to reduce the cost of intra domain mapping, which reduces the time of fragment instantiation and shortens the on-line speed of service. The comparing to the traditional method of the first virtual network mapping request division unified mapping link, the strategy considered the bandwidth overhead in the request division, and payed attention to key link in mapping mapping link, mode of centralized management, distributed control, to realize the effective use of physical and cyber source. Experimental results show that this algorithm can achieve higher acceptance rate with less overhead and less partitioning time.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-24 Cooperative journals: 《计算机应用研究》
Abstract: By utilizing the characteristics of resource sharing in cloud computing, attackers can launch DoS attack by constantly consuming bandwidth resources so that other users on the same physical host can not receive normal services. This attack mode is different from the DoS attack in traditional network system, so it is difficult to apply traditional defense method to solve it. To solve this problem, this paper proposes a DoS attack defense method based on virtual machine migration. By selecting the migration target, designing the triggering mechanism and selecting the migration destination, a virtual machine migration strategy is proposed to mitigate the impact of DoS attacks. The experimental results demonstrate that this method can effectively defend DoS attack and ensure the normal operation of cloud service whatever different attack methods that attackers may use. Compared with other methods, the proposed strategy leads a litter more migration cost, however, it’s better in defense effect and feasibility.