最新刊期
卷 31 ， 期 8 ， 2015
- 摘要：Firstly，the concept of SDN applications was proposed from the perspective of users payment for allocating network resources.Secondly，with the comparison between traditional desktop application programming and network programming，the advantage of SDN programming was described.Thirdly，the concept of software defined price （SDP）was introduced.Based on the characteristics of SDN applications，the framework of SDP-based SDN application so as to apply to the OpenDaylight open source project was designed.Finally，an implementation of creating a virtual tenant network based on SDP was showed.The results of experiment present that the users can choose their desired virtual tenant according to the mechanism of SDP.关键词：SDN;SDN application;software defined price;virtual tenant network1077|1593|0更新时间：2024-06-05
- 摘要：Considering the inevitable trends for heterogeneous network convergence and self-adaptation ability，cognitive radio network（CRN）concept has been proposed with some essential characteristics to achieve global endto-end goals.CRN are composed of cognitive devices which have the capable of changing network configurations based on the dynamic environment.This capability opens up the possibility of designing flexible and dynamic topology control strategies with the purpose of opportunistically reusing idle licensed spectrum and effectively achieving data transmission.This work focuses on the problem of designing effective topology reconfiguration algorithm to offer optimal routing solutions.关键词：cognitive radio network;reconfiguration;topology;heterogeneous network convergence911|1231|0更新时间：2024-06-05
- 摘要：Aiming at the path cycle and source address binding problem in middlebox service chain deployment，a service chain deployment approach by combining the OpenFlow mechanism and NetFPGA was proposed.First of all，the OpenFlow multi-flow table was used for marking service chains and labeling service sequences so that data packets could be processed correctly according to desired service order；secondly，the service chain deployment algorithm was designed to achieve the mapping relationship between the service path and flow table rules；thirdly，a prototype system was implemented based on the hardware platforms of NetFPGA-10G.Finally，experimental results show that the proposed method have the advantage of feasibility and outperforms compared methods in the aspect of the flow table number and time overhead.关键词：software defined networking;middlebox;service chain;multi-flow table796|982|0更新时间：2024-06-05
- 摘要：In view of the problem that current algorithm mainly research on topology construction or topology maintenance separately，a topology control algorithm based on two processes combined was proposed，which was adaptive to the network with heterogeneous communication and energy.Topology construction was to construct connected dominating set with low message overhead，and topology maintenance was to execute local or global repair strategies by sink node based on time，energy or failure mechanism to save energy.Theoretical analysis and simulation experiments confirm that the algorithm can construct topology with low time and message overhead and extend network lifetime.关键词：wireless sensor network;energy supply;topology control;topology construction;topology maintenance500|996|0更新时间：2024-06-05
- 摘要：The optimization problem of joint beamforming and power for cognitive MIMO system was studied.Firstly，a non-cooperative separable game model was established and a cost function about the two parameters was put forward.Then it was concluded that the optimal Nash equilibrium of joint game exists by proving the existence of optimal Nash equilibrium of two sub-games through KT conditions.Finally，a new iterative algorithm alternately was presented.The simulation results demonstrate that the proposed algorithm has a faster convergence rate.Meanwhile，the algorithm also comes to the optimal Nash equilibrium and has perfect stability in the dynamic communication environment.关键词：cognitive radio;MIMO;game theory;beamforming，power440|1110|0更新时间：2024-06-05
- 摘要：Granger causality existed between traffic at different access points of large-scale wireless LANs was discovered.The Granger causality illustrates that the historical traffic of access points that exist causality within target access points help predict the future of target access points with better accuracy than when considering information from the past of target access point alone.Bayesian network to model the causal relationship between access points and adopted a Gaussian mixture model（GMM）was used，as well as a weighted combination of several normal distribution functions in order to approximate the joint probability distribution in Bayesian networks.Finally，the traffic data in large-scale wireless LANs was imported，having hundreds of access points，to verify the accuracy of the proposed method，and a processing flow of analysis，modeling and prediction of traffic flow data was established.关键词：WLAN;traffic prediction;traffic characteristics;Granger causality;Bayesian network742|1482|0更新时间：2024-06-05
- 摘要：To improve the vacant spectrum utilization，ultra-wideband spectrum sensing is critical for cognitive radio （CR）as it enables secondary users to dynamically access the unoccupied spectrum bands.However，the fast and accurate spectrum sensing is still a challenge over an ultra-wide bandwidth in low signal to noise ratio（SNR） environment.A compressed sensing （CS）-feature detector based on wavelet de-noising was proposed to perform wideband detection in low SNR.CS was proposed to improve the efficiency of wideband spectrum sensing.And two dimensional wavelet transform was introduced to deal with the noise in spectral coherence function（SCF）by the CS process.As a result，the detection accuracy in low SNR was improved.It is found that the proposed technology can detect spectrum holes at a range of low SNR through simulation results.关键词：compressed sensing;cyclostationary feature detection;wavelet de-noising455|1154|0更新时间：2024-06-05
- 摘要：Traditional fractional frequency offset（FFO）estimation algorithm pay less attention to FFO polarity estimation.Noise and channel fading induced FFO estimation polarity reversion degrades the frequency synchronization performance inevitably.An efficient FFO polarity detection method was proposed in LTE-Advanced system to solve the problem，which utilized the mirror symmetry property of time-domain primary synchronization signal（PSS）.Numerical results show that the proposed method can depress FFO polarity reversion efficiently.关键词：frequency synchronization;polarity reversion elimination;LTE-Advanced;downlink;fractional frequency offset449|788|0更新时间：2024-06-05
- 摘要：An algorithm called LSHSM，which uses locality sensitive hashing（LSH）to process time subsequence matching，was proposed.Different to the FRM and DualMatch algorithms，the LSHSM does not require feature transformation such as DFT and DWT.It just directly regards the sequence as a high-dimensional object to find similar subsequences.Comparing to a linear algorithm on three real datasets，the LSHSM algorithm demonstrates the effectiveness and efficiency.关键词：time subsequence;locality sensitive hashing;match searching531|1294|0更新时间：2024-06-05
- 摘要：By using the statistical average results of higher-order powers of Gaussian Q-function in multi-branch diversity reception with maximum ratio combining（MRC）in Rayleigh fading channel，exact closed-form for the average symbol error rate（ASER）of differentially encoded quadri-phase shift keying（DE-QPSK）using coherent detection with transmit selection combining（SC）and receive MRC（SC/MRC）in Nakagami fading channels was derived.Approximate closed-form for the ASER of DE-QPSK with SC/MRC in Nakagami fading channels was derived by using the approximate expression of Gaussian Q-function and moment generating function based analysis approach.Numerical and simulation results show that the theoretical analysis of the ASER of DE-QPSK is exact and the approximate closed-form for the ASER of DE-QPSK is accurate.The above results can be used to design SC/MRC antenna diversity systems with DE-QPSK.关键词：Nakagami fading channel;selection combining;maximal ratio combining;differentially encoded quadric-phase shift keying;symbol error rate362|804|0更新时间：2024-06-05
- 摘要：Comparing with traditional support vector machine，hyperplane support vector machine （HPSVM）and hyperplane support vector machine for regression（HPSVMR）not only reduce the number of support vectors and calculation time but also have comparable accuracy.However，they have different simplification effect on different problems.The reasons for this phenomenon were analyzed，the conclusion that the lower the percentage of non-bound support vectors is，the more obvious the effect of simplification was pointed out.关键词：pattern recognition;hyperplane support vector machine;reduced support vector machine;performance analysis464|898|0更新时间：2024-06-05
- 摘要：A new transmission mechanism called direct and relay-aided transmissions based on inter group cooperation was proposed for the cognitive radio network.The performance of a single-relay system based on amplify-forward in the Rayleigh fading environment by considering the interference constraints and peak power constraints was analyzed.The impact of the relay node and the primary users（PU）location on power allocation and system throughout was investigated and the performance of the optimal power allocation（OPA）scheme and equal power allocation（EPA）scheme was compared.The result shows that the locations of relay node and PU are crucial to the system performance and the proposal optimum power allocation scheme significantly outperforms the equal power allocation scheme.The best performance was achieved when the relay is at an equal distance from the sender and the destination in EPA scheme or the relay is closer to the destination around in OPA scheme.关键词：cognitive radio network;power allocation;relay location;direct and relay-aided transmissions369|948|0更新时间：2024-06-05
- 摘要：In order to minimize resource provisioning cost of commercial cloud center，while guarantee percentile response time SLA，a cloud center model based on queuing theory was proposed.Resource provisioning cost was analyzed from an economic point of view，and the mathematical expressions of cloud center percentile response time were deduced.Meanwhile the minimum provisioning cost algorithm（MPCA）was developed to calculate the minimum cost of cloud center，the affect on cloud center cost by load flow，percentile response time and based response time was analyzed via a large number of experiments.The results show that with MPCA to optimized server number and speed of cloud center，it can achieve cost linear increase with increasing traffic load.关键词：percentile response time;cloud center;resource provision;SLA390|782|0更新时间：2024-06-05
- 摘要：In order to make full use of the resources of all kinds of wireless network，the integration of heterogeneous network is necessary.However，when it comes to the heterogeneous network integration，the problems of call request access control and resource management emerge.A reinforcement-learning-based algorithm was presented for heterogeneous wireless network resource management.D2D （device-to-device）communication was introduced into the proposed algorithm and the appropriate network for access could be selected according to different traffic types，terminal mobility，network load status and so on.Meanwhile，to reduce the storage requirement，the neural network technology was used to solve the problem of continuous state space.Simulation results show that the proposed algorithm has an efficient learning ability to achieve autonomous radio resource management，which effectively improves the spectrum utility and reduces the blocking probability.关键词：heterogeneous wireless network;access control;resource management;reinforcement learning;Q-learning614|1596|0更新时间：2024-06-05
- 摘要：Two independent frequency bands are used for half duplex radios to realize simultaneous transmission and reception.Recently，full duplex radios are allowed to transmit and receive data packets simultaneously in one frequency band.To improve the performance of full duplex radio networks，a novel MAC protocol called FD-MAC for full duplex radio networks，which was a simple and efficient protocol compatible with standard IEEE 802.11 MAC protocol，was proposed.By taking both the physical layer and MAC layer into account，the performance of full duplex network with FD-MAC was analyzed.The analytical and simulation results demonstrate that，compared with the existing MAC protocols for full duplex radio，FD-MAC protocol owns a higher network throughput performance and a lower power consumption.关键词：wireless network;full duplex;IEEE 802.11 MAC protocol;throughput;delay471|753|0更新时间：2024-06-05
- 摘要：Considering the frame structure of IEEE 802.11ac with “leading preamble plus comb-like pilot”，the performance evaluation formula of the correction scheme based on maximum likelihood estimation was derived，according to which the effect of pilot location，channel fading and subcarrier correlation was studied.Furthermore，a signalling exchange method was proposed，which ensured pilot position synchronization on both end，and a low complexity algorithm of pilot optimization according to the frequency channel amplitude information.In this way，the pilot overhead can be reduced without loss of correction performance.The experiment and simulation result shows that for ideal Rayleigh channel data，correction performance improves by 1.85 dB and 7.15 dB for unknown channel amplitude information in frequency domain and known cases respectively.For field experiment channel data，correction performance improves by 1.67 dB and 2.68 dB respectively.关键词：WLAN;frequency offset correction;phase noise compensation;pilot optimization333|766|0更新时间：2024-06-05
research and development
- 摘要：The historical development，traffic characteristics，potentials and challenges of machine type communications（MTC）were introduced.A comprehensive survey on the traffic modeling and access control for the concurrent data transmission from massive MTC devices was made.With the recommendations on traffic engineering suggested by International Telecommunication Union （ITU）and International Teletraffic Congress （ITC），some important issues and key problems in the fields of traffic characteristics analysis，traffic modeling and access control for MTC were summarized，in order to provide engineers and researchers insights on the improved performance analysis and enhanced access control for carrier network，which would promote the deployment and standardization of MTC and internet of things.关键词：Internet of things;machine type communication;traffic modeling;access control547|1026|0更新时间：2024-06-05
- 摘要：Smart IoT devices go into product stage from hype stage.Sensors are being miniaturized，integrated，intelligent and diversified，turn the reality into digital.IoT device’s intelligent is based on power of processor and advanced operation system，and be enhanced by the cloud computing and big data.As smart phone，the smart IoT devices need to build an active ecosystem that engage developers to innovate.The several key technologies development status and future trends were explored，analyzed，and displayed.关键词：intelligent IoT device;sensor;ecosystem831|2187|0更新时间：2024-06-05
summarize
- 摘要：Compared to traditional network，the network structure has a greater impact on the quality of TD-LTE network.If only upgrade directly in the original site based on TD-SCDMA，the original structure and quality issues would be inherited.On the basis of the problems encountered in the shared antenna collaborative optimization，a collaborative network optimization method was presented.Network problems of TD-SCDMA and TD-LTE were solved from the dimensions of network structure，coverage and interference by using project parameters，measurement report，frequency sweep test，driving test and other data.After that，by using network planning and optimization tools，collaborative optimization scheme was outputted and verified in the existing network to solve these problems.Finally，TD-SCDMA and TD-LTE collaborative optimization adjustment strategy was summed up by evaluating implementation effects.关键词：TD-LTE;TD-SCDMA;shared antenna;network optimization;collaborative optimization553|1176|0更新时间：2024-06-05
- 摘要：MEF Carrier Ethernet（CE）2.0 has been widely concerned and supported by international major telecom service providers.It has become new generation standard of Ethernet service interoperability and transparent management.By researching MEF CE 2.0 related standards，methods and key technical details in depth，related service definition，operation flow，network topology，test items and practical application of CE 2.0 authentication testing were summarized.关键词：MEF 2.0;Ethernet service;certification test566|1283|0更新时间：2024-06-05
- 摘要：LTE of mobile communications has been fully opened.In the stage of LTE，BBU’s centralized deployment can effectively reduce the difficulty of development for base station sites，lower down CAPEX/OPEX and achieve rapid network construction，thus rendering large-scale application of the situation.Firstly，the requirement of CPRI link for BBU centralized deployment was introduced.Secondly，several possible solutions for carrying CPRI link were described.Finally，the application recommendations through comparison and analysis were presented.关键词：common public radio interface;centralized BBU deployment;wavelength division multiplexing196|572|0更新时间：2024-06-05
- 摘要：As the guarantee of cloud security，user identity authentication is crucial to cloud computing.In this work，the requirements of security authentication in the current cloud service systems were analyzed.Considering the principle and the advantages of fingerprint recognition，a novel system based on fingerprint recognition was proposed for cloud security authentication.The architecture and workflow of the proposed system were investigated in depth to prevent the unauthorized access，achieving the secure access of user data for cloud services.关键词：cloud computing;cloud security;fingerprint recognition;identity authentication543|1298|0更新时间：2024-06-05
- 摘要：The realization to communications services of intelligent vehicle mobile terminal was discussed.Technology solutions of network architecture，signaling procedure，network handover and QoS guarantee were proposed.And the specific technology implementation scheme was proposed.关键词：LTE;Ev-Do;vehicle mobile terminal;IMS;VoLTE550|936|0更新时间：2024-06-05
- 摘要：A behavior analysis method of mobile malicious softwares and a corresponding solution on the network-side were proposed.The method combined network behaviors and virus-inner behaviors of a mobile malicious software to improve the accuracy and the timeliness.The method was a useful guidance for communication operators to block mobile malware in real time.关键词：mobile malicious software;network behavior;analysis algorithm436|848|0更新时间：2024-06-05
- 摘要：In the crowded area，China Telecom cdma2000 Ev-Do sector is configured with multi-carrier for improving the capacity.Nevertheless，the users’ experience is influenced because of the carrier’s effective coverage difference.Meanwhile，the traditional optimization methods for multi-carrier coverage such as performance index analysis and drive test are time-consuming and costly.According to the multi-carrier wireless environment typical model and combining with the DRC and call data analysis，an effective method to control the coverage of each carrier was proposed.This method can improve the optimization efficiency of China Telecom cdma2000 network by transforming the empirical method into quantitative strategy.关键词：Ev-Do;multi-carrier;coverage control373|685|0更新时间：2024-06-05
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