最新刊期
卷 32 ， 期 2 ， 2016
- 摘要：Network programmable technologies enforce the capacity of flexible configuration and resource composition by providing network devices with programmable interfaces. Starting with the discussion on the background in the naissance and developments of network programmable technologies，the initial programmable technologies，frameworks of control and data plane and typical software defined networking （SDN）and network function virtualization（NFV）were reviewed. The research on protocol irrelevance，implementation of flow tables， high-level programming languages and integration with NFV were elaborated. Moreover，the future works were summarized in the end.关键词：network programmability;software defined networking;network function virtualization;protocol irrelevance;programming language784|1770|0更新时间：2024-06-05
- 摘要：The shortage of traditional mobile cellular band makes the development of higher frequency paid more and more attention. The time domain measurement system based on PN sequence was used to measure propagation characteristics of the line-of-sight（LOS）and non-line-of-sight（NLOS）scenarios of conference room at 15 GHz. The channel large scale fading characteristics and the relationship between distance and path loss were analyzed，and path loss exponent and the shadow fading standard variance were calculated. In the measurement，one double ridged guide antenna with 27 dBi gain and one omni antenna were used. Through changing azimuth angles in transmitting terminal in the measurement points，the relationship between received power and different angles were analyzed.关键词：5G;15 GHz;channel measurement;large scale fading723|1218|0更新时间：2024-06-05
- 摘要：Shut down underutilized base station is a promising approach to reduce energy consumption of network during its off-peak time. The users in sleeping cell were served by neighboring cells，thus avoiding base station transmit power consumption caused by cell range expansion. Base station sleeping technique was combined with CoMP transmission to improve system performance，fully considered power consumption in the cooperative processing，and a scheme of dynamic clustering and base station sleeping to minimize power consumption was proposed. This scheme could select the best cluster to meet each user’s QoS requirement and minimize system power consumption. Simulation results show that the proposed scheme is better than traditional base station sleeping scheme in improving energy efficiency.关键词：energy efficiency;base station sleeping;coordinated multi-point;dynamical clustering724|1094|0更新时间：2024-06-05
- 摘要：According to the special scene of intra/inter chip wireless interconnection system on PCB in WCAN，an efficient networking scheme based on cellular Ad Hoc was proposed，the network model of WCAN-PCB，multiple access，wireless nodes design，routing，and flow control strategy were analyzed. Finally，the network performance comparison with the wireless Mesh scheme was also given. The simulation and computation results show that the proposed scheme could keep a lower network delay and jitter，a higher throughput of network，also maintain a relatively low packet loss rate in the high speed data transmission，primarily serves as a reference value to the future research of WCAN networking architecture and 5G technology.关键词：5G technology;chip wireless interconnection;cellular Ad Hoc;wireless chip area network;PCB619|981|0更新时间：2024-06-05
- 摘要：Performance analysis of random access network protocol in wireless local area network is a research hotspot in recent years，and the existing models have yet to describe post-backoff mechanism effectively. Therefore， the performance of the random access network under the unsaturated condition based on a two stage Markov model was analyzed. First of all，embedded Markov chain was used to describe the service process of the head-of-line （HOL）packet in each node，then the concept of virtual service time was introduced，namely regarding the p ost-backoff process after the successful transmission as a part of the HOL packet service time，then the virtual service time distribution of the HOL packet was attained. Next，the queuing process of each node was considered as a Geo/G/1 system，then the close-form result of system throughput，delay and the range of the stable region under the unsaturated condition was achieved. The simulation results have verified the accuracy of our model. The model will shed light on the future research on distributed coordination function（DCF）protocol in wireless local area network.关键词：random access network;post-backoff;performance analysis;Markov chain521|1102|0更新时间：2024-06-05
- 摘要：Multiple-input multiple-output non-contiguous orthogonal frequency division multiplexing（MIMO NC-OFDM）system is a commonly used system in cognitive radio. One of the key technical that affects the MIMO NC-OFDM performance is channel estimation in the condition of non-continuous carrier caused by licensed users’ occupation. Sparsity adaptive matching pursuit（SAMP）algorithm was proposed as a new method to estimate sparse channel in MIMO NC-OFDM system. Compared with other state-of-the-art greedy algorithms，the most innovative feature of the SAMP is that it is capable to adjust the step length adaptively to approach the original signal and reconstruct the sparse signal without prior information of the sparsity. Simulation result shows that，the new channel estimation method outperforms many existing iterative algorithms in reconstruction performance and can be implemented easily in practical application.关键词：multiple-input multiple-output non-contiguous orthogonal frequency division multiplexing;cognitive radio;compressed sensing;channel estimation;sparsity adaptive matching pursuit1134|882|0更新时间：2024-06-05
- 摘要：The approximation algorithm of single virtual network mapping solution aimed to minimize the mapping cost based on convex quadratic programming relaxation was designed. Then aiming for dynamic arrival construction request of the single virtual network，the mapping scheme was achieved based on physical network resource pricing strategy by shadow price，applying above-mentioned approximation algorithm. And then completed the competitive algorithm design based on virtual network admission control strategy by mapping cost constraint and provided the competitive analysis of this algorithm. Experiment results show that the proposed algorithm increases the effective utilization of physical network resources，hence it can improve the virtual network construction request acceptance ratio and the long-term profit of physical network service provider.关键词：virtual network mapping;mapping cost;convex quadratic programming relaxation;admission control;competitive algorithm299|618|0更新时间：2024-06-05
- 摘要：Traffic flow modeling plays an important role in routing，MAC algorithm and protocol designs in vehicular Ad Hoc networks （VANET）. An accurate traffic flow model is crucial to traffic management of an intelligent transportation system （ITS）and information safety in a VANET. Based on Shanghai’s traffic flow data，the performance of the two different models was compared using auto regressive（AR）model and back-propagation（BP） network model，and the corresponding prediction result was given. Research finds that both of the two models can efficiently predict the traffic data，but they have different prediction accuracy for the data of different periods. The research result will provide support for future research on ITS and VANET.关键词：VANET;ITS;AR model;BP network model;traffic flow predicting497|1225|0更新时间：2024-06-05
- 摘要：BP neural network provides a robust and effective learning method for approximating real values. It is fit for intersection traffic flow prediction. In order to resolve its slow convergence speed and easily falling into local minimum problem，an ensemble prediction model was proposed. This model integrated multiple BP neural networks which had different initial weights and training set and used weighted average as combination method. It had used an improved MapReduce method to implement every BP neural network of the ensemble prediction model. This ensemble prediction model took traffic shunt flow prediction at intersection as an example. At last，it was compared with simple single implementation BP model and MapReduce implementation BP model respectively. Finally，results prove that ensemble prediction model has a higher accuracy rate and real-time performance in traffic shunt flow prediction at intersection.关键词：BP neural network;ensemble prediction;MapReduce;weighted average;traffic shunt flow prediction at intersection428|1856|0更新时间：2024-06-05
- 摘要：A data offloading strategy for optimizing itinerary planning of MA（mobile agent）was proposed. When MA visits source nodes based on data offloading strategy，it decides whether to transfer data package via optimized offloading itinerary and MA（mobile agent）visits data source nodes via conventional itinerary. Based on considerable simulations with the representative MA itinerary planning，i.e. itinerary energy minimum for first-source-selection （IEMF），it verifies that the problem of excessive energy consumption from source nodes can be efficiently solved and the lifetime of source nodes is prolonged.关键词：data offloading;mobile agent;itinerary planning;wireless sensor network308|685|0更新时间：2024-06-05
- 摘要：WINNER and COST2100 channel models are geometry based statistical models，they are the most important channel models for MIMO（multi-input multi-output）system simulations in the fourth generation（4G）radio systems. Due to different physical mechanism advantages for WINNER and COST2100 models，there is almost no work available for the comparative studies between the two channel models and effectiveness and agreement in a specific scenario. The channel simulation and measurement studies for the two channel models in indoor environment was focused on. In the line-of-sight（LOS）and non-line-of-sight（NLOS）cases，the power-delay-profile （PDP），Ricean factor，channel capacity，rms delay and rms angular spread were simulated using the two channel models and measurement data. The comparative studies between the simulation and measurement results are performed to test the effectiveness and agreement of the two models in a practical application environment.关键词：WINNER channel model;COST2100 channel model;power delay profile;Ricean factor;channel capacity;delay spread;angle spread636|2584|0更新时间：2024-06-05
- 摘要：Distributed computing for large-scale graph data need to partition the graph firstly. The current methods of large-scale graph partitioning is to reduce the edge cut in order to lessen communication overhead by using vertex transfer strategies，but easily to fall into local optimum. Simulated annealing has a great probability to avoid the trap of local optimum and prevent vertices from invalid transfer which was introduced to transfer vertices. This method decreased communication overhead greatly. Comparative experiments show that the proposed algorithm has made a great improvement in reducing edge cut rates in large scale graph partition field. PageRank algorithm was also used to verify the effectiveness and feasibility of this method.关键词：graph partition;Giraph;simulated annealing;large-scale graph;BSP587|1005|0更新时间：2024-06-05
- 摘要：With the popularity of mobile internet technology，people are not satisfied with the service that provides a single function and hope to gain the personalized or composition service according to their needs. A muti-strategy discrete differential evolution（MDDE）algorithm applied in Web service composition was put forward. The algorithm， which adopts a random selection framework and multi-mutation strategies with different properties，was the balance of search ability and convergence speed. The results indicate that the proposed algorithm is better than traditional differential evolution algorithm in solving Web service combination optimization problems in terms of the solution quality and stability.关键词：Web service composition;differential evolution;multi-strategy mutation341|720|0更新时间：2024-06-05
- 摘要：In order to mining SMS（short message service）seed customers from massive text messages，control the spread of the seed messages path and improve the efficiency of its spread，a SMS seed customers mining model and algorithm was proposed，which was based on content analysis. First of all，by analyzing the interest，randomness and one-way characteristics of customer forwarding messages，the tree model of customer forwarding messages were constructed. Secondly，the optimal seed customers mining model was generated by definition and application of comprehensive evaluation function，and SMS seed customers mining was realized based on the concept of close group. Finally，by analyzing the actual data from telecom operators，the effectivity of the model and algorithm was verified.关键词：SMS seed customer;content analysis;mining model;mining algorithm;close group345|697|0更新时间：2024-06-05
research and development
- 摘要：As one of the most efficient ways to alleviate the problem of spectrum scarcity，dynamic spectrum sharing has drawn worldwide attention. Firstly，the concept of dynamic spectrum sharing was briefly introduced. Next，from the aspects of rulemaking，standardization and application，the international development of dynamic spectrum sharing was fully investigated. Finally，based on the current situation of radio management，the impact and challenges on frequency management，radio station management and radio monitoring were analyzed.关键词：dynamic spectrum sharing;cognitive radio;white space;efficient utilization481|2833|0更新时间：2024-06-05
- 摘要：Currently，there are still some problems with IoT，specifically in：one is that the IoT gives priority to vertical service system；another is the lack of cross-system resource sharing.To solve the above problems，a scalable intelligence service architecture of IoT in which a unified service data model was proposed and a message middleware were built to overcome the multi-source heterogeneous problems in the data structure，data platforms and operating systems. In addition，a usage authorization mechanism was proposed to support security and privacy in the IoT environment， contributing to a scalable，secure and reliable intelligence open service platform for IoT.Finally，a prototype system was designed and concrete system was given to verify the feasibility and superiority of the proposed architecture.关键词：IoT;service platform;data model;middleware1035|915|0更新时间：2024-06-05
- 摘要：Hybrid cloud provides a flexible approach to the application of local resources to the public cloud. A resource scheduling scheme with the minimum cost of external cloud resource constrained by SLA was presented. The key SLA measure of the outer part of the cloud was considered as the user’s satisfaction and the lowest cost. Then，the SLA component was quantized to dynamically adjust the internal cloud resource to be unable to service and need to dispatch resources. Experimental results show that the scheme can achieve the maximum satisfaction of cost and real-time performance.关键词：cloud computing;resource management;efficient scheduling;service level agreement538|883|0更新时间：2024-06-05
- 摘要：The big data platform for gaming service is based on Hadoop open source technology. With the demand growth of the service operation staff，there are more and more jobs which depend on each other running on the big data platform. A new working flow engine was developed on Zeus to manage and schedule jobs efficiently. In order to shorten the start time，Zeus task starting process was optimized and multi-threaded start task was achieved. Zeus was also improved to support the Oracle stored procedure. Pipeline technology was used to seamless and efficient sharing and transmission of heterogeneous data sources.关键词：big data job;work flow;open source364|921|0更新时间：2024-06-05
- 摘要：With the continuous promoting of“Broadband-China”evolution，“Faster internet with cheaper tariff”in broadband field has become the important support of“internet+”.The optical access-sandwich solution was proposed based on the gradual evolution from 2G to 3G，which means reusing traditional incoming-line on the live network，distributed by replacing traditional GYTA fiber with butterfly-flexible optical cable and providing convergent DP in FTTH and FTTB. The asset-light and high-bandwidth on fixed access network can be achieved effectively with the large-scale deployment on the solution. In the environment of next generation internet，the advantage on optical access-sandwich，including advanced-technology and effective-cost，was analyzed. Meanwhile，the key point，which is reflected in the modernized telecom infrastructure in internet+，was summarized accordingly. The proposal，which included acceleration on optical-internet modernization and the asset-light & high-bandwidth on network，was put forward.关键词：Internet+;next generation internet access;optical-internet modernization;asset-light412|870|0更新时间：2024-06-05
- 摘要：The different localization and the different application scenarios between IOE and LAMP architecture were introduced. IT current situation and the driving force of removing IOE in telecom enterprise were analyzed. The differences of the business model，service characteristics and IT localization between the traditional telecom enterprises and the internet companies were studied. The overall implementation strategy of removing IOE and the suitable business scenario were proposed，and the effect of removing IOE from the billing system was expounded.关键词：internet;LAMP;IOE358|1131|0更新时间：2024-06-05
- 摘要：Focusing on the CSFB 4G UE couldn’t access no-CSFB 4G network automatically，some tests and analysis had been done and located the root cause of the problem by 3GPP specification. Some solutions about UE and 3GPP specification were presented that maked CSFB 4G UE access no-CSFB 4G network automatically and stay in a legalized network，giving users good experience.关键词：4G;circuit switched fallback;access automatically;legal network;solution301|895|0更新时间：2024-06-05
Overview
- 摘要：In order to solve the problem of low transmission efficiency and security of the grid，ensure the normal operation of power network，reduce network burden and improve the security of system access，a secure communication and private key location technology of wireless sensor based on region partition was designed by using the technology of time synchronization verification. The power transmission network in the vast amount of sensor partition effectively improved the efficiency of power grid data transmission. The risk of leakage of the coordinate mapping table to the grid data information was prevented by the leakage of the private key location technology. Through the private key and the time stamp authentication technology，the security level of the system communication was effectively increased.关键词：private key and timestamp cross certification;high strength encryption algorithm suite;leak proof private key302|625|0更新时间：2024-06-05
- 摘要：There exist many security vulnerabilities in device’s identity verification and the information transmition through RFID system，the computations and procedures in the classical RFID authentication protocols are so complex that will impose processing burdens on the data base or readers，leading to the problem of low effective information rate. To solve the problem，an improvement of ARAP protocol which called DARAP was proposed to realize authentication in RFID system for smart park. The new protocol could effectively resist attacks of re-transmission，tracking，deception，cloning and de-synchronizationand，and it had high security and practicability.关键词：RFID;smart park;lightweight;DARAP275|720|0更新时间：2024-06-05
- 摘要：Network authentication technology is the key to the application of internet plus security. The digital signature which depends on the certificate authority （CA）and PKI based on public key system is the main method for identity and message authentication. However，over the years，there are still many problems for the development of CA. The digital signature is not mutual trust and mutual recognition over the application granted by different CA. Moreover，it costs a lot to construct and maintain CA. In order to solve the above problems，one of ways for the improvement is to shorten the length of public key under the condition of not reducing the degree of security. In this way，the public key can be widely recognized under the regulations instead of the third party certification. The application of this public key technology will be an effective way to remove the existing problems of the CA.关键词：digital signature;authentication center;visual public key439|871|0更新时间：2024-06-05
- 摘要：The wireless virtual private network structure suitable for the north and south call center of SGCC was explored. In the structure，the wireless applications and communication of the north and south call center of SGCC were considered. The existing access security risks and the cannot-control defects of wireless virtual private network were analyzed，and the solutions for the center were given. Through the research on wireless virtual private network security from the four aspects as the terminal，network，boundary and application，reference for the design and construction of the center wireless virtual private network was provided.关键词：wireless virtual private network;service bearer;network structure;safety protection474|896|0更新时间：2024-06-05
- 摘要：Power line can provide electrical energy to the electric equipment，and it can also be used as a communications system for transmitting information. The reliable and efficient information transmission is the basic requirement of any kind of communication network. Based on the research of dynamic load impedance characteristic effects，attenuation characteristics of multipath effect and impulse noise interference characteristics，the feasibility of several typical inhibition technologies were analyzed，from perspective of the physical layer signal processing and the data link layer data transmission，which provided valuable reference for exploring effective technologies of pulse interference suppression in the power line communication.关键词：power line communication;impulse interference;OFDM;IDMA;fractional lower order statistics signal573|2923|0更新时间：2024-06-05
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