摘要:With the development of trusted networks,trusted routing emerges. Currently,the research focuses on the routing strategies of lightweight network. The routing algorithm has the large overhead and small applications,which is mainly based on IPv4. A trusted routing scheme was presented based on the flow label of IPv6,which was achieved by adding a flow identification module to TNC(trusted network connection)module. Drawing on previous proxy ARP,a proxy-based virtual link protocol and prototype system was designed. Experiments show that this protocol can achieve IPv6 routing based on flow label and improve the security and efficiency of information transmission.
摘要:In wireless multicast networks,it is rarely concerned that there may be certain receiving nodes which have better quality links both to the source node and to the other receiving nodes. A novel hash-neighborhoodsearch-network-coding based opportunistic relay retransmission approach was proposed. According to the packet reception status and channel quality,this novel approach dynamically selected the best suitable receiving node whose channel quality was better than the source node as a relay,then hash-neighborhood-search-network-coding strategy was used for the relay to retransmit other receiving nodes’ lost packets. Simulation results show that this novel approach can effectively reduce the number of retransmissions to improve the transmission efficiency with respect to the existing algorithms,especially when one or more of the receiving nodes are interfered and the quality of the channel between receiving nodes and source node continues to decline,this approach can achieve a high retransmission gain.
摘要:In view of the multi-user interference problem in 60 GHz pulse wireless communication system,the performance of the system based on TH-PAM multiple modulation scheme was studied. Under the IEEE 802.15.3.c channel model,relationship analysis model between system BER performance,communication distance and number of user was put forward,multi-user interference characteristics of the system with TH-PAM multiple access modulation was studied. It was compared with TH-PPM multiple access system. Simulation results show that the BER of TH-PAM multiple access system can keep below 10-5 within the scope of the communication distance is less than 30 meters,and the BER of TH-PPM multiple access system is always greater than 10-4 in range of 100 meters. As a result,TH-PAM was more suitable for 60 GHz short-range wireless communication than TH-PPM and provided technical reference for hot high capacity scenario of 5G high-frequency new hollow.
摘要:For the rate maximization problem in OFDM decode-and-forward relay system,a resource allocation algorithm based on the multi-relay forwarding was proposed. In the algorithm,the same subcarrier could be forwarded by multiple relays,and the base station could use the subcarriers that are not occupied by relays to transmit new symbols in the second phase. To reduce the computational complexity,the information transmission mode and the optimal relay set that assisting the transmission under relay mode were determined first,then the original problem was transformed into a dual problem to achieve the joint optimization solution of subcarrier-pairing and power allocation. Simulation results show that the proposed algorithm can achieve a higher system capacity.
摘要:For large-scale multiple-input multiple-output system,minimum mean square error signal detection algorithm is near-optimal but involves matrix inversion,and complexity is growing exponentially. So less-complexity signal detection algorithm using preconditioned conjugate gradient method was proposed,the algorithm reduced the condition number of matrix by pretreatment technology,thus speeding up the convergence rate of conjugate gradient signal detection algorithm. The simulation results show that the proposed algorithm can achieve the near-optimal bit error rate performance of minimum mean square error detection algorithm with a small number of iterations,and computation complexity reduces a order of magnitude. Compared with the conjugate gradient method,the proposed algorithm can quickly converge to the optimum value.
关键词:large-scale multiple-input multiple-output;conjugate gradient method;minimum mean square error
摘要:For the problem of uncertainty owing to the highly variable physical layer characteristics in cognitive radio sensor networks(CRSN),two fundamental performance metrics(bandwidth and delay)were formulated and the performance of medium access control protocol based on CSMA was analyzed. Firstly,CSMA algorithm was used to estimate potential bandwidth of secondary user under the given PU traffic model. Then,aggregated bandwidth of multiple SU simultaneous transmitting within different business channels was derived. Finally,the priority queue model M/G/C was used to analyze the delay of MAC. Performance analysis shows that dedicating a common control channel for SU enhances their aggregated bandwidth approximately five times and the packet delay reduces significantly through the possibility of concurrent transmissions on different traffic channels.
关键词:cognitive radio;sensor network;bandwidth estimation;delay estimation;primary user;secondary user
摘要:In order to guarantee the quality of service(QoS)of the cognitive radio sensor network(CRSN),the performance boundary of protocol used in CRSN is required to be accurately calculated. Therefore,a new QoS performance boundary analysis method based on stochastic network calculus (SNC)was proposed. The additive increase and multiplicative decrease(AIMD)congestion control mechanism in CRSN was used as evaluation object,and the communication delay and data backlog were used as QoS performance index. According to the sending rate distribution of the CR source sensor,the delay and backlog boundary were modeled based on stochastic network calculus with moment generating function. The experimental results show that calculated values of the model in different CRSN scenarios are within the theoretical bounds,which proves that the model has good performance.
关键词:cognitive radio sensor network;quality of service;stochastic network calculus;delay and backlog boundary
摘要:For the Sinkhole attack problem of wireless sensor network(WSN),a detection algorithm based on fusion of ant colony optimization(ACO)and P2P trust model was proposed.Firstly,ant colony optimization algorithm was used to detect the existence of a Sinkhole attack in route and generate the alarm information of sensor nodes. Then,Boolean expression evolve sign generation algorithm was used to distributed keys for group alarm nodes,and it was used to mark suspicious nodes. Finally,P2P trust model was used to compute trust value of each suspicious node,and the node with trust value was lower than the preset threshold as invasion of node. The analysis shows that the proposed algorithm need less matching search times in matching process than binary search algorithm and the rules matching based neural network(RMNN)algorithm,which indicates that it has improved the efficiency of the algorithm. Experimental results show that the proposed algorithm has higher detection accuracy on Sinkhole attack than RMNN algorithm.
关键词:wireless sensor network;Sinkhole attack;binary search algorithm;ant colony optimization;P2P trust model
摘要:Mobile agent node has become the most efficiency way of data collection in sparse wireless sensor networks,because the distance of the nodes is too far. However,the mobile agent node could not access all the nodes to gather the data in a routing travel because of energy-constrained. In order to make the energy-constrained mobile agent node obtain the minimum total route,an effective routing scheme of energy-constrained mobile agent node in sparse wireless sensor networks was presented. The mathematic model of the route of mobile agent node was built firstly,and then the whole wireless sensor network was split into different subsets according to the energy of the mobile agent node. Then the shortest routes were computed by adopting simulated annealing of traveling salesman problem. Finally,the obtained total route of sub-routes was the optimal route. The analysis results of simulation and performance show that the total route of the presented scheme is close to the ideal situation along with the increase of the number of nodes and the raise of the energy of mobile agent node. So the presented scheme is very effective in the practice and is propitious to popularize.
摘要:Traditional single satellite geolocation is divided into two separate phases:parameter estimation and target positioning,which causes non-optimal localization. To address this issue,a method of single satellite passive geolocation using spatial sparsity was presented. After continuously measuring the Doppler frequency of the target signal and using the sparse distribution of the interference on the ground,a convex problem achieving geolocation through establishing the relation between Doppler frequency and target position of the interfering signal was introduced. The method leveraged cumulative time and spatial distribution of the interference and geolocation was completed in one phase. The simulations confirm that the proposed method can get high accuracy in single satellite geolocation.
摘要:Massive multiple-input multiple-output(MIMO)refers to the idea equipping cellular base stations with a very large number of antennas,and is a communication way of severing several users. Widely-linear optimized block diagonalization type precoding techniques was proposed to alleviate the impact of IQ imbalance in the downlink massive multi-input multi-output systems. Numerical results show that significant performance can be gain compared to BD and WL-BD.
摘要:According to the “Table of Frequency Allocations of People’s Republic of China”and the relevant provisions of the“Radio Regulations”,it is shown that there are frequency overlap between the space to ground(down) link of the fourth-generation international maritime satellite(INMARSAT)mobile communication system and the next generation international mobile telecommunication(IMT)system in China. In order to guarantee the coexistence of the fourth-generation INMARSAT mobile communication system and the next generation of IMT system,the operation prerequisites or protection distances were analyzed. Based on the theoretical analysis,the simulation and survey of production level of equipment company,some suggestions on how to make the above two systems coexist were presented.
关键词:the fourth-generation international maritime satellite mobile communication system;IMT system;frequency sharing;coexistence;protection distance
摘要:Real-time is an important criterion for evaluation of the real-time video traffic. Most of the existing scheduling algorithms have a wide distribution of user time delay. Firstly,based on the analysis of the existing scheduling algorithms and system rate,an algorithm called MT-LWDF was proposed. Secondly,obtained the range of β after the theoretical analysis,the optimal value of β was got by computer simulation. Then,β was set with the optimal value,the simulation relating to average delay of the system,maximum delay of the users,rate of the system,video frame loss rate and other performance was done. And the results indicate that MT-LWDF algorithm can reduce the distribution of user delay at the same time of optimizing the rate of the system.
摘要:Computer intelligence technology had been widely used in the field of image searching. Extreme learning machine has emerged as a new technology which overcomes the problems in traditional intelligent field and it has attracted more and more researchers. The algorithm performance of ELM was analyzed firstly,extending the method to image classification field. A basic mobile visual searching(BMVS)framework was proposed which applies ELM to image searching and optimizes the performance of ELM. Finally,the experiment proves the effectiveness of the method proposed by using ELM for the mobile vision searching. Through the experiments of comparison with SVM-based methods,the efficiency of the method proposed was also confirmed.
摘要:The principle and detailed process of 16 bit image lossy compression were given. The data of 16 bit image is large and JPEG does not support the 16 bit image compression,which makes it inconvenience in 16 bit image’s storage and transmission. Based on the scheme of JPEG compression,the statistical model was expended (improving the tables of statistical model for DC coefficient coding and statistical model for AC coefficient coding respectively). This made it can deal with the data of 16 bit and realized the ideal of the compression of 16 bit static images. The quantization table used was generated based on the Luminance quantization table in JPEG. The encoder adopted was QM arithmetic encoder. An objective evaluation standard PSNR was chosen to evaluate the quality of the decompressed images.
关键词:16 bit image lossy compression;statistical model for DC coefficient coding;statistical model for AC coefficient coding;QM arithmetic encoder
摘要:With the development of information society,the information flow in the network began to grow rapidly,optical network requires not only large capacity and long distance transmission,but also the need for dynamic and flexible controls,the traditional automatic switching optical network architecture is very difficult to meet it. At the same time,storage access to massive amounts of data is a very high requirement for the scalability of the distributed storage architecture. A resource balancing strategy based on SDN for the inter-domain optical network virtualization service was proposed. Simulation results indicate that network resources can be allocated effectively,service acceptance ratio is improved,and network blocking probability is reduced.
摘要:Recently,a new technology called LTE-U proposed by 3GPP is under study. It aims to relieve the pressure in licensed spectrum. Firstly,an overview of LTE-U was presented,and then the working frequency spectrum and design principles were analyzed. The possible deployment scenarios and operation modes of LTE-U were also summarized. The difficulties in deploying LTE-U and existing solutions were discussed particularly. Finally,several possible future research directions of LTE-U were presented.
摘要:The industry has been more and more aware of the important value of network technologies to the 5G system since the vision and the concept of 5G has become clear and focused. Taking higher performance and efficiency as its objective,5G network is about to reconstruct the entire architecture and service provision system to meet the demands of 5G KPIs,scenarios and operations. A top-down design method was introduced which firstly identified the relationships between 5G requirements and technology challenge on legacy network and deduced the development direction of 5G architecture,then the 5G high-level framework of network architecture and infrastructure were raised and the architecture solution for each network function plane and the key network service named as network slicing were proposed in detail. Finally,the standardization progress in main SDOs was summarized. The solution raised can match the 5G service and operational requirements and give an active impetus to the subsequent 5G network research.
摘要:The deployment scenario,coverage strategy and site assignment of TD-LTE microcell base station(MiBS) are different from macrocell base station(MaBS). Using PTN backhaul network of traditional MaBS to carry TD-LTE MiBS will face three challenges:low network performance,poor security and low intelligence. How to build an efficient,safe and intelligent backhaul network solution for MiBS was investigated. Based on China Mobile’s current network,PON+CMNet,PTN+CMNet,PON+PTN,PTN end-to-end four kinds of small cell backhaul network solutions were proposed and furtherly tested and verified. The result shows that 4 solutions all satisfy the communication business requirements of MiBS. In particular,PON+CMNet solution is better than the others in terms of network security,intelligence and efficiency.
关键词:TD-LTE microcell base station;efficiency;security;intelligence;PON;CMNe
摘要:With the development of cloud computing,it is more convenient to implement cloud platform by using open source software,cloud platforms usually use local hard disk or shared storage to store virtual machine file. In view of the advantages and disadvantages of these two kinds of storage modes,a method supporting two kinds of storage modes in cloud platform building based on OpenStack was presented. Users specified different parameters to create virtual machine in a corresponding storage mode,so as to meet the needs of different storage business. The method solved the support of cloud platform for different storage modes,promoted the existing network system to migrate to OpenStack cloud platform and played an important role in cloud service platform.
摘要:CSFB has been adopted by many terminal manufacturers as one of the LTE voice solution. Restricted by CSFB mechanism,there exists one kind of GSM neighbor cell which is referred as shadow neighbor cell. Even without neighbor relations configured,shadow neighbor could lead UE(user equipment)to fall back successfully due to itsultra-long coverage and strong Rx level,and that would probably causes problems like dropped calls. Based on large data of road test and network of China Mobile Hangzhou Branch,the existence of shadow neighbor cell was pointed out,an optimization method of TD-LTE shadow neighbor cell was proposed,the hidden shadow neighbor cells were dug out,and they were eliminated by adjustments of antenna and frequency. Experimental results show that the method proposedis practical,effective and also worthy promotion.
关键词:CSFB;shadow neighbor cell;ultra-long coverage;same frequency
摘要:During wireless network optimization,a variety of network data would be used. However,the presence of dispersed storage,low utilization rate and inconvenience in using and other issues of existing data are incapable of meeting the future needs of large data network optimization.Referring from the big data technology widely used in internet field,network optimization center,an architecture design of network optimization big data sharing platform was proposed,dispersed data was intergrated,and a unified data sharing port was formulated,which could utilize efficiency of data usage. Moreover,the sharing platform is able to support interoperability between software of computer and applications of telephone,which provides convenience for network optimization,consequently increase efficiency and quality of network optimization.
摘要:For power big data collected during smart grid construction process,based on the demand of power system global and real-time data analysis,ideas of solving power system security and reliability,real-time status monitoring,energy global dynamic balance scheduling and other key issues were explored. The problems of big data safety and reliability,equipment life-cycle management and energy real-time balance scheduling were analyzed and discussed,system analysis precision and accuracy based on large-scale real-time multi-source detail data and global data of equipment would be improved,then application of in-memory computing,real-time streaming data processing technology,massively parallel computing technology and column stores were explored;a layered architecture of power big data analytics platform which combined with the mainstream open source big data processing technology was proposed to provide guarantees for the efficient operation of the power system.
关键词:power big data;global real-time data;in-memory computing;data stream;massively parallel
摘要:As the improvement of the enterprise’s informationalization level and the increasing management requirement of enterprise refinement,the demand of data management of enterprise is becoming greater and greater,how to improve the data quality of the enterprise is the key problem needed to be solved. Aiming at the challenges of data quality management that the power enterprise faces,some solutions for distributed data quality management were proposed. After researching the system features of data quality,some foreign and domestic cases of big data were analyzed as reference,and a solution based on Hadoop distributed processing framework was given to solve the performance bottleneck of centralized data quality system. Hadoop clustering could dissociate defect data from Oracle and the data would be stored separately on multiple servers of the clustering,which could improve the I/O performance and data analysis performance of the magnetic disk effectively.
摘要:With the development of electric power information,the accumulation of power data is more and more fast,and the issue of how to make big data to support the scientific development of the company is increasingly mentioned. In the year of 2011,Inner Mongolia Power Company started to build integrated platform data center. The company has completed the company’s business data integration work,and provided a basis for the use of data. Based on the construction of integrated production and management decision-making analysis system,the Inner Mongolia Power Company in the data warehouse application exploration and attempt was introduced from the application needs,application technology,data analysis and mining. Summary of the results and experience of construction shows that the key of application analysis is demand management and the technology is datamining.
关键词:electric power big data;data center;data warehouse
摘要:Based on the innovative development trend brought by industrial internet in America,industry 4.0 in Germany and integration of informatization and industrialization policy in China,from the perspective of power generation enterprise,the thinking of Guohua Power on the development of“three-in-one”construction framework of smart power station,and the detailed design scheme using“one control and three management”center,the“APS+field bus”digital technology application and“one body two wings three promotion”information construction as the core,were stated. Following this blueprint,program management approach was innovated,the problem that the implementation workis multiple,complex and strongly relevant was solved,initial results in six areas was achieved,the overall operation level of power plant was improved,and experience for the development of smart power industry in China was accumulated.
关键词:industry 4.0;smart;power generation;integration of informatization and industrialization
摘要:A new digital nuclear power station architecture blueprint and plan were put forward. With the concept of the full lifecycle management of nuclear power station,design data,construction data,commissioning data,real-time data and business process data for the project were integrating effectively from engineering period to operation period. Adopting advanced information technology,an intelligent or digital nuclear power station would be constructed to achieve resource sharing across platforms for structured data and unstructured data. The concept,significance,progress of digital nuclear power station were introduced,and the idea of construction of digital nuclear power plant information platform was put forward. Data center and information platform were established respectively,so as to realize the real meaning of digital nuclear power station.
关键词:digitalization;informationization;nuclear power
摘要:Under the two kinds of system operation conditions,abnormal state and normal state,indicated data on behalf of the system running status was collected by system monitoring tools such as nmon,and the obtained index data was quantitatively operated. The features of multidimensional behavior was constructed which could reflect the running state of the system. The index data has been carried on by effective feature extraction by means of the between-class and within-class distance measurement criterion,and knowledge base of behavior features was constructed which reflects the system running state. The decision tree was constructed to judge whether the system of state was secure through data features of behavior knowledge base.
关键词:knowledge base of behavior feature;between-class and within-class distance measurement criterion;decision tree