As an international language, English plays an extremely important role, and it has become the lingua franca of the world. For a long time, inefficiency exists in teaching or learning. Under the learning environment s...As an international language, English plays an extremely important role, and it has become the lingua franca of the world. For a long time, inefficiency exists in teaching or learning. Under the learning environment surrounded by native speakers, English, as a symbolic system, appears dull, or even because there is no information given appropriate experience and it becomes abstract. Many students are reluctant to learn after learning for a time, because it is difficult for reality, and it is not easy to consolidate, that 45 minutes of English learning environment also appears to be a little frustrated, as many students who have been admitted to the University said during the learning process of the entire university, they spent seventy percent of their energy to foreign language learning rather than their own major. This not only illustrates the importance of English teaching but also shows its difficult nature, the main reason is our bad English language teaching environment, there is a lack of communication in English language environment, however, the network information and the development of modern multimedia technology has greatly improve the English teaching environment. How to use the Internet information and multimedia technologies to create English learning environment, to optimize English teaching methods and to improve the quality of English teaching.展开更多
Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and...Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and improving users' experience. To analyse the requests' patterns and fully utilize the universal cached contents, a novel intelligent resources management system is proposed, which enables effi cient cache resource allocation in real time, based on changing user demand patterns. The system is composed of two parts. The fi rst part is a fi ne-grain traffi c estimation algorithm called Temporal Poisson traffi c prediction(TP2) that aims at analysing the traffi c pattern(or aggregated user requests' demands) for different contents. The second part is a collaborative cache placement algorithm that is based on traffic estimated by TP2. The experimental results show that TP2 has better performance than other comparable traffi c prediction algorithms and the proposed intelligent system can increase the utilization of cache resources and improve the network capacity.展开更多
Referring to the questionnaire survey and literature materials, this paper describes the current situation of college students' insufficient autonomous English learning ability and thefactors that influence this abil...Referring to the questionnaire survey and literature materials, this paper describes the current situation of college students' insufficient autonomous English learning ability and thefactors that influence this ability; it also suggests feasible suggestions under the network environment. Students (N= 178) from different grades, majors, universities and areas responded to a questionnaire survey, and the collected data were analyzed. The results indicate that complex external environment and insufficient internal subject cognition influence college students' autonomous English learning ability. Finally, this paper suggests that a good network environment is necessary for autonomous learners to enhance insufficient autonomous English learning ability and interaction, continuous thinking and cultural introduction are also indispensable to develop this ability.展开更多
How to make a good job of foreign language teaching and improve the quality of teaching is a topic which the general teaching workers are facing, in this paper, the author express ideas from many aspects, multi-angle,...How to make a good job of foreign language teaching and improve the quality of teaching is a topic which the general teaching workers are facing, in this paper, the author express ideas from many aspects, multi-angle, multi-level, this brings a valuable theory reference on methods of English teaching which is under network environment. As for the problems of how to solve the bottle neck of English teaching, how to train the talent who are more adaptive to the world economy globalization, how to get rid of the traditional teaching method in teaching and how to improve the teaching level more efficiently, this paper gave some good methods and suggestions.展开更多
Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information technologies together in the future reform of the so...Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information technologies together in the future reform of the social communication model. Under this background, the principle of digital communication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully. this paper can play a help in the future subsequent study.展开更多
Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information teclmologies together in the future reform of the so...Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information teclmologies together in the future reform of the social communication model. Under this background, the principle of digital co,nmunication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully, this paper can play a help in the future subsequent study.展开更多
Based on a survey of university teachers and students in Nanjing area of 2007,this article analyzes domestic users' awareness towards Open Access(OA),and the changes by comparing the corresponding data of 2006.The...Based on a survey of university teachers and students in Nanjing area of 2007,this article analyzes domestic users' awareness towards Open Access(OA),and the changes by comparing the corresponding data of 2006.The survey shows that the research evaluation system,the quality of literature and the payment for OA publications are the important factors for university users to choose OA or not.The authors finally suggest that the current research evaluation system should be reformed to accommodate OA journals.Meanwhile,great efforts should be devoted to improve the quality of OA literatures,and the governments and research institutions should provide stronger support than before.展开更多
In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and reso...In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and resource allocation while establishing a realistic scenario of three-tier heterogeneous network architecture. The scheme consists of two stages: in stage I, a two-level sub-channel allocation algorithm and a power control method based on the logarithmic function are applied to allocate resource for Macrocell and Picocells, guaranteeing the minimum system capacity by considering the power limitation and interference coordination; in stage II, an interference management approach based on K-means clustering is introduced to divide Femtocells into different clusters. Then, a prior sub-channel allocation algorithm is employed for Femtocells in diverse clusters to mitigate the interference and promote system performance. Simulation results show that the proposed scheme contributes to the enhancement of system throughput and spectrum efficiency while ensuring the system energy efficiency.展开更多
Physical-layer network coding(PNC) promises substantial theoretical gain to achieve the maximum system throughput in cooperative relay transmission. However, with the increasing global warming, how to reduce power con...Physical-layer network coding(PNC) promises substantial theoretical gain to achieve the maximum system throughput in cooperative relay transmission. However, with the increasing global warming, how to reduce power consumption while satisfy system throughput requirement is becoming a vital issue. In this paper, we investigate energy-efficiency resource allocation(RA) based on PNC with amplify-and-forward(AF) protocol in orthogonal frequency division multiple(OFDM) bidirectional transmission. To minimize the overall transmit power consumption with required system throughput requirement, we consider joint subcarriers and power allocation and formulate the objective task into a constrained optimization problem where the best relay node is selected to minimize total transmit power. The closed form optimization power allocation solutions are acquired by analytical derivation. Based on derivation, we propose a novel optimal energy-efficient power allocation(OE-PA). Numerical results are given to evaluate the performance of the derived scheme as compared to other schemes and show that our scheme has signifi cant improvement to energy saving.展开更多
In the upcoming 5 G heterogeneous networks, leveraging multiple radio access technologies(RATs) shows to be a crucial issue in achieving RAT multiplexing gain to meet the explosive traffic demand. For always best conn...In the upcoming 5 G heterogeneous networks, leveraging multiple radio access technologies(RATs) shows to be a crucial issue in achieving RAT multiplexing gain to meet the explosive traffic demand. For always best connection(ABC), users tend to activate parallel transmission across all available RATs. However from a system-wide perspective, this might not be optimal given the context of network load, interference and diverse service requirements. To intelligently determine how to use these multi-RAT access resources concurrently, this paper proposes a joint multi-RAT user association and resource allocation strategy with triple decision and integrated context awareness of users and networks. A dynamic game based ant colony algorithm(GACA) is designed to simultaneously maximize the system utility and the fairness of resource allocation. Simulation results show that it's more reasonable to make multi-RAT association decision from a system-wide viewpoint than from an individual one. Compared to max-SNR based and ABC based strategies, the proposed method alleviates network congestion and optimizes resource allocation. It obtains 39%~70% performance improvement.展开更多
The pursuit of high data rate and assurance of quality of experience(QoE) for end users represent the main goals of future wireless communication systems.By introducing MOS(Mean Opinion Score) based assessment models ...The pursuit of high data rate and assurance of quality of experience(QoE) for end users represent the main goals of future wireless communication systems.By introducing MOS(Mean Opinion Score) based assessment models for different types of applications,this paper proposed novel QoE-oriented radio resource allocation(RRA) algorithms for multiuser-multiservice femtocell networks.An optimal QoE-oriented RRA strategy is first analyzed using time-sharing method which is applicable to best effort applications.RRA algorithms based on the cross-layer architecture are then proposed for all types of applications by considering parameters extracted from different layers of networking protocols.In the proposed algorithms,a priority mechanism is employed to ensure fairness.Simulation results show that the proposed algorithms can significantly improve the overall perceived quality from the users' perspective in comparison with traditional Quality of Service(QoS)oriented algorithms.展开更多
The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challengi...The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challenging and this is the focus of this paper. In this paper, the eavesdropper is hidden from the macro base stations. To relax the unpractical assumption on the channel state information on eavesdropper, a localization based algorithm is first given. Then a joint resource allocation algorithm is proposed in our work, which simultaneously considers physical layer security, cross-tier interference and joint optimization of power and subcarriers under fairness requirements. It is revealed in our work that the considered optimization problem can be efficiently solved relying on convex optimization theory and the Lagrangian dual decomposition method is exploited to solve the considered problem effectively. Moreover, in each iteration the closed-form optimal resource allocation solutions can be obtained based on the Karush-Kuhn-Tucker(KKT) conditions. Finally, the simulation results are given to show the performance advantages of the proposed algorithm.展开更多
In spectrum aggregation(SA), two or more component carriers(CCs) of different bandwidths in different bands can be aggregated to support wider transmission bandwidth. The current resource scheduling schemes for spectr...In spectrum aggregation(SA), two or more component carriers(CCs) of different bandwidths in different bands can be aggregated to support wider transmission bandwidth. The current resource scheduling schemes for spectrum aggregation are not optimal or suitable for CR based heterogeneous networks(Het Nets). Consequently, the authors propose a novel resource scheduling scheme for spectrum aggregation in CR based Het Nets, termed as cognitive radio based resource scheduling(CR-RS) scheme. CR-RS has a three-level structure. Under a dynamic traffic model, an equivalent throughput of the CCs based on the knowledge of primary users(PUs) is given. On this basis, the CR users data transmission time of each CC is equal in CR-RS. The simulation results show that CR-RS has the better performance than the current resource scheduling schemes in the CR based Het Nets. Meanwhile, CR-RS is also effective in other spectrum aggregation systems which are not CR based HetNets.展开更多
In this paper,a distributed chunkbased optimization algorithm is proposed for the resource allocation in broadband ultra-dense small cell networks.Based on the proposed algorithm,the power and subcarrier allocation pr...In this paper,a distributed chunkbased optimization algorithm is proposed for the resource allocation in broadband ultra-dense small cell networks.Based on the proposed algorithm,the power and subcarrier allocation problems are jointly optimized.In order to make the resource allocation suitable for large scale networks,the optimization problem is decomposed first based on an effective decomposition algorithm named optimal condition decomposition(OCD) algorithm.Furthermore,aiming at reducing implementation complexity,the subcarriers are divided into chunks and are allocated chunk by chunk.The simulation results show that the proposed algorithm achieves more superior performance than uniform power allocation scheme and Lagrange relaxation method,and then the proposed algorithm can strike a balance between the complexity and performance of the multi-carrier Ultra-Dense Networks.展开更多
Cache-enabled small cell networks have been regarded as a promising approach for network operators to cope with the explosive data traffic growth in future 5 G networks. However, the user association and resource allo...Cache-enabled small cell networks have been regarded as a promising approach for network operators to cope with the explosive data traffic growth in future 5 G networks. However, the user association and resource allocation mechanism has not been thoroughly studied under given content placement situation. In this paper, we formulate the joint optimization problem of user association and resource allocation as a mixed integer nonlinear programming(MINLP) problem aiming at deriving a balance between the total utility of data rates and the total data rates retrieved from caches. To solve this problem, we propose a distributed relaxing-rounding method. Simulation results demonstrate that the distributed relaxing-rounding method outperforms traditional max-SINR method and range-expansion method in terms of both total utility of data rates and total data rates retrieved from caches in practical scenarios. In addition, effects of storage and backhaul capacities on the performance are also studied.展开更多
The approach of traffic abnormality detection of network resource allocation attack did not have reliable signatures to depict abnormality and identify them. However, it is crucial for us to detect attacks accurately....The approach of traffic abnormality detection of network resource allocation attack did not have reliable signatures to depict abnormality and identify them. However, it is crucial for us to detect attacks accurately. The technique that we adopted is inspired by long range dependence ideas. We use the number of packet arrivals of a flow in fixed-length time intervals as the signal and attempt to extend traffic invariant “self-similarity”. We validate the effectiveness of the approach with simulation and trace analysis.展开更多
In the Internet of things, it is of critical importance to fully utilize the potential capacity of the network with efficient medium access control (MAC) mechanisms. In this paper, we study the convergence property ...In the Internet of things, it is of critical importance to fully utilize the potential capacity of the network with efficient medium access control (MAC) mechanisms. In this paper, we study the convergence property of the fixed point formulation of distributed coordination function (DCF), which is widely used for medium access control in wireless networks. We first Kind that the fixed point could be repelling, which means that it is impossible for an MAC system to converge at its fixed point. Next, we show the existence of periodic points to prove that the fixed point function will oscillate between two periodic points when the fixed point is repelling. We also find that the average of the two periodic points is a close approximation of the fixed point. Based on the findings, we propose an algorithm to compute the fixed point efficiently. Simulation results verify the accuracy and efficiency of our algorithm compared with the previous fixed point computing method.展开更多
Reorganization of network information resources for scientific and technical (scitech for abbreviation) documents and development of information infrastructure have brought a great change in China's scitech documen...Reorganization of network information resources for scientific and technical (scitech for abbreviation) documents and development of information infrastructure have brought a great change in China's scitech documentation information sharing. It integrated not only information resources, but also systems, technologies and funds. High quality services and effective resources sharing are the main goals of the platform construction. The paper describes briefly the principles and aims of the integration of the scitech information resources and networks. The services of the sharing platforms have been also introduced.展开更多
In Chinese traditional culture, ceramic culture is a very special cultural system, With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development ...In Chinese traditional culture, ceramic culture is a very special cultural system, With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development and utilization is especially important. The idea of Web3.0 make important ceramic culture network native digital resources "reasonable configuration", t o be more embody the value of academic research. In this paper, we'll discuss the conformity utilization of ceramic culture native digital resources based on the concept of WEB3.0.展开更多
In Chinese traditional culture, ceramic culture is a very special cultural system With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development a...In Chinese traditional culture, ceramic culture is a very special cultural system With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development and utilization is especially important. The idea of Web3.0 make important ceramic culture network native digital resources "reasonable configuration", t o be more embody the value of academic research. In this paper, we'll discuss the conformity utilization of ceramic culture native digital resources based on the concept of WEB3.0.展开更多
文摘As an international language, English plays an extremely important role, and it has become the lingua franca of the world. For a long time, inefficiency exists in teaching or learning. Under the learning environment surrounded by native speakers, English, as a symbolic system, appears dull, or even because there is no information given appropriate experience and it becomes abstract. Many students are reluctant to learn after learning for a time, because it is difficult for reality, and it is not easy to consolidate, that 45 minutes of English learning environment also appears to be a little frustrated, as many students who have been admitted to the University said during the learning process of the entire university, they spent seventy percent of their energy to foreign language learning rather than their own major. This not only illustrates the importance of English teaching but also shows its difficult nature, the main reason is our bad English language teaching environment, there is a lack of communication in English language environment, however, the network information and the development of modern multimedia technology has greatly improve the English teaching environment. How to use the Internet information and multimedia technologies to create English learning environment, to optimize English teaching methods and to improve the quality of English teaching.
基金supported by the National High Technology Research and Development Program(863)of China(No.2015AA016101)the National Natural Science Fund(No.61300184)Beijing Nova Program(No.Z151100000315078)
文摘Information centric networking(ICN) is a new network architecture that is centred on accessing content. It aims to solve some of the problems associated with IP networks, increasing content distribution capability and improving users' experience. To analyse the requests' patterns and fully utilize the universal cached contents, a novel intelligent resources management system is proposed, which enables effi cient cache resource allocation in real time, based on changing user demand patterns. The system is composed of two parts. The fi rst part is a fi ne-grain traffi c estimation algorithm called Temporal Poisson traffi c prediction(TP2) that aims at analysing the traffi c pattern(or aggregated user requests' demands) for different contents. The second part is a collaborative cache placement algorithm that is based on traffic estimated by TP2. The experimental results show that TP2 has better performance than other comparable traffi c prediction algorithms and the proposed intelligent system can increase the utilization of cache resources and improve the network capacity.
文摘Referring to the questionnaire survey and literature materials, this paper describes the current situation of college students' insufficient autonomous English learning ability and thefactors that influence this ability; it also suggests feasible suggestions under the network environment. Students (N= 178) from different grades, majors, universities and areas responded to a questionnaire survey, and the collected data were analyzed. The results indicate that complex external environment and insufficient internal subject cognition influence college students' autonomous English learning ability. Finally, this paper suggests that a good network environment is necessary for autonomous learners to enhance insufficient autonomous English learning ability and interaction, continuous thinking and cultural introduction are also indispensable to develop this ability.
文摘How to make a good job of foreign language teaching and improve the quality of teaching is a topic which the general teaching workers are facing, in this paper, the author express ideas from many aspects, multi-angle, multi-level, this brings a valuable theory reference on methods of English teaching which is under network environment. As for the problems of how to solve the bottle neck of English teaching, how to train the talent who are more adaptive to the world economy globalization, how to get rid of the traditional teaching method in teaching and how to improve the teaching level more efficiently, this paper gave some good methods and suggestions.
文摘Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information technologies together in the future reform of the social communication model. Under this background, the principle of digital communication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully. this paper can play a help in the future subsequent study.
文摘Along with the mature development of the domestic computer technology and communication technology, it is an inevitable trend to integrate the two major information teclmologies together in the future reform of the social communication model. Under this background, the principle of digital co,nmunication is introduced first in this paper, and accordingly the role of the communication network resources sharing is analyzed, and finally the sharing management of digital communication network resources is proposed. Hopefully, this paper can play a help in the future subsequent study.
文摘Based on a survey of university teachers and students in Nanjing area of 2007,this article analyzes domestic users' awareness towards Open Access(OA),and the changes by comparing the corresponding data of 2006.The survey shows that the research evaluation system,the quality of literature and the payment for OA publications are the important factors for university users to choose OA or not.The authors finally suggest that the current research evaluation system should be reformed to accommodate OA journals.Meanwhile,great efforts should be devoted to improve the quality of OA literatures,and the governments and research institutions should provide stronger support than before.
基金partially supported by the Major Project of National Science and Technology of China under Grants No. 2016ZX03002010003 and No. 2015ZX03001033-002
文摘In 5 G Ultra-dense Network(UDN), resource allocation is an efficient method to manage inter-small-cell interference. In this paper, a two-stage resource allocation scheme is proposed to supervise interference and resource allocation while establishing a realistic scenario of three-tier heterogeneous network architecture. The scheme consists of two stages: in stage I, a two-level sub-channel allocation algorithm and a power control method based on the logarithmic function are applied to allocate resource for Macrocell and Picocells, guaranteeing the minimum system capacity by considering the power limitation and interference coordination; in stage II, an interference management approach based on K-means clustering is introduced to divide Femtocells into different clusters. Then, a prior sub-channel allocation algorithm is employed for Femtocells in diverse clusters to mitigate the interference and promote system performance. Simulation results show that the proposed scheme contributes to the enhancement of system throughput and spectrum efficiency while ensuring the system energy efficiency.
基金supported by the Science Instrument Special Funds of the National Natural Science Foundation of China under Grant No.61027003the National High Technology Research and Development Program of China under Grant No.2012AA01A50604
文摘Physical-layer network coding(PNC) promises substantial theoretical gain to achieve the maximum system throughput in cooperative relay transmission. However, with the increasing global warming, how to reduce power consumption while satisfy system throughput requirement is becoming a vital issue. In this paper, we investigate energy-efficiency resource allocation(RA) based on PNC with amplify-and-forward(AF) protocol in orthogonal frequency division multiple(OFDM) bidirectional transmission. To minimize the overall transmit power consumption with required system throughput requirement, we consider joint subcarriers and power allocation and formulate the objective task into a constrained optimization problem where the best relay node is selected to minimize total transmit power. The closed form optimization power allocation solutions are acquired by analytical derivation. Based on derivation, we propose a novel optimal energy-efficient power allocation(OE-PA). Numerical results are given to evaluate the performance of the derived scheme as compared to other schemes and show that our scheme has signifi cant improvement to energy saving.
基金supported by the National Natural Science Fund of China(Grant NO.61771065,Grant NO.61571054 and Grant NO.61631005)Beijing Nova Program(NO.Z151100000315077)
文摘In the upcoming 5 G heterogeneous networks, leveraging multiple radio access technologies(RATs) shows to be a crucial issue in achieving RAT multiplexing gain to meet the explosive traffic demand. For always best connection(ABC), users tend to activate parallel transmission across all available RATs. However from a system-wide perspective, this might not be optimal given the context of network load, interference and diverse service requirements. To intelligently determine how to use these multi-RAT access resources concurrently, this paper proposes a joint multi-RAT user association and resource allocation strategy with triple decision and integrated context awareness of users and networks. A dynamic game based ant colony algorithm(GACA) is designed to simultaneously maximize the system utility and the fairness of resource allocation. Simulation results show that it's more reasonable to make multi-RAT association decision from a system-wide viewpoint than from an individual one. Compared to max-SNR based and ABC based strategies, the proposed method alleviates network congestion and optimizes resource allocation. It obtains 39%~70% performance improvement.
基金supported in part by the National Nature Science Foundation of China under Grant 61372117the 863 project under grant No.2014AA01A701the National Key Technology Support Program under grant No.2012BAH41F03
文摘The pursuit of high data rate and assurance of quality of experience(QoE) for end users represent the main goals of future wireless communication systems.By introducing MOS(Mean Opinion Score) based assessment models for different types of applications,this paper proposed novel QoE-oriented radio resource allocation(RRA) algorithms for multiuser-multiservice femtocell networks.An optimal QoE-oriented RRA strategy is first analyzed using time-sharing method which is applicable to best effort applications.RRA algorithms based on the cross-layer architecture are then proposed for all types of applications by considering parameters extracted from different layers of networking protocols.In the proposed algorithms,a priority mechanism is employed to ensure fairness.Simulation results show that the proposed algorithms can significantly improve the overall perceived quality from the users' perspective in comparison with traditional Quality of Service(QoS)oriented algorithms.
基金supported by the National Natural Science Foundation of China under Grant No.61371075the 863 project SS2015AA011306
文摘The tremendous performance gain of heterogeneous networks(Het Nets) is at the cost of complicated resource allocation. Considering information security, the resource allocation for Het Nets becomes much more challenging and this is the focus of this paper. In this paper, the eavesdropper is hidden from the macro base stations. To relax the unpractical assumption on the channel state information on eavesdropper, a localization based algorithm is first given. Then a joint resource allocation algorithm is proposed in our work, which simultaneously considers physical layer security, cross-tier interference and joint optimization of power and subcarriers under fairness requirements. It is revealed in our work that the considered optimization problem can be efficiently solved relying on convex optimization theory and the Lagrangian dual decomposition method is exploited to solve the considered problem effectively. Moreover, in each iteration the closed-form optimal resource allocation solutions can be obtained based on the Karush-Kuhn-Tucker(KKT) conditions. Finally, the simulation results are given to show the performance advantages of the proposed algorithm.
基金supported by Major National Science and Technology Project(2014ZX03004003-005)Municipal Exceptional Academic Leaders Foundation (2014RFXXJ002)China Postdoctoral Science Foundation (2014M561347)
文摘In spectrum aggregation(SA), two or more component carriers(CCs) of different bandwidths in different bands can be aggregated to support wider transmission bandwidth. The current resource scheduling schemes for spectrum aggregation are not optimal or suitable for CR based heterogeneous networks(Het Nets). Consequently, the authors propose a novel resource scheduling scheme for spectrum aggregation in CR based Het Nets, termed as cognitive radio based resource scheduling(CR-RS) scheme. CR-RS has a three-level structure. Under a dynamic traffic model, an equivalent throughput of the CCs based on the knowledge of primary users(PUs) is given. On this basis, the CR users data transmission time of each CC is equal in CR-RS. The simulation results show that CR-RS has the better performance than the current resource scheduling schemes in the CR based Het Nets. Meanwhile, CR-RS is also effective in other spectrum aggregation systems which are not CR based HetNets.
基金supported in part by Beijing Natural Science Foundation(4152047)the 863 project No.2014AA01A701+1 种基金111 Project of China under Grant B14010China Mobile Research Institute under grant[2014]451
文摘In this paper,a distributed chunkbased optimization algorithm is proposed for the resource allocation in broadband ultra-dense small cell networks.Based on the proposed algorithm,the power and subcarrier allocation problems are jointly optimized.In order to make the resource allocation suitable for large scale networks,the optimization problem is decomposed first based on an effective decomposition algorithm named optimal condition decomposition(OCD) algorithm.Furthermore,aiming at reducing implementation complexity,the subcarriers are divided into chunks and are allocated chunk by chunk.The simulation results show that the proposed algorithm achieves more superior performance than uniform power allocation scheme and Lagrange relaxation method,and then the proposed algorithm can strike a balance between the complexity and performance of the multi-carrier Ultra-Dense Networks.
基金supported by National Natural Science Foundation of China under Grants No. 61371087 and 61531013The Research Fund of Ministry of Education-China Mobile (MCM20150102)
文摘Cache-enabled small cell networks have been regarded as a promising approach for network operators to cope with the explosive data traffic growth in future 5 G networks. However, the user association and resource allocation mechanism has not been thoroughly studied under given content placement situation. In this paper, we formulate the joint optimization problem of user association and resource allocation as a mixed integer nonlinear programming(MINLP) problem aiming at deriving a balance between the total utility of data rates and the total data rates retrieved from caches. To solve this problem, we propose a distributed relaxing-rounding method. Simulation results demonstrate that the distributed relaxing-rounding method outperforms traditional max-SINR method and range-expansion method in terms of both total utility of data rates and total data rates retrieved from caches in practical scenarios. In addition, effects of storage and backhaul capacities on the performance are also studied.
文摘The approach of traffic abnormality detection of network resource allocation attack did not have reliable signatures to depict abnormality and identify them. However, it is crucial for us to detect attacks accurately. The technique that we adopted is inspired by long range dependence ideas. We use the number of packet arrivals of a flow in fixed-length time intervals as the signal and attempt to extend traffic invariant “self-similarity”. We validate the effectiveness of the approach with simulation and trace analysis.
基金supported by the National Basic Research Program of China(No.2011CB302702)the NationalNatural Science Foundation of China(Nos.60803140,60970133,61070187)
文摘In the Internet of things, it is of critical importance to fully utilize the potential capacity of the network with efficient medium access control (MAC) mechanisms. In this paper, we study the convergence property of the fixed point formulation of distributed coordination function (DCF), which is widely used for medium access control in wireless networks. We first Kind that the fixed point could be repelling, which means that it is impossible for an MAC system to converge at its fixed point. Next, we show the existence of periodic points to prove that the fixed point function will oscillate between two periodic points when the fixed point is repelling. We also find that the average of the two periodic points is a close approximation of the fixed point. Based on the findings, we propose an algorithm to compute the fixed point efficiently. Simulation results verify the accuracy and efficiency of our algorithm compared with the previous fixed point computing method.
文摘Reorganization of network information resources for scientific and technical (scitech for abbreviation) documents and development of information infrastructure have brought a great change in China's scitech documentation information sharing. It integrated not only information resources, but also systems, technologies and funds. High quality services and effective resources sharing are the main goals of the platform construction. The paper describes briefly the principles and aims of the integration of the scitech information resources and networks. The services of the sharing platforms have been also introduced.
文摘In Chinese traditional culture, ceramic culture is a very special cultural system, With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development and utilization is especially important. The idea of Web3.0 make important ceramic culture network native digital resources "reasonable configuration", t o be more embody the value of academic research. In this paper, we'll discuss the conformity utilization of ceramic culture native digital resources based on the concept of WEB3.0.
文摘In Chinese traditional culture, ceramic culture is a very special cultural system With the advent of the era of network and the particularity of ceramic culture, Make the network native digital resources development and utilization is especially important. The idea of Web3.0 make important ceramic culture network native digital resources "reasonable configuration", t o be more embody the value of academic research. In this paper, we'll discuss the conformity utilization of ceramic culture native digital resources based on the concept of WEB3.0.