Mobile communication standards have been developed into a new era of B5G and 6G.In recent years,low earth orbit(LEO)satellites and space Internet have become hot topics.The integrated satellite and terrestrial systems...Mobile communication standards have been developed into a new era of B5G and 6G.In recent years,low earth orbit(LEO)satellites and space Internet have become hot topics.The integrated satellite and terrestrial systems have been widely discussed by industries and academics,and even are expected to be applied in those huge constellations in construction.This paper points out the trends of two stages towards system integration of the terrestrial mobile communication and the satellite communications:to be compatible with 5G,and to be integrated within 6G.Based on analysis of the challenges of both stages,key technologies are thereafter analyzed in detail,covering both air interface currently discussed in 3GPP for B5G and also novel network architecture and related transmission technologies toward future 6G.展开更多
This paper investigated the growth and policy implications of Global System for Mobile Communication in Nigeria. Stochastic economic modeling was used to analyze Nigeria's time series data. The models were adjudged r...This paper investigated the growth and policy implications of Global System for Mobile Communication in Nigeria. Stochastic economic modeling was used to analyze Nigeria's time series data. The models were adjudged reliable before they were used. The components of the model were defined and a prior expectation of the relationship among the variables explained for the purpose of giving the reviewers and users a deep insight into the phenomenon under study. The secondary data used for the study were processed using the E-View for windows electronic packages. The outcome of the empirical and stochastic investigations shows that Global System for Mobile Communication has a positive relationship with output growth in Nigeria. The impact is of a higher magnitude. The usage of Global System for Mobile Telecommunication led to 17 percent rise in the output growth. The findings suggest the need for the Nigerian Communication Commission (NCC) and the federal government of Nigeria to expand tele-density and directly make telephone communications cheap and accessible. To achieve this goal, more licenses should be given to GSM operators in order to allow for healthy competition among them. This will lead to improved quality of services, quality of product and consequently sustain the growth and development of the country.展开更多
A remote antenna unit (RAU) selection model is presented, and two kinds of handoffs, intra-cell handoff (HO) and inter-cell HO, are defined in distributed mobile communications systems (DAS). After that, an inte...A remote antenna unit (RAU) selection model is presented, and two kinds of handoffs, intra-cell handoff (HO) and inter-cell HO, are defined in distributed mobile communications systems (DAS). After that, an inter-cell HO model is proposed, in which the average power of the active set (AS) is used to predict the position of the mobile station (MS). The total power of the AS and the handoff set (HOS) are utilized to determine whether an inter-cell HO is necessary. Furthermore, the relationship between HO parameters and performance metrics is studied in detail based on RAU selection. Simulation results show that both the intra-cell HO and the inter-cell HO can achieve oerfect performance by aoprooriate settings of HO parameters.展开更多
With the increasing maritime activities and the rapidly developing maritime economy, the fifth-generation(5G) mobile communication system is expected to be deployed at the ocean. New technologies need to be explored t...With the increasing maritime activities and the rapidly developing maritime economy, the fifth-generation(5G) mobile communication system is expected to be deployed at the ocean. New technologies need to be explored to meet the requirements of ultra-reliable and low latency communications(URLLC) in the maritime communication network(MCN). Mobile edge computing(MEC) can achieve high energy efficiency in MCN at the cost of suffering from high control plane latency and low reliability. In terms of this issue, the mobile edge communications, computing, and caching(MEC3) technology is proposed to sink mobile computing, network control, and storage to the edge of the network. New methods that enable resource-efficient configurations and reduce redundant data transmissions can enable the reliable implementation of computing-intension and latency-sensitive applications. The key technologies of MEC3 to enable URLLC are analyzed and optimized in MCN. The best response-based offloading algorithm(BROA) is adopted to optimize task offloading. The simulation results show that the task latency can be decreased by 26.5’ ms, and the energy consumption in terminal users can be reduced to 66.6%.展开更多
Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell ra...Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs.展开更多
This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G)....This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chinese mobile network operators are given based on the analysis.展开更多
In order to forecast promising technologies in the field of next generation mobile communication, various patent indicators were analyzed such as citation per patent, patent family information, patent share, increase ...In order to forecast promising technologies in the field of next generation mobile communication, various patent indicators were analyzed such as citation per patent, patent family information, patent share, increase rate, and patent activity. These indicators were quantified into several indexes and then integrated into an evaluation score to provide promising technologies. As a result of the suggested patent analysis, four technologies out of twenty two in details classification were selected, which showed outstanding technology competitiveness, high patent share and increasing rates as well as high recent-patent-ratios and triad-patent-family-ratios. Each of the selected technologies scored more than 10 points in total, and the following four technologies were suggested as promising ones in the field of next generation mobile communication: 1) 3GPP based mobile communication, 2) beyond 4G mobile communication, 3) IEEE 802.16 based mobile communication, which are in medium classification of broadband mobile communication system, and 4) testing/certification system of mobile communication, which is in medium classification of mobile communication testing/certification system.展开更多
The working of a Mobile Ad hoc NETwork(MANET)relies on the supportive cooperation among the network nodes.But due to its intrinsic features,a misbehaving node can easily lead to a routing disorder.This paper presents ...The working of a Mobile Ad hoc NETwork(MANET)relies on the supportive cooperation among the network nodes.But due to its intrinsic features,a misbehaving node can easily lead to a routing disorder.This paper presents two trust-based routing schemes,namely Trust-based Self-Detection Routing(TSDR)and Trust-based Cooperative Routing(TCOR)designed with an Ad hoc On-demand Distance Vector(AODV)protocol.The proposed work covers a wide range of security challenges,including malicious node identification and prevention,accurate trust quantification,secure trust data sharing,and trusted route maintenance.This brings a prominent solution for mitigating misbehaving nodes and establishing efficient communication in MANET.It is empirically validated based on a performance comparison with the current Evolutionary Self-Cooperative Trust(ESCT)scheme,Generalized Trust Model(GTM),and the conventional AODV protocol.The extensive simulations are conducted against three different varying network scenarios.The results affirm the improved values of eight popular performance metrics overcoming the existing routing schemes.Among the two proposed works,TCOR is more suitable for highly scalable networks;TSDR suits,however,the MANET application better with its small size.This work thus makes a significant contribution to the research community,in contrast to many previous works focusing solely on specific security aspects,and results in a trade-off in the expected values of evaluation parameters and asserts their efficiency.展开更多
In view of the many scenes of unmanned aerial vehicle(UAV)detection,a third-party signal source is used to design a receiver to monitor the UAV.It is of great significance to understand the reflection of the signal il...In view of the many scenes of unmanned aerial vehicle(UAV)detection,a third-party signal source is used to design a receiver to monitor the UAV.It is of great significance to understand the reflection of the signal illuminating the UAV.Taking the communication base station(BS)signal as the third-party signal source,and considering the complete transmission link,reflection changes and loss fading of the communication signal,this study conducts model fitting for irregular UAV targets,simplifying complex targets into a combination of simple targets.Furthermore,the influence of the dielectric constant of the target surface and the signal irradiation angle on the signal reflection is analyzed.The analysis shows that the simulation results of this model fitting method are consistent with the results of other literature,which provides theoretical support for the detection of low and slow small targets such as UAVs.展开更多
Control signaling is mandatory for the operation and management of all types of communication networks,including the Third Generation Partnership Project(3GPP)mobile broadband networks.However,they consume important a...Control signaling is mandatory for the operation and management of all types of communication networks,including the Third Generation Partnership Project(3GPP)mobile broadband networks.However,they consume important and scarce network resources such as bandwidth and processing power.There have been several reports of these control signaling turning into signaling storms halting network operations and causing the respective Telecom companies big financial losses.This paper draws its motivation from such real network disaster incidents attributed to signaling storms.In this paper,we present a thorough survey of the causes,of the signaling storm problems in 3GPP-based mobile broadband networks and discuss in detail their possible solutions and countermeasures.We provide relevant analytical models to help quantify the effect of the potential causes and benefits of their corresponding solutions.Another important contribution of this paper is the comparison of the possible causes and solutions/countermeasures,concerning their effect on several important network aspects such as architecture,additional signaling,fidelity,etc.,in the form of a table.This paper presents an update and an extension of our earlier conference publication.To our knowledge,no similar survey study exists on the subject.展开更多
The widespread use of advanced electronic devices has led to the emergence of spatial crowdsourcing,a method that taps into collective efforts to perform real-world tasks like environmental monitoring and traffic surv...The widespread use of advanced electronic devices has led to the emergence of spatial crowdsourcing,a method that taps into collective efforts to perform real-world tasks like environmental monitoring and traffic surveillance.Our research focuses on a specific type of spatial crowdsourcing that involves ongoing,collaborative efforts for continuous spatial data acquisition.However,due to limited budgets and workforce availability,the collected data often lacks completeness,posing a data deficiency problem.To address this,we propose a reciprocal framework to optimize task assignments by leveraging the mutual benefits of spatiotemporal subtask execution.We introduce an entropy-based quality metric to capture the combined effects of incomplete data acquisition and interpolation imprecision.Building on this,we explore a quality-aware task assignment method,corresponding to spatiotemporal assignment strategies.Since the assignment problem is NP-hard,we develop a polynomial-time algorithm with the guaranteed approximation ratio.Novel indexing and pruning techniques are proposed to further enhance performance.Extensive experiments conducted on datasets validate the effectiveness of our methods.展开更多
As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communicat...As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communication performance of underwater quantum links,based on the extinction characteristics of marine planktonic algal particles,the influence of changes in the chlorophyll concentration and particle number density of planktonic algal particles on the attenuation of underwater links is explored respectively,the influence of marine planktonic algal particles on the fidelity of underwater quantum links,the generation rate of the security key,and the utilization rate of the channel is analyzed,and simulation experiments are carried out.The results show that with the increase in chlorophyll concentration and particle density of aquatic planktonic algal particles,quantum communication channel link attenuation shows a gradually increasing trend.In addition,the security key generation rate,channel fidelity and utilization rate are gradually decreasing.Therefore,the performance of underwater quantum communication channel will be interfered by marine planktonic algal particles,and it is necessary to adjust the relevant parameter values in the quantum communication system according to different marine planktonic algal particle number density and chlorophyll concentration to improve the performance of quantum communication.展开更多
Based on improved Cournot model and Stackelberg model,this paper analyzes the firstmover advantage of China Mobile which is in a dominant position;then,by using complete information dynamic game,this paper analyzes th...Based on improved Cournot model and Stackelberg model,this paper analyzes the firstmover advantage of China Mobile which is in a dominant position;then,by using complete information dynamic game,this paper analyzes the market shares of the oligarchic monopoly market of the mobile communications industry before the restructuring of the telecom industry and tests the analysis conclusion;at the same time,this paper analyzes the market shares in initial stage and mature stage of the mobile communications market after the restructuring.According to the analysis of this paper,China Mobile's market share will drop after the restructuring,the restructuring has a certain effect,but China Mobile is still in a leading position.Whether the duopoly market before the restructuring or the three oligopoly market after the restructuring,every mobile operator has a relatively fixed market share under stable condition.This shows that mobile operators in China should cooperate on the basis of competition when developing the domestic market,and explore the international market to achieve greater development.展开更多
Since 2000 mobile communications have undergoneextremely fast growth in Russia with a penetration ratefar surpassing China. In October 2007, Russian 3Gmobile communications networks were formallylaunched for commercia...Since 2000 mobile communications have undergoneextremely fast growth in Russia with a penetration ratefar surpassing China. In October 2007, Russian 3Gmobile communications networks were formallylaunched for commercial operation. This article attempts to bring forth some suggestions for China’s 3Gmobile communications development through a studyof the Russian mobile migration process from 2G to 3G.展开更多
Telecommunications Regulatory Commission of Sri Lanka is the governing body which is responsible for the frequency allocation and monitoring the unauthorized Electromagnetic frequency(EMF)signal transmitting violation...Telecommunications Regulatory Commission of Sri Lanka is the governing body which is responsible for the frequency allocation and monitoring the unauthorized Electromagnetic frequency(EMF)signal transmitting violations.However,in Sri Lanka,currently there is not any proper mechanism to monitor the radiation hazard level and its impact to the people living in the vicinity of mobile communication towers.There are approximately 7000 mobile transmitting towers in Sri Lanka to date and the used frequency range lies between 900 MHz to 3 GHz for mobile communication.Over the last few decades,many of the health hazard conditions were reported due to the radiation of those harmful EMFs.To cater this problem,a portable real time EMF signal strength measuring system with a radiation hazard level indicator was developed to monitor the EMF level and its impact.The proposed system operates with three intermediate frequency bands(i.e.900 MHz,1800 MHz and 2400 MHz)and it’s capable of measuring the power density and the radiation hazard level at that particular point which is being measured.Moreover,the corresponding radiation hazard level is indicated with reference to the standard power density levels published by the International Commission on Non-Ionizing Radiation Protection(ICNIRP^(*)).The system works with the overall accuracy of 88%in terms of identifying the power densities and its corresponding radiation hazard levels.展开更多
This paper studies the communication protocol and link establishing mode of the mine managing mobile communication system consisted of minute areas. The communication protocol suitable for the system is proposed and d...This paper studies the communication protocol and link establishing mode of the mine managing mobile communication system consisted of minute areas. The communication protocol suitable for the system is proposed and designed.展开更多
The tracking and stable control of a typical shipmounted mobile satellite communication system(MSCS) is studied.Unlike the former studies based on simplified single-axis models,a tri-axis nonlinear model including t...The tracking and stable control of a typical shipmounted mobile satellite communication system(MSCS) is studied.Unlike the former studies based on simplified single-axis models,a tri-axis nonlinear model including the kinematic and dynamic features of the MSCS is used as the control object.An adaptive robust controller with trajectory planning is designed to deal with large parametric uncertainties and uncertain nonlinearities of the system.A theoretic performance result is given and proved.The designed adaptive robust controller and other two traditional controllers are tested in the comparative simulations under three different situations.The simulation results show the tracking and stable validity of the proposed controller.展开更多
Turbo code has been shown to have ability to achieve performance that is close to Shannon limit. It has been adopted by various commercial communication systems. Both universal mobile telecommunications system (UMTS) ...Turbo code has been shown to have ability to achieve performance that is close to Shannon limit. It has been adopted by various commercial communication systems. Both universal mobile telecommunications system (UMTS) TDD and FDD have also employed turbo code as the error correction coding scheme. It outperforms convolutional code in large block size, but because of its time delay, it is often only used in the non-real-time service. In this paper, we discuss the encoder and decoder structure of turbo code in B3G mobile communication System. In addition, various decoding techniques, such as the Log-MAP, Max-log-MAP and SOVA algorithm for non-real-time service are deduced and compared. The performance results of decoder and algorithms in different configurations are also shown.展开更多
With the operation of the CUC(China Unicom CorporationLtd.)“New Horizon”CD-MA network, the Chinesemobile communication market hasentered a new stage of development.GSM and CDMA have joined handsto work fully and eff...With the operation of the CUC(China Unicom CorporationLtd.)“New Horizon”CD-MA network, the Chinesemobile communication market hasentered a new stage of development.GSM and CDMA have joined handsto work fully and efficiently. The to-展开更多
CDMA2000 1×EV-DO is an advancedtechnology optimized for high ratewireless data services that arecharacterized by burstness, high speed,asymmetric uplink and downlink data rateand insensitiveness to time delay. It...CDMA2000 1×EV-DO is an advancedtechnology optimized for high ratewireless data services that arecharacterized by burstness, high speed,asymmetric uplink and downlink data rateand insensitiveness to time delay. It has thefollowing advantages:(1)Data OptimizationCDMA2000 1×EV-DO, a data-optimizedversion of CDMA2000, delivers a forward peakdata rate of up to 2.4576 Mb/s within a 1.25 MHz展开更多
基金This work was supported in part by the National Science Fund for Distinguished Young Scholars in China under grant 61425012the National Science Foundation Project in China under grant 61931005 and 61731017.
文摘Mobile communication standards have been developed into a new era of B5G and 6G.In recent years,low earth orbit(LEO)satellites and space Internet have become hot topics.The integrated satellite and terrestrial systems have been widely discussed by industries and academics,and even are expected to be applied in those huge constellations in construction.This paper points out the trends of two stages towards system integration of the terrestrial mobile communication and the satellite communications:to be compatible with 5G,and to be integrated within 6G.Based on analysis of the challenges of both stages,key technologies are thereafter analyzed in detail,covering both air interface currently discussed in 3GPP for B5G and also novel network architecture and related transmission technologies toward future 6G.
文摘This paper investigated the growth and policy implications of Global System for Mobile Communication in Nigeria. Stochastic economic modeling was used to analyze Nigeria's time series data. The models were adjudged reliable before they were used. The components of the model were defined and a prior expectation of the relationship among the variables explained for the purpose of giving the reviewers and users a deep insight into the phenomenon under study. The secondary data used for the study were processed using the E-View for windows electronic packages. The outcome of the empirical and stochastic investigations shows that Global System for Mobile Communication has a positive relationship with output growth in Nigeria. The impact is of a higher magnitude. The usage of Global System for Mobile Telecommunication led to 17 percent rise in the output growth. The findings suggest the need for the Nigerian Communication Commission (NCC) and the federal government of Nigeria to expand tele-density and directly make telephone communications cheap and accessible. To achieve this goal, more licenses should be given to GSM operators in order to allow for healthy competition among them. This will lead to improved quality of services, quality of product and consequently sustain the growth and development of the country.
基金The National Natural Science Foundation of China(No60496311)
文摘A remote antenna unit (RAU) selection model is presented, and two kinds of handoffs, intra-cell handoff (HO) and inter-cell HO, are defined in distributed mobile communications systems (DAS). After that, an inter-cell HO model is proposed, in which the average power of the active set (AS) is used to predict the position of the mobile station (MS). The total power of the AS and the handoff set (HOS) are utilized to determine whether an inter-cell HO is necessary. Furthermore, the relationship between HO parameters and performance metrics is studied in detail based on RAU selection. Simulation results show that both the intra-cell HO and the inter-cell HO can achieve oerfect performance by aoprooriate settings of HO parameters.
基金the National S&T Major Project (No. 2018ZX03001011)the National Key R&D Program(No.2018YFB1801102)+1 种基金the National Natural Science Foundation of China (No. 61671072)the Beijing Natural Science Foundation (No. L192025)
文摘With the increasing maritime activities and the rapidly developing maritime economy, the fifth-generation(5G) mobile communication system is expected to be deployed at the ocean. New technologies need to be explored to meet the requirements of ultra-reliable and low latency communications(URLLC) in the maritime communication network(MCN). Mobile edge computing(MEC) can achieve high energy efficiency in MCN at the cost of suffering from high control plane latency and low reliability. In terms of this issue, the mobile edge communications, computing, and caching(MEC3) technology is proposed to sink mobile computing, network control, and storage to the edge of the network. New methods that enable resource-efficient configurations and reduce redundant data transmissions can enable the reliable implementation of computing-intension and latency-sensitive applications. The key technologies of MEC3 to enable URLLC are analyzed and optimized in MCN. The best response-based offloading algorithm(BROA) is adopted to optimize task offloading. The simulation results show that the task latency can be decreased by 26.5’ ms, and the energy consumption in terminal users can be reduced to 66.6%.
基金supported in part by the National Natural Science Foundation of China under Grant No.61671145the Key R&D Program of Jiangsu Province of China under Grant BE2018121
文摘Millimeter-wave(mm Wave) communications will be used in fifth-generation(5G) mobile communication systems, but they experience severe path loss and have high sensitivity to physical objects, leading to smaller cell radii and complicated network architectures. A coverage extension scheme using large-scale antenna arrays(LSAAs) has been suggested and theoretically proven to be cost-efficient in combination with ultradense small cell networks. To analyze and optimize the LSAA-based network deployments, a comprehensive survey of recent advances in statistical mmWave channel modeling is first presented in terms of channel parameter estimation, large-scale path loss models, and small-scale cluster models. Next, the measurement and modeling results at two 5G candidate mmWave bands(e.g., 28 GHz and 39 GHz) are reviewed and compared in several outdoor scenarios of interest, where the propagation characteristics make crucial contributions to wireless network designs. Finally, the coverage behaviors of systems employing a large number of antenna arrays are discussed, as well as some implications on future mmWave cellular network designs.
文摘This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chinese mobile network operators are given based on the analysis.
文摘In order to forecast promising technologies in the field of next generation mobile communication, various patent indicators were analyzed such as citation per patent, patent family information, patent share, increase rate, and patent activity. These indicators were quantified into several indexes and then integrated into an evaluation score to provide promising technologies. As a result of the suggested patent analysis, four technologies out of twenty two in details classification were selected, which showed outstanding technology competitiveness, high patent share and increasing rates as well as high recent-patent-ratios and triad-patent-family-ratios. Each of the selected technologies scored more than 10 points in total, and the following four technologies were suggested as promising ones in the field of next generation mobile communication: 1) 3GPP based mobile communication, 2) beyond 4G mobile communication, 3) IEEE 802.16 based mobile communication, which are in medium classification of broadband mobile communication system, and 4) testing/certification system of mobile communication, which is in medium classification of mobile communication testing/certification system.
文摘The working of a Mobile Ad hoc NETwork(MANET)relies on the supportive cooperation among the network nodes.But due to its intrinsic features,a misbehaving node can easily lead to a routing disorder.This paper presents two trust-based routing schemes,namely Trust-based Self-Detection Routing(TSDR)and Trust-based Cooperative Routing(TCOR)designed with an Ad hoc On-demand Distance Vector(AODV)protocol.The proposed work covers a wide range of security challenges,including malicious node identification and prevention,accurate trust quantification,secure trust data sharing,and trusted route maintenance.This brings a prominent solution for mitigating misbehaving nodes and establishing efficient communication in MANET.It is empirically validated based on a performance comparison with the current Evolutionary Self-Cooperative Trust(ESCT)scheme,Generalized Trust Model(GTM),and the conventional AODV protocol.The extensive simulations are conducted against three different varying network scenarios.The results affirm the improved values of eight popular performance metrics overcoming the existing routing schemes.Among the two proposed works,TCOR is more suitable for highly scalable networks;TSDR suits,however,the MANET application better with its small size.This work thus makes a significant contribution to the research community,in contrast to many previous works focusing solely on specific security aspects,and results in a trade-off in the expected values of evaluation parameters and asserts their efficiency.
基金supported by the State Major Research and Development Project(2018YFB1802004)the State Key Laboratory of Air Traffic Management System and Technology(SKLATM201807)。
文摘In view of the many scenes of unmanned aerial vehicle(UAV)detection,a third-party signal source is used to design a receiver to monitor the UAV.It is of great significance to understand the reflection of the signal illuminating the UAV.Taking the communication base station(BS)signal as the third-party signal source,and considering the complete transmission link,reflection changes and loss fading of the communication signal,this study conducts model fitting for irregular UAV targets,simplifying complex targets into a combination of simple targets.Furthermore,the influence of the dielectric constant of the target surface and the signal irradiation angle on the signal reflection is analyzed.The analysis shows that the simulation results of this model fitting method are consistent with the results of other literature,which provides theoretical support for the detection of low and slow small targets such as UAVs.
基金the Deanship of Graduate Studies and Scientific Research at Qassim University for financial support(QU-APC-2024-9/1).
文摘Control signaling is mandatory for the operation and management of all types of communication networks,including the Third Generation Partnership Project(3GPP)mobile broadband networks.However,they consume important and scarce network resources such as bandwidth and processing power.There have been several reports of these control signaling turning into signaling storms halting network operations and causing the respective Telecom companies big financial losses.This paper draws its motivation from such real network disaster incidents attributed to signaling storms.In this paper,we present a thorough survey of the causes,of the signaling storm problems in 3GPP-based mobile broadband networks and discuss in detail their possible solutions and countermeasures.We provide relevant analytical models to help quantify the effect of the potential causes and benefits of their corresponding solutions.Another important contribution of this paper is the comparison of the possible causes and solutions/countermeasures,concerning their effect on several important network aspects such as architecture,additional signaling,fidelity,etc.,in the form of a table.This paper presents an update and an extension of our earlier conference publication.To our knowledge,no similar survey study exists on the subject.
文摘The widespread use of advanced electronic devices has led to the emergence of spatial crowdsourcing,a method that taps into collective efforts to perform real-world tasks like environmental monitoring and traffic surveillance.Our research focuses on a specific type of spatial crowdsourcing that involves ongoing,collaborative efforts for continuous spatial data acquisition.However,due to limited budgets and workforce availability,the collected data often lacks completeness,posing a data deficiency problem.To address this,we propose a reciprocal framework to optimize task assignments by leveraging the mutual benefits of spatiotemporal subtask execution.We introduce an entropy-based quality metric to capture the combined effects of incomplete data acquisition and interpolation imprecision.Building on this,we explore a quality-aware task assignment method,corresponding to spatiotemporal assignment strategies.Since the assignment problem is NP-hard,we develop a polynomial-time algorithm with the guaranteed approximation ratio.Novel indexing and pruning techniques are proposed to further enhance performance.Extensive experiments conducted on datasets validate the effectiveness of our methods.
基金funded by Youth Fund of the National Natural Science Foundation of China,grant number 11504176,61601230.
文摘As one of the main application directions of quantum technology,underwater quantum communication is of great research significance.In order to study the influence of marine planktonic algal particles on the communication performance of underwater quantum links,based on the extinction characteristics of marine planktonic algal particles,the influence of changes in the chlorophyll concentration and particle number density of planktonic algal particles on the attenuation of underwater links is explored respectively,the influence of marine planktonic algal particles on the fidelity of underwater quantum links,the generation rate of the security key,and the utilization rate of the channel is analyzed,and simulation experiments are carried out.The results show that with the increase in chlorophyll concentration and particle density of aquatic planktonic algal particles,quantum communication channel link attenuation shows a gradually increasing trend.In addition,the security key generation rate,channel fidelity and utilization rate are gradually decreasing.Therefore,the performance of underwater quantum communication channel will be interfered by marine planktonic algal particles,and it is necessary to adjust the relevant parameter values in the quantum communication system according to different marine planktonic algal particle number density and chlorophyll concentration to improve the performance of quantum communication.
文摘Based on improved Cournot model and Stackelberg model,this paper analyzes the firstmover advantage of China Mobile which is in a dominant position;then,by using complete information dynamic game,this paper analyzes the market shares of the oligarchic monopoly market of the mobile communications industry before the restructuring of the telecom industry and tests the analysis conclusion;at the same time,this paper analyzes the market shares in initial stage and mature stage of the mobile communications market after the restructuring.According to the analysis of this paper,China Mobile's market share will drop after the restructuring,the restructuring has a certain effect,but China Mobile is still in a leading position.Whether the duopoly market before the restructuring or the three oligopoly market after the restructuring,every mobile operator has a relatively fixed market share under stable condition.This shows that mobile operators in China should cooperate on the basis of competition when developing the domestic market,and explore the international market to achieve greater development.
文摘Since 2000 mobile communications have undergoneextremely fast growth in Russia with a penetration ratefar surpassing China. In October 2007, Russian 3Gmobile communications networks were formallylaunched for commercial operation. This article attempts to bring forth some suggestions for China’s 3Gmobile communications development through a studyof the Russian mobile migration process from 2G to 3G.
文摘Telecommunications Regulatory Commission of Sri Lanka is the governing body which is responsible for the frequency allocation and monitoring the unauthorized Electromagnetic frequency(EMF)signal transmitting violations.However,in Sri Lanka,currently there is not any proper mechanism to monitor the radiation hazard level and its impact to the people living in the vicinity of mobile communication towers.There are approximately 7000 mobile transmitting towers in Sri Lanka to date and the used frequency range lies between 900 MHz to 3 GHz for mobile communication.Over the last few decades,many of the health hazard conditions were reported due to the radiation of those harmful EMFs.To cater this problem,a portable real time EMF signal strength measuring system with a radiation hazard level indicator was developed to monitor the EMF level and its impact.The proposed system operates with three intermediate frequency bands(i.e.900 MHz,1800 MHz and 2400 MHz)and it’s capable of measuring the power density and the radiation hazard level at that particular point which is being measured.Moreover,the corresponding radiation hazard level is indicated with reference to the standard power density levels published by the International Commission on Non-Ionizing Radiation Protection(ICNIRP^(*)).The system works with the overall accuracy of 88%in terms of identifying the power densities and its corresponding radiation hazard levels.
基金The project supported by Coal Science and Doctor Subject Foundation
文摘This paper studies the communication protocol and link establishing mode of the mine managing mobile communication system consisted of minute areas. The communication protocol suitable for the system is proposed and designed.
基金supported by the National Natural Science Foundation of China (61074023,60975075)the Natural Science Foundation of Jiangsu Province of China (BK2008404)+1 种基金the Science and Technology Pillar Program of Jiangsu Province of China (BE2009160)the Innovation Project of Graduate Students of Jiangsu Province of China(CXZZ 0254)
文摘The tracking and stable control of a typical shipmounted mobile satellite communication system(MSCS) is studied.Unlike the former studies based on simplified single-axis models,a tri-axis nonlinear model including the kinematic and dynamic features of the MSCS is used as the control object.An adaptive robust controller with trajectory planning is designed to deal with large parametric uncertainties and uncertain nonlinearities of the system.A theoretic performance result is given and proved.The designed adaptive robust controller and other two traditional controllers are tested in the comparative simulations under three different situations.The simulation results show the tracking and stable validity of the proposed controller.
文摘Turbo code has been shown to have ability to achieve performance that is close to Shannon limit. It has been adopted by various commercial communication systems. Both universal mobile telecommunications system (UMTS) TDD and FDD have also employed turbo code as the error correction coding scheme. It outperforms convolutional code in large block size, but because of its time delay, it is often only used in the non-real-time service. In this paper, we discuss the encoder and decoder structure of turbo code in B3G mobile communication System. In addition, various decoding techniques, such as the Log-MAP, Max-log-MAP and SOVA algorithm for non-real-time service are deduced and compared. The performance results of decoder and algorithms in different configurations are also shown.
文摘With the operation of the CUC(China Unicom CorporationLtd.)“New Horizon”CD-MA network, the Chinesemobile communication market hasentered a new stage of development.GSM and CDMA have joined handsto work fully and efficiently. The to-
文摘CDMA2000 1×EV-DO is an advancedtechnology optimized for high ratewireless data services that arecharacterized by burstness, high speed,asymmetric uplink and downlink data rateand insensitiveness to time delay. It has thefollowing advantages:(1)Data OptimizationCDMA2000 1×EV-DO, a data-optimizedversion of CDMA2000, delivers a forward peakdata rate of up to 2.4576 Mb/s within a 1.25 MHz