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
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
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
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
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
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
For the purpose of making the best use of the mine frequency resource and realizing the instruction idea “to exchange bandwidth for distance" a W-CDMA mine spread spectrum mobile communication scheme based on sp...For the purpose of making the best use of the mine frequency resource and realizing the instruction idea “to exchange bandwidth for distance" a W-CDMA mine spread spectrum mobile communication scheme based on spread spectrum communication technique and the propagation characteristic of electromagnetic wave along laneways is proposed.The structure and make up of the system are studied and the working frequency and channels are assigned.Analysis indicates the scheme is a simple one that can fulfill the mine saying requirement.展开更多
With the further reduction in cost and the increase in bandwidth, as well as the increase in internet applications, satellite communications are gradually shifting from a complementary role to becoming a fully integra...With the further reduction in cost and the increase in bandwidth, as well as the increase in internet applications, satellite communications are gradually shifting from a complementary role to becoming a fully integrated component of terrestrial communications networks. This paper firstly introduces the development of satellite communications, mobile communications and the global space-terrestrial integrated network. We then propose the functional architecture and network architecture for the integration of satellite communications and terrestrial mobile communications based on 5 G core networks. Finally, in order to support the network of the future, four key technologies are presented, a space-terrestrial integrated air interface design, a multi-band space-terrestrial integrated transmission waveform design, space-terrestrial integrated switching and routing technology, along with spectrum sharing and interference coordination technology, all necessary for the development of space-terrestrial integrated networks.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
This article presents the generation of Orbital AngularMomentum(OAM)vortex waves with mode 1 using Uniform Circular Array(UCA)antenna.Two different designs,namely,UCA-1(4-element array antenna)and UCA-2(8-element arra...This article presents the generation of Orbital AngularMomentum(OAM)vortex waves with mode 1 using Uniform Circular Array(UCA)antenna.Two different designs,namely,UCA-1(4-element array antenna)and UCA-2(8-element array antenna),were designed and fabricated using FR-4 substrate to generate OAM mode 1 at 3.5 GHz(5G mid-band).The proposed antenna arrays comprised rectangular microstrip patch elements with inset fed technique.The elements were excited by a carefully designed feeding phase shift network to provide similar output energy at output ports with desired phase shift value.The generated OAM waves were confirmed by measuring the null in the bore sight of their 2D radiation patterns,simulated phase distribution and intensity distribution.The measurement results agree well with the simulation results.Moreover,a detailed mode purity analysis of the generated OAM waves was carried out considering different factors.The investigation found that the greater the number of elements,the higher the purity of the generated OAM wave.Compared with other previous works,the proposed antenna design of this paper is very simple to design and fabricate.In addition,the proposed antennas are compact in design even at lower frequency band with very wide bandwidth to meet the requirements of 5G mid-band applications.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
The programmable metasurface(PM)is an antenna array architecture that realizes flexible beam steering.This functionality is achieved by controlling the unit cells designed with micro components such as positive-intrin...The programmable metasurface(PM)is an antenna array architecture that realizes flexible beam steering.This functionality is achieved by controlling the unit cells designed with micro components such as positive-intrinsic-negative(PIN)diodes,which offers potential cost reductions in the next generation wireless communication systems.Although PM has been a popular topic in antenna design,its implementations in real-time systems accompanied by signal processing algorithms are challenging.In this paper,novel predictive tracking algorithms for mobile communication scenarios using a PM are created and implemented in a real-time system operating at 28 GHz.An angular speed prediction(ASP)algorithm is proposed to compute the position of user equipment(UE)based on the previously recorded beam directions.As another solution,an angle correction(AC)algorithm is proposed to further improve the prediction and tracking accuracy.As a benchmark,the comparisons to a previous PM tracking algorithm without prediction are presented.Both simulation and measurement results show that the prediction algorithms successfully improve the tracking performance,which also prove the feasibilities of PM-based systems to solve complex real-time signal processing problems.展开更多
5G is a new generation of mobile networking that aims to achieve unparalleled speed and performance. To accomplish this, three technologies, Device-to-Device communication (D2D), multi-access edge computing (MEC) and ...5G is a new generation of mobile networking that aims to achieve unparalleled speed and performance. To accomplish this, three technologies, Device-to-Device communication (D2D), multi-access edge computing (MEC) and network function virtualization (NFV) with ClickOS, have been a significant part of 5G, and this paper mainly discusses them. D2D enables direct communication between devices without the relay of base station. In 5G, a two-tier cellular network composed of traditional cellular network system and D2D is an efficient method for realizing high-speed communication. MEC unloads work from end devices and clouds platforms to widespread nodes, and connects the nodes together with outside devices and third-party providers, in order to diminish the overloading effect on any device caused by enormous applications and improve users’ quality of experience (QoE). There is also a NFV method in order to fulfill the 5G requirements. In this part, an optimized virtual machine for middle-boxes named ClickOS is introduced, and it is evaluated in several aspects. Some middle boxes are being implemented in the ClickOS and proved to have outstanding performances.展开更多
Objectives:The uses of devices of electromagnetic waves(EMWs)are increasing day by day.Similarly,the generation of the waves is increasing.The frequency spectrum of the generation of waves is also increased.In this ma...Objectives:The uses of devices of electromagnetic waves(EMWs)are increasing day by day.Similarly,the generation of the waves is increasing.The frequency spectrum of the generation of waves is also increased.In this manuscript,an analysis of the high frequency EMWs has been made by the electric fields generated due to the exposure of 5th generation(5 G)of mobile phones.Methods:Due to the emission of waves from the towers,the electric field is generated around the transmission tower of mobile phones.The electric fields are computed by the power of the transmission tower.The electric fields across the biological tissues/cells are also computed when the EMWs penetrate inside the body.The electric fields are made across the organs of different depths inside the body.Results:The induced electric fields inside the organs of the human beings are responsible for the absorption of energy from high frequency EMWs.The absorbed amount of energy from high frequency waves may become the cause of harmful effects on the life of organs of human beings.Conclusion:In this manuscript,after analysis of the computed electric fields inside the organs of human beings,it is concluded that the EMWs of 5 G spectrum of mobile phone towers may more harmful for the life of organs as 4th generation(4 G)spectrum of mobile phone waves.The energy absorption by the 4 G spectrum is lower than 5 G spectrum due to the range of frequency of waves.The effects on the pancreas,retina,skin,intestine,spleen,stomach and uterus are more than low water content organs like nails,bone,teeth etc.展开更多
Based on the characteristics of the radio propagation in land mobile communications environment, a theoretical model for the reflecting(scattering) number of each radio path is derived firstly. This model can be used ...Based on the characteristics of the radio propagation in land mobile communications environment, a theoretical model for the reflecting(scattering) number of each radio path is derived firstly. This model can be used to predict the variation of radio path strength, which is important for practical mobile communications engineering. Using this model, a method for simulating radio path strength is developed, with numerical results presented.展开更多
In the paper, we illustrate the importance of the concept of mobile network computer from a technological perspective. Because of the usefulness of mobile network computers, with the growth of the Internet of things, ...In the paper, we illustrate the importance of the concept of mobile network computer from a technological perspective. Because of the usefulness of mobile network computers, with the growth of the Internet of things, mobile network computers may include not only TV box audio-visual equipment, wireless household appliances, and mobile communication equipment, but may also include devices such as intelligent foot rings, smart watches, smart glasses, smart shoes and smart coats. Considering the different types of networks, e.g. IP multimedia Subsystem(IMS), we explain why some network elements are inaccurate and misleading from a technological perspective. We aim to popularize the concept of mobile network computers for its accuracy and importance, which better define modern mobile terminals and reflects the nature of multiple mobile terminals based on the structure of their integrated computers and the capabilities of processing multimedia. In the computer and Internet age, network computers and mobile network computers are the main terminals of fixed and mobile networks, respectively. Therefore, based on the concept of mobile network computers, we discuss the future of information society.展开更多
Fifth Generation(5G)communications are regarded as the cornerstone to household consumer experience improvements and smart manufacturing revolution from the standpoint of industries’objectives.It is anticipated that ...Fifth Generation(5G)communications are regarded as the cornerstone to household consumer experience improvements and smart manufacturing revolution from the standpoint of industries’objectives.It is anticipated that Envisaged 5G(E5G)mobile technology would be operational in certain developed countries by 2023.The Internet of Things(IoTs)will transform how humans live when combined with smart and integrated sensing devices,such as in-home sensing devices.Recent research is being carried out all over the world to produce a new technique that can be crucial in the success of the anticipated 5G mobile technology.High output,reduced latency,highly reliable,greater scalability,high performance,capacity,bandwidth efficiency,virtual open-air transmission,and efficient energy mobile wireless communications are all being investigated currently.In this work,a comprehensive path for addressing the difficulties and developments associated with 5G mobile technology is provided.The debate and description of a complete analysis of current situations,certain characteristics and prospective scenarios,important technologies,problems and advances,and spectrum allocation of envisioned 5G mobile technologies are provided.Furthermore,this paper analyzes the most notable elements of 5G mobile technology,such as Cognitive Radio(CR),flexibility,accessibility,and cloud-based service offers,which will assure 5G mobile technology’s dominance as the main protocol for international communication.Eventually,this paper provides a method for integrating CR with current wireless communication systems,the necessity for further evolution of the E5G network,and the need for comprehensive consideration of architecture evolution and function enhancement to enhance the E5G mobile technologies.展开更多
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.
文摘For the purpose of making the best use of the mine frequency resource and realizing the instruction idea “to exchange bandwidth for distance" a W-CDMA mine spread spectrum mobile communication scheme based on spread spectrum communication technique and the propagation characteristic of electromagnetic wave along laneways is proposed.The structure and make up of the system are studied and the working frequency and channels are assigned.Analysis indicates the scheme is a simple one that can fulfill the mine saying requirement.
文摘With the further reduction in cost and the increase in bandwidth, as well as the increase in internet applications, satellite communications are gradually shifting from a complementary role to becoming a fully integrated component of terrestrial communications networks. This paper firstly introduces the development of satellite communications, mobile communications and the global space-terrestrial integrated network. We then propose the functional architecture and network architecture for the integration of satellite communications and terrestrial mobile communications based on 5 G core networks. Finally, in order to support the network of the future, four key technologies are presented, a space-terrestrial integrated air interface design, a multi-band space-terrestrial integrated transmission waveform design, space-terrestrial integrated switching and routing technology, along with spectrum sharing and interference coordination technology, all necessary for the development of space-terrestrial integrated networks.
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supported by Ministry of Higher Education through the FundamentalResearch Grant Scheme(FRGS)under a grant number of FRGS/1/2020/ICT09/UNIMAP/02/2.
文摘This article presents the generation of Orbital AngularMomentum(OAM)vortex waves with mode 1 using Uniform Circular Array(UCA)antenna.Two different designs,namely,UCA-1(4-element array antenna)and UCA-2(8-element array antenna),were designed and fabricated using FR-4 substrate to generate OAM mode 1 at 3.5 GHz(5G mid-band).The proposed antenna arrays comprised rectangular microstrip patch elements with inset fed technique.The elements were excited by a carefully designed feeding phase shift network to provide similar output energy at output ports with desired phase shift value.The generated OAM waves were confirmed by measuring the null in the bore sight of their 2D radiation patterns,simulated phase distribution and intensity distribution.The measurement results agree well with the simulation results.Moreover,a detailed mode purity analysis of the generated OAM waves was carried out considering different factors.The investigation found that the greater the number of elements,the higher the purity of the generated OAM wave.Compared with other previous works,the proposed antenna design of this paper is very simple to design and fabricate.In addition,the proposed antennas are compact in design even at lower frequency band with very wide bandwidth to meet the requirements of 5G mid-band applications.
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The programmable metasurface(PM)is an antenna array architecture that realizes flexible beam steering.This functionality is achieved by controlling the unit cells designed with micro components such as positive-intrinsic-negative(PIN)diodes,which offers potential cost reductions in the next generation wireless communication systems.Although PM has been a popular topic in antenna design,its implementations in real-time systems accompanied by signal processing algorithms are challenging.In this paper,novel predictive tracking algorithms for mobile communication scenarios using a PM are created and implemented in a real-time system operating at 28 GHz.An angular speed prediction(ASP)algorithm is proposed to compute the position of user equipment(UE)based on the previously recorded beam directions.As another solution,an angle correction(AC)algorithm is proposed to further improve the prediction and tracking accuracy.As a benchmark,the comparisons to a previous PM tracking algorithm without prediction are presented.Both simulation and measurement results show that the prediction algorithms successfully improve the tracking performance,which also prove the feasibilities of PM-based systems to solve complex real-time signal processing problems.
文摘5G is a new generation of mobile networking that aims to achieve unparalleled speed and performance. To accomplish this, three technologies, Device-to-Device communication (D2D), multi-access edge computing (MEC) and network function virtualization (NFV) with ClickOS, have been a significant part of 5G, and this paper mainly discusses them. D2D enables direct communication between devices without the relay of base station. In 5G, a two-tier cellular network composed of traditional cellular network system and D2D is an efficient method for realizing high-speed communication. MEC unloads work from end devices and clouds platforms to widespread nodes, and connects the nodes together with outside devices and third-party providers, in order to diminish the overloading effect on any device caused by enormous applications and improve users’ quality of experience (QoE). There is also a NFV method in order to fulfill the 5G requirements. In this part, an optimized virtual machine for middle-boxes named ClickOS is introduced, and it is evaluated in several aspects. Some middle boxes are being implemented in the ClickOS and proved to have outstanding performances.
文摘Objectives:The uses of devices of electromagnetic waves(EMWs)are increasing day by day.Similarly,the generation of the waves is increasing.The frequency spectrum of the generation of waves is also increased.In this manuscript,an analysis of the high frequency EMWs has been made by the electric fields generated due to the exposure of 5th generation(5 G)of mobile phones.Methods:Due to the emission of waves from the towers,the electric field is generated around the transmission tower of mobile phones.The electric fields are computed by the power of the transmission tower.The electric fields across the biological tissues/cells are also computed when the EMWs penetrate inside the body.The electric fields are made across the organs of different depths inside the body.Results:The induced electric fields inside the organs of the human beings are responsible for the absorption of energy from high frequency EMWs.The absorbed amount of energy from high frequency waves may become the cause of harmful effects on the life of organs of human beings.Conclusion:In this manuscript,after analysis of the computed electric fields inside the organs of human beings,it is concluded that the EMWs of 5 G spectrum of mobile phone towers may more harmful for the life of organs as 4th generation(4 G)spectrum of mobile phone waves.The energy absorption by the 4 G spectrum is lower than 5 G spectrum due to the range of frequency of waves.The effects on the pancreas,retina,skin,intestine,spleen,stomach and uterus are more than low water content organs like nails,bone,teeth etc.
文摘Based on the characteristics of the radio propagation in land mobile communications environment, a theoretical model for the reflecting(scattering) number of each radio path is derived firstly. This model can be used to predict the variation of radio path strength, which is important for practical mobile communications engineering. Using this model, a method for simulating radio path strength is developed, with numerical results presented.
文摘In the paper, we illustrate the importance of the concept of mobile network computer from a technological perspective. Because of the usefulness of mobile network computers, with the growth of the Internet of things, mobile network computers may include not only TV box audio-visual equipment, wireless household appliances, and mobile communication equipment, but may also include devices such as intelligent foot rings, smart watches, smart glasses, smart shoes and smart coats. Considering the different types of networks, e.g. IP multimedia Subsystem(IMS), we explain why some network elements are inaccurate and misleading from a technological perspective. We aim to popularize the concept of mobile network computers for its accuracy and importance, which better define modern mobile terminals and reflects the nature of multiple mobile terminals based on the structure of their integrated computers and the capabilities of processing multimedia. In the computer and Internet age, network computers and mobile network computers are the main terminals of fixed and mobile networks, respectively. Therefore, based on the concept of mobile network computers, we discuss the future of information society.
文摘Fifth Generation(5G)communications are regarded as the cornerstone to household consumer experience improvements and smart manufacturing revolution from the standpoint of industries’objectives.It is anticipated that Envisaged 5G(E5G)mobile technology would be operational in certain developed countries by 2023.The Internet of Things(IoTs)will transform how humans live when combined with smart and integrated sensing devices,such as in-home sensing devices.Recent research is being carried out all over the world to produce a new technique that can be crucial in the success of the anticipated 5G mobile technology.High output,reduced latency,highly reliable,greater scalability,high performance,capacity,bandwidth efficiency,virtual open-air transmission,and efficient energy mobile wireless communications are all being investigated currently.In this work,a comprehensive path for addressing the difficulties and developments associated with 5G mobile technology is provided.The debate and description of a complete analysis of current situations,certain characteristics and prospective scenarios,important technologies,problems and advances,and spectrum allocation of envisioned 5G mobile technologies are provided.Furthermore,this paper analyzes the most notable elements of 5G mobile technology,such as Cognitive Radio(CR),flexibility,accessibility,and cloud-based service offers,which will assure 5G mobile technology’s dominance as the main protocol for international communication.Eventually,this paper provides a method for integrating CR with current wireless communication systems,the necessity for further evolution of the E5G network,and the need for comprehensive consideration of architecture evolution and function enhancement to enhance the E5G mobile technologies.