In 5G networks,optimization of antenna beam weights of base stations has become the key application of AI for network optimization.For 6G,higher frequency bands and much denser cells are expected,and the importance of...In 5G networks,optimization of antenna beam weights of base stations has become the key application of AI for network optimization.For 6G,higher frequency bands and much denser cells are expected,and the importance of automatic and accurate beamforming assisted by AI will become more prominent.In existing network,servers are“patched”to network equipment to act as a centralized brain for model training and inference leading to high transmission overhead,large inference latency and potential risks of data security.Decentralized architectures have been proposed to achieve flexible parameter configuration and fast local response,but it is inefficient in collecting and sharing global information among base stations.In this paper,we propose a novel solution based on a collaborative cloud edge architecture for multi-cell joint beamforming optimization.We analyze the performance and costs of the proposed solution with two other architectural solutions by simulation.Compared with the centralized solution,our solution improves prediction accuracy by 24.66%,and reduces storage cost by 83.82%.Compared with the decentralized solution,our solution improves prediction accuracy by 68.26%,and improves coverage performance by 0.4 dB.At last,the future research work is prospected.展开更多
Cloud computing technology is the culmination of technical advancements in computer networks,hardware and software capabilities that collectively gave rise to computing as a utility.It offers a plethora of utilities t...Cloud computing technology is the culmination of technical advancements in computer networks,hardware and software capabilities that collectively gave rise to computing as a utility.It offers a plethora of utilities to its clients worldwide in a very cost-effective way and this feature is enticing users/companies to migrate their infrastructure to cloud platform.Swayed by its gigantic capacity and easy access clients are uploading replicated data on cloud resulting in an unnecessary crunch of storage in datacenters.Many data compression techniques came to rescue but none could serve the purpose for the capacity as large as a cloud,hence,researches were made to de-duplicate the data and harvest the space from exiting storage capacity which was going in vain due to duplicacy of data.For providing better cloud services through scalable provisioning of resources,interoperability has brought many Cloud Service Providers(CSPs)under one umbrella and termed it as Cloud Federation.Many policies have been devised for private and public cloud deployment models for searching/eradicating replicated copies using hashing techniques.Whereas the exploration for duplicate copies is not restricted to any one type of CSP but to a set of public or private CSPs contributing to the federation.It was found that even in advanced deduplication techniques for federated clouds,due to the different nature of CSPs,a single file is stored at private as well as public group in the same cloud federation which can be handled if an optimized deduplication strategy be rendered for addressing this issue.Therefore,this study has been aimed to further optimize a deduplication strategy for federated cloud environment and suggested a central management agent for the federation.It was perceived that work relevant to this is not existing,hence,in this paper,the concept of federation agent has been implemented and deduplication technique following file level has been used for the accomplishment of this approach.展开更多
Snow cover plays an important role in the fields of climatology and cryospheric science. Remotely-sensed data have been proven to be effective in monitoring snow covers. Improved methods to process the 8-day snow-cove...Snow cover plays an important role in the fields of climatology and cryospheric science. Remotely-sensed data have been proven to be effective in monitoring snow covers. Improved methods to process the 8-day snow-cover products derived from MODIS Terra/Aqua data can dramatically increase the data quality and reduce noise. A five-step algorithm for removing cloud effects was designed to improve the quality of MODIS snow products, and the overall accuracy of the MODIS snow data without cloud（defined as cloud-free snow-cover dataset） was enhanced by more than 90% based on direct and indirect validation methods. The snow-cover frequency（SCF） and snow-cover rate（SCR） of Central Asia were analyzed from 2000 to 2015 using trend analysis and empirical orthogonal functions（EOFs）. Over the plain regions, the SCF displayed a significant north-south declining trend with a rate of 0.03 per degree of latitude, and the SCR showed a similar north-south gradient. In the mountainous areas, the SCF significantly increased with altitude by 0.12 per kilometer. Within the study area, the SCF in 65% of the study area experienced an increasing trend, but only 4.3% of the SCF-increasing pixels passed a significance test. The remaining 35% of the area underwent a decreasing trend of SCF, but only 5.2% of the SCF-decreasing pixels passed a significance test. For the entire Central Asia, the inter-annual variations of snow-cover presented a slight and insignificant increase trend from 2000 to 2015. However, the change trends of snow cover are different between the plain and mountainous regions. That is, the annual mean SCR in the plain areas displayed an increasing trend, but a decreasing trend was found in the mountainous areas.展开更多
Based on the CINRAD Doppler radar data in Guangzhou and the lightning data in 2004 by power suppliers of Guangdong, statistical study is done by overlaying lightning’s position on radar’s echo. The result shows the ...Based on the CINRAD Doppler radar data in Guangzhou and the lightning data in 2004 by power suppliers of Guangdong, statistical study is done by overlaying lightning’s position on radar’s echo. The result shows the followings. The concentrated period in which more negative lightning occurred at the middle levels (2 – 14 km), where radar echo was moderate (12 – 45 dBz), rather than at the low levels with the weakest echoes or at high levels with the strongest echoes. At levels 3 – 11 km, where the radar echo was between 10 dBz and 35 dBz, the area of negative lightning was much larger in central Guangdong than in the rest of the province. At levels 0.5 – 7 km where the radar echoes were between 44 dBz and 51 dBz, the probability for a point to have negative lightning varies from 0.4 to 0.7.展开更多
随着信息通信技术的快速发展和广泛部署,人类的生产生活以及社会治理向数字化、信息化、智能化方向不断深入演进。作为应用最广泛的无线通信技术之一,无线局域网(WLAN,wireless local area network)需要在吞吐量、可靠性、时延等关键性...随着信息通信技术的快速发展和广泛部署,人类的生产生活以及社会治理向数字化、信息化、智能化方向不断深入演进。作为应用最广泛的无线通信技术之一,无线局域网(WLAN,wireless local area network)需要在吞吐量、可靠性、时延等关键性能上进一步突破,同时还需要具备感知、智能等新特性。毫米波(mmWave,millimeter wave)巨大的频率资源为无线局域网发展注入了新动能,但同时也带来了新的技术挑战和需求。首先,回顾了无线局域网的发展历程;其次,描述了未来无线局域网的网络结构、典型应用、发展方向和性能指标要求;然后,分析了毫米波频段无线信道特性及其对无线网络设计的新要求、新挑战;最后,对能够适应这些挑战和要求的一些潜在关键技术进行了探讨和展望。展开更多
近年来,随着我国经济不断发展,我国北方城市供热需求日趋增长。2021年以来,我国北方多地区迎来历史最强寒潮,但各地区冬季供热困难问题积存已久,导致资源浪费和环境污染问题层出不穷。目前,远程供热监控系统成为供热公司应对供热困难的...近年来,随着我国经济不断发展,我国北方城市供热需求日趋增长。2021年以来,我国北方多地区迎来历史最强寒潮,但各地区冬季供热困难问题积存已久,导致资源浪费和环境污染问题层出不穷。目前,远程供热监控系统成为供热公司应对供热困难的主要手段,但目前仍未有成熟的技术出现。基于中国电信天翼物联网云平台和窄带物联网技术(Narrow Band Internet of Things,NB-IoT)设计了一款集中供热阀门远程控制系统。分析了集中供热阀门远程控制系统的需求,搭建了基于“云-管-端”的系统主框架。完成了集中供热阀门远程控制系统的硬件终端构架并编写了下位机软件。应用天翼物联网云平台,实现了集中供热阀门远程控制系统的设备管理、数据储存、数据查看、远程控制等功能。通过对系统的测试,验证了设计的实用性。该设计完成了对用户单元阀门进水温度数据、开度数据实时采集上传的任务,实现了对单元阀门开度远程控制的任务,为我国冬季北方居民提供了更好的采暖服务。展开更多
基金supported by the National Key Research and Development Program of China(2020YFB1806800)funded by Beijing University of Posts and Telecommuns(BUPT)China Mobile Research Institute Joint Innoviation Center。
文摘In 5G networks,optimization of antenna beam weights of base stations has become the key application of AI for network optimization.For 6G,higher frequency bands and much denser cells are expected,and the importance of automatic and accurate beamforming assisted by AI will become more prominent.In existing network,servers are“patched”to network equipment to act as a centralized brain for model training and inference leading to high transmission overhead,large inference latency and potential risks of data security.Decentralized architectures have been proposed to achieve flexible parameter configuration and fast local response,but it is inefficient in collecting and sharing global information among base stations.In this paper,we propose a novel solution based on a collaborative cloud edge architecture for multi-cell joint beamforming optimization.We analyze the performance and costs of the proposed solution with two other architectural solutions by simulation.Compared with the centralized solution,our solution improves prediction accuracy by 24.66%,and reduces storage cost by 83.82%.Compared with the decentralized solution,our solution improves prediction accuracy by 68.26%,and improves coverage performance by 0.4 dB.At last,the future research work is prospected.
文摘Cloud computing technology is the culmination of technical advancements in computer networks,hardware and software capabilities that collectively gave rise to computing as a utility.It offers a plethora of utilities to its clients worldwide in a very cost-effective way and this feature is enticing users/companies to migrate their infrastructure to cloud platform.Swayed by its gigantic capacity and easy access clients are uploading replicated data on cloud resulting in an unnecessary crunch of storage in datacenters.Many data compression techniques came to rescue but none could serve the purpose for the capacity as large as a cloud,hence,researches were made to de-duplicate the data and harvest the space from exiting storage capacity which was going in vain due to duplicacy of data.For providing better cloud services through scalable provisioning of resources,interoperability has brought many Cloud Service Providers(CSPs)under one umbrella and termed it as Cloud Federation.Many policies have been devised for private and public cloud deployment models for searching/eradicating replicated copies using hashing techniques.Whereas the exploration for duplicate copies is not restricted to any one type of CSP but to a set of public or private CSPs contributing to the federation.It was found that even in advanced deduplication techniques for federated clouds,due to the different nature of CSPs,a single file is stored at private as well as public group in the same cloud federation which can be handled if an optimized deduplication strategy be rendered for addressing this issue.Therefore,this study has been aimed to further optimize a deduplication strategy for federated cloud environment and suggested a central management agent for the federation.It was perceived that work relevant to this is not existing,hence,in this paper,the concept of federation agent has been implemented and deduplication technique following file level has been used for the accomplishment of this approach.
基金funded by the National Key Research and Development Program of China (2016YFA0602302,2016YFB0502502)
文摘Snow cover plays an important role in the fields of climatology and cryospheric science. Remotely-sensed data have been proven to be effective in monitoring snow covers. Improved methods to process the 8-day snow-cover products derived from MODIS Terra/Aqua data can dramatically increase the data quality and reduce noise. A five-step algorithm for removing cloud effects was designed to improve the quality of MODIS snow products, and the overall accuracy of the MODIS snow data without cloud（defined as cloud-free snow-cover dataset） was enhanced by more than 90% based on direct and indirect validation methods. The snow-cover frequency（SCF） and snow-cover rate（SCR） of Central Asia were analyzed from 2000 to 2015 using trend analysis and empirical orthogonal functions（EOFs）. Over the plain regions, the SCF displayed a significant north-south declining trend with a rate of 0.03 per degree of latitude, and the SCR showed a similar north-south gradient. In the mountainous areas, the SCF significantly increased with altitude by 0.12 per kilometer. Within the study area, the SCF in 65% of the study area experienced an increasing trend, but only 4.3% of the SCF-increasing pixels passed a significance test. The remaining 35% of the area underwent a decreasing trend of SCF, but only 5.2% of the SCF-decreasing pixels passed a significance test. For the entire Central Asia, the inter-annual variations of snow-cover presented a slight and insignificant increase trend from 2000 to 2015. However, the change trends of snow cover are different between the plain and mountainous regions. That is, the annual mean SCR in the plain areas displayed an increasing trend, but a decreasing trend was found in the mountainous areas.
文摘Based on the CINRAD Doppler radar data in Guangzhou and the lightning data in 2004 by power suppliers of Guangdong, statistical study is done by overlaying lightning’s position on radar’s echo. The result shows the followings. The concentrated period in which more negative lightning occurred at the middle levels (2 – 14 km), where radar echo was moderate (12 – 45 dBz), rather than at the low levels with the weakest echoes or at high levels with the strongest echoes. At levels 3 – 11 km, where the radar echo was between 10 dBz and 35 dBz, the area of negative lightning was much larger in central Guangdong than in the rest of the province. At levels 0.5 – 7 km where the radar echoes were between 44 dBz and 51 dBz, the probability for a point to have negative lightning varies from 0.4 to 0.7.
文摘随着信息通信技术的快速发展和广泛部署,人类的生产生活以及社会治理向数字化、信息化、智能化方向不断深入演进。作为应用最广泛的无线通信技术之一,无线局域网(WLAN,wireless local area network)需要在吞吐量、可靠性、时延等关键性能上进一步突破,同时还需要具备感知、智能等新特性。毫米波(mmWave,millimeter wave)巨大的频率资源为无线局域网发展注入了新动能,但同时也带来了新的技术挑战和需求。首先,回顾了无线局域网的发展历程;其次,描述了未来无线局域网的网络结构、典型应用、发展方向和性能指标要求;然后,分析了毫米波频段无线信道特性及其对无线网络设计的新要求、新挑战;最后,对能够适应这些挑战和要求的一些潜在关键技术进行了探讨和展望。
文摘近年来,随着我国经济不断发展,我国北方城市供热需求日趋增长。2021年以来,我国北方多地区迎来历史最强寒潮,但各地区冬季供热困难问题积存已久,导致资源浪费和环境污染问题层出不穷。目前,远程供热监控系统成为供热公司应对供热困难的主要手段,但目前仍未有成熟的技术出现。基于中国电信天翼物联网云平台和窄带物联网技术(Narrow Band Internet of Things,NB-IoT)设计了一款集中供热阀门远程控制系统。分析了集中供热阀门远程控制系统的需求,搭建了基于“云-管-端”的系统主框架。完成了集中供热阀门远程控制系统的硬件终端构架并编写了下位机软件。应用天翼物联网云平台,实现了集中供热阀门远程控制系统的设备管理、数据储存、数据查看、远程控制等功能。通过对系统的测试,验证了设计的实用性。该设计完成了对用户单元阀门进水温度数据、开度数据实时采集上传的任务,实现了对单元阀门开度远程控制的任务,为我国冬季北方居民提供了更好的采暖服务。
