为解决重大自然灾害发生后灾区电力系统的应急通信问题,近年来出现了利用Wi-Fi结合北斗技术的解决方案.如何增大系统覆盖能力、数据传输能力、用户承载能力,增强系统部署便宜性、灵活性是该应急通信系统面临的核心挑战.针对灾后电力应...为解决重大自然灾害发生后灾区电力系统的应急通信问题,近年来出现了利用Wi-Fi结合北斗技术的解决方案.如何增大系统覆盖能力、数据传输能力、用户承载能力,增强系统部署便宜性、灵活性是该应急通信系统面临的核心挑战.针对灾后电力应急通信系统上述核心需求,本研究基于第7代Wi-Fi多接入点(access point, AP)协作通信技术,提出一种协作式功率控制技术:增加无线接入过程中用户类型,并调整部分协议帧结构,具化相关字段用于指示新增用户类型;结合软频率复用技术设计了频谱资源分配算法和AP中心功率控制算法.仿真结果表明,与现有Wi-Fi系统多AP协作技术和软频率复用技术相比,所提算法有效提高了数据传输能力;与现有多AP协作技术相比,在用户承载能力相近条件下,可提高信号覆盖范围.展开更多
手持设备在工业和移动产品领域得到广泛应用并使得ARM处理器与WindowsCE操作系统紧密耦合。采用ADOCE作为WindowsCE操作系统下访问数据库提供的策略性高级接口,由OLEDB数据接口实现SQL Server CE的快速数据访问,而利用远程数据访问(RDA...手持设备在工业和移动产品领域得到广泛应用并使得ARM处理器与WindowsCE操作系统紧密耦合。采用ADOCE作为WindowsCE操作系统下访问数据库提供的策略性高级接口,由OLEDB数据接口实现SQL Server CE的快速数据访问,而利用远程数据访问(RDA)和无线局域网(Wi-Fi)技术支持手持移动设备与SQL Server服务器之间无线数据同步功能。通过综合分析并结合各自特点,在ARM-WinCE5.0平台上成功实现无线商品快速定位系统,并验证了其可操作性和有效性,产生了良好的经济效益。展开更多
Wireless communications have become an integral part of global convergence as global connectedness has gradually become dependent on its efficient deployment.The need for"more-broadband"techniques in relatio...Wireless communications have become an integral part of global convergence as global connectedness has gradually become dependent on its efficient deployment.The need for"more-broadband"techniques in relation to the ever increasing growth rate of the data hungry society now necessitates novel techniques for the high-speed data transmission.While advancements have been made in this regard,the projection of having an eventual Internet of everything (IoE) deployment will result in an unimaginable transmission data rate requirement as huge data traffic will be conveyed per time within the communications network,which will require a capacity upgrade of the existing infrastructure.Visible light communications (VLCs),as an integral part of optical wireless communications (OWCs),have been reviewed in this article,having the capacity to extend the achievable data rate requirement of the wireless communications network.The technologies,techniques,and best practices have been presented alongside technology integration for the seamless high capacity wireless broadband deployment.展开更多
文摘为解决重大自然灾害发生后灾区电力系统的应急通信问题,近年来出现了利用Wi-Fi结合北斗技术的解决方案.如何增大系统覆盖能力、数据传输能力、用户承载能力,增强系统部署便宜性、灵活性是该应急通信系统面临的核心挑战.针对灾后电力应急通信系统上述核心需求,本研究基于第7代Wi-Fi多接入点(access point, AP)协作通信技术,提出一种协作式功率控制技术:增加无线接入过程中用户类型,并调整部分协议帧结构,具化相关字段用于指示新增用户类型;结合软频率复用技术设计了频谱资源分配算法和AP中心功率控制算法.仿真结果表明,与现有Wi-Fi系统多AP协作技术和软频率复用技术相比,所提算法有效提高了数据传输能力;与现有多AP协作技术相比,在用户承载能力相近条件下,可提高信号覆盖范围.
文摘手持设备在工业和移动产品领域得到广泛应用并使得ARM处理器与WindowsCE操作系统紧密耦合。采用ADOCE作为WindowsCE操作系统下访问数据库提供的策略性高级接口,由OLEDB数据接口实现SQL Server CE的快速数据访问,而利用远程数据访问(RDA)和无线局域网(Wi-Fi)技术支持手持移动设备与SQL Server服务器之间无线数据同步功能。通过综合分析并结合各自特点,在ARM-WinCE5.0平台上成功实现无线商品快速定位系统,并验证了其可操作性和有效性,产生了良好的经济效益。
基金supported by the Petroleum Technology Development Fund under the Grant No. P4567720076521527。
文摘Wireless communications have become an integral part of global convergence as global connectedness has gradually become dependent on its efficient deployment.The need for"more-broadband"techniques in relation to the ever increasing growth rate of the data hungry society now necessitates novel techniques for the high-speed data transmission.While advancements have been made in this regard,the projection of having an eventual Internet of everything (IoE) deployment will result in an unimaginable transmission data rate requirement as huge data traffic will be conveyed per time within the communications network,which will require a capacity upgrade of the existing infrastructure.Visible light communications (VLCs),as an integral part of optical wireless communications (OWCs),have been reviewed in this article,having the capacity to extend the achievable data rate requirement of the wireless communications network.The technologies,techniques,and best practices have been presented alongside technology integration for the seamless high capacity wireless broadband deployment.
