The planning of wireless communication networks in underdeveloped countries is studied for landline telephone, fixed broadband wireless access and PLMN systems via investigation and discussion of the LDC networks＇ ch...The planning of wireless communication networks in underdeveloped countries is studied for landline telephone, fixed broadband wireless access and PLMN systems via investigation and discussion of the LDC networks＇ characteristic, technology selection, deployment consideration, network configuring, civil work evaluation and investment estimation. An example is embedded all through providing a general展开更多
McWiLL(multi-carrier wireless information local loop,多载波无线信息本地环路)是集智能天线、CS-OFDMA、增强零陷、信道跟踪和预测、动态信道分配、频空联合检测等核心技术为一体的宽带无线通信系统。为此,介绍了McWiLL系统在配电...McWiLL(multi-carrier wireless information local loop,多载波无线信息本地环路)是集智能天线、CS-OFDMA、增强零陷、信道跟踪和预测、动态信道分配、频空联合检测等核心技术为一体的宽带无线通信系统。为此,介绍了McWiLL系统在配电网通信中应用的测试情况,重点在于McWiLL系统的覆盖面、业务容量和业务承载能力。基于中低压配电网的特点及其对通信的需求,提出了在中低压配电网中McWiLL的应用模型。展开更多
为了增强煤矿井下安全生产、抢险救灾的能力和提高管理效率,基于数字矿山综合无线局域网络系统设计了煤矿井下无线导航系统。通过利用井下接入点设备(Access Point,AP)的基本服务集识别码和导航设备接收到的信号强度指示进行导航系统内...为了增强煤矿井下安全生产、抢险救灾的能力和提高管理效率,基于数字矿山综合无线局域网络系统设计了煤矿井下无线导航系统。通过利用井下接入点设备(Access Point,AP)的基本服务集识别码和导航设备接收到的信号强度指示进行导航系统内人员与设备的定位。利用嵌入式地理信息系统eSuperMap开发平台和WinCE嵌入式操作系统,在定位的基础上实现对煤矿井下作业人员和流动设备的导航。开发了电子地图操作、信息查询、路径分析、导航等功能,并在Pocket PC 2003模拟器上进行了模拟演示,表明了该系统的可行性。这些工作为煤矿井下无线导航系统的进一步开发打下了重要技术基础。展开更多
This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocatio...This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocation at 45 GHz band is introduced. Next, the channel measurement and mod-eling is given. Specifically, the millimeter-wave MIMO for physical layer enhancement is given in detail.展开更多
Wireless Network rapid development and use present more high security request for constantly extensivenetwork system. By analyzing existing wireless LAN safety measure at this paper proposes and realizes overall infor...Wireless Network rapid development and use present more high security request for constantly extensivenetwork system. By analyzing existing wireless LAN safety measure at this paper proposes and realizes overall infor-mation safe protection solution ,strengthens the security of the communication data in the wireless LAN greatly.展开更多
为估算网络的性能,研究了无线LAN(Local Area Network)网络的媒体接入控制协议,提出一种无线LAN网络的模型设计方案。在网络模型扩展的情况下,通过仿真实验验证了,无线LAN网络在最大服务器负载和网络收敛时的延时具有良好的性能。实验...为估算网络的性能,研究了无线LAN(Local Area Network)网络的媒体接入控制协议,提出一种无线LAN网络的模型设计方案。在网络模型扩展的情况下,通过仿真实验验证了,无线LAN网络在最大服务器负载和网络收敛时的延时具有良好的性能。实验运行结果表明,该方案在不增大网络成本的情况下,网络收敛延时为0.4μs,其性能并没有因为服务器负载的增加而受到影响,从而验证了模型和结论的合理性。展开更多
因用户的游移和喜好集会活动,用户在无线局域网(wireless local area network,WLAN)中的分布是非常不均匀的且是动态变化的.当1个WLAN的用户数量很大时,整个网络和每个用户的吞吐量都会大幅下降.对于1个WLAN范围内的间歇拥塞问题,已有...因用户的游移和喜好集会活动,用户在无线局域网(wireless local area network,WLAN)中的分布是非常不均匀的且是动态变化的.当1个WLAN的用户数量很大时,整个网络和每个用户的吞吐量都会大幅下降.对于1个WLAN范围内的间歇拥塞问题,已有的性能改进方法存在一些不足.因此,提出了1套WLAN动态切分与重构的方案SRD(splitting and restructuring dynamically),引入了影子AP(shadow access point,SAP)和终端映射2个概念,并对终端映射和方案的整体性能进行了形式化分析,设计了最优映射的计算方法.该方案能根据网络负载及状态的变化,动态地将1个拥挤的WLAN切分成若干子网,并重构成1个微型的集中式架构的WLAN,从而对各子网中的终端分布进行监控.因此,该方案能大幅减少1个子网中的终端数量,提高用户吞吐量,缓解冲突和异构速率的影响.仿真结果表明,该方案能成倍地提高网络及每个用户的吞吐量,此外,该方案的部署不需要用户终端设备作任何的更改.展开更多
文摘The planning of wireless communication networks in underdeveloped countries is studied for landline telephone, fixed broadband wireless access and PLMN systems via investigation and discussion of the LDC networks＇ characteristic, technology selection, deployment consideration, network configuring, civil work evaluation and investment estimation. An example is embedded all through providing a general
文摘McWiLL(multi-carrier wireless information local loop,多载波无线信息本地环路)是集智能天线、CS-OFDMA、增强零陷、信道跟踪和预测、动态信道分配、频空联合检测等核心技术为一体的宽带无线通信系统。为此,介绍了McWiLL系统在配电网通信中应用的测试情况,重点在于McWiLL系统的覆盖面、业务容量和业务承载能力。基于中低压配电网的特点及其对通信的需求,提出了在中低压配电网中McWiLL的应用模型。
文摘为了增强煤矿井下安全生产、抢险救灾的能力和提高管理效率,基于数字矿山综合无线局域网络系统设计了煤矿井下无线导航系统。通过利用井下接入点设备(Access Point,AP)的基本服务集识别码和导航设备接收到的信号强度指示进行导航系统内人员与设备的定位。利用嵌入式地理信息系统eSuperMap开发平台和WinCE嵌入式操作系统,在定位的基础上实现对煤矿井下作业人员和流动设备的导航。开发了电子地图操作、信息查询、路径分析、导航等功能,并在Pocket PC 2003模拟器上进行了模拟演示,表明了该系统的可行性。这些工作为煤矿井下无线导航系统的进一步开发打下了重要技术基础。
基金supported in part by National Key Basic Research Program of China (973 Program) under Grant No. 2013CB329002National Natural Science Foundation of China under Grant No. 61132003the Natural Science Foundation of Jiangsu Province of China under Grants BK2011019 and BK20130631
文摘This paper presents an overview of a new very high throughput millimeterwave WLAN system operating at 45 GHz band. We begin by reviewing standards process of IEEE 802.11aj(45GHz). Then the frequency spectrum allocation at 45 GHz band is introduced. Next, the channel measurement and mod-eling is given. Specifically, the millimeter-wave MIMO for physical layer enhancement is given in detail.
文摘Wireless Network rapid development and use present more high security request for constantly extensivenetwork system. By analyzing existing wireless LAN safety measure at this paper proposes and realizes overall infor-mation safe protection solution ,strengthens the security of the communication data in the wireless LAN greatly.
文摘为估算网络的性能,研究了无线LAN(Local Area Network)网络的媒体接入控制协议,提出一种无线LAN网络的模型设计方案。在网络模型扩展的情况下,通过仿真实验验证了,无线LAN网络在最大服务器负载和网络收敛时的延时具有良好的性能。实验运行结果表明,该方案在不增大网络成本的情况下,网络收敛延时为0.4μs,其性能并没有因为服务器负载的增加而受到影响,从而验证了模型和结论的合理性。
文摘因用户的游移和喜好集会活动,用户在无线局域网(wireless local area network,WLAN)中的分布是非常不均匀的且是动态变化的.当1个WLAN的用户数量很大时,整个网络和每个用户的吞吐量都会大幅下降.对于1个WLAN范围内的间歇拥塞问题,已有的性能改进方法存在一些不足.因此,提出了1套WLAN动态切分与重构的方案SRD(splitting and restructuring dynamically),引入了影子AP(shadow access point,SAP)和终端映射2个概念,并对终端映射和方案的整体性能进行了形式化分析,设计了最优映射的计算方法.该方案能根据网络负载及状态的变化,动态地将1个拥挤的WLAN切分成若干子网,并重构成1个微型的集中式架构的WLAN,从而对各子网中的终端分布进行监控.因此,该方案能大幅减少1个子网中的终端数量,提高用户吞吐量,缓解冲突和异构速率的影响.仿真结果表明,该方案能成倍地提高网络及每个用户的吞吐量,此外,该方案的部署不需要用户终端设备作任何的更改.
