To efficiently meet the increasing demands for mobile broadband, Ultra Mobile Broadband (UMB) is designed to complement 3G deployments. It is equipped with all the necessary features for optimal support of real-time a...To efficiently meet the increasing demands for mobile broadband, Ultra Mobile Broadband (UMB) is designed to complement 3G deployments. It is equipped with all the necessary features for optimal support of real-time and best-effort traffic with seamless mobility. This article overviews the UMB technology, and discusses its competitive advantages, which are fast time to market, flexible deployment options, inherently designed for real-time services and flexible IP-based network architecture. Moreover, the article analyzes key UMB design features, including Orthogonal Frequency Division Multiple Access (OFDMA), advanced antenna techniques, Reverse Link (RL) sector capacity optimization, adaptive interference management mechanisms, efficient RL control design, low-overhead signaling, fast seamless handoffs, multi-carrier support and beacons, enhanced terminal battery life, and flexible IP-based network architecture. UMB is well suited to be at the center of the future that melds broadband applications with faster, more capable mobile multimedia devices. UMB’s competitive advantages provide operators with continuous differentiation today and tomorrow.展开更多
The mobile multicast technology has been a research hotspot in the wireless Internet field in recent years.Quite a large part of its applications requires the reliability in a mobile environment to be equivalent to th...The mobile multicast technology has been a research hotspot in the wireless Internet field in recent years.Quite a large part of its applications requires the reliability in a mobile environment to be equivalent to that provided by wireline links.However,the inherent features of a mobile environment,that is,high error rate of links and dynamically changing multicast members’ locations,are great difficulties for mobile multicast,let alone reliable mobile multicast.The IPv4-based reliable mobile multicast algorithms come with two different design philosophies.A part of the algorithms is to be improved for better reliability by solving existing algorithm-related problems;while other algorithms are to implement reliable mobile multicast with new function entities introduced to guarantee reliability.展开更多
The fast development of IP services forces the traffic flow in the networks to move gradually from Time Division Multiplexing(TDM) services to packet data services.To adapt to the change,low-cost Ethernet technologies...The fast development of IP services forces the traffic flow in the networks to move gradually from Time Division Multiplexing(TDM) services to packet data services.To adapt to the change,low-cost Ethernet technologies are introduced into the Metropolitan Area Network(MAN).Ring network control protocols and ring network protection technologies are applied to guarantee manageability and reliability required in the telecom networks.The Ethernet Ring Protection(ERP) and Resilient Packet Ring(RPR) are two different ring protection technologies.The Transport Multi-Protocol Label Switching(T-MPLS) network uses the T-MPLS Shared Protection Ring(TM-SPRing) technology to provide ring protection.Carriers can expand the protection as needed and use appropriate ring technologies to meet the requirements of Carrier Ethernet(CE).展开更多
X连锁高IgM综合征(X-linked hyper-immunoglobulin M syndrome,XHIGM)是罕见的原发性免疫缺陷病,该病以反复感染为特征,易感染机会致病微生物。临床上以马尔尼菲篮状菌肺炎起病的XHIGM更为罕见。该文回顾性分析1例以马尔尼菲篮状菌肺炎...X连锁高IgM综合征(X-linked hyper-immunoglobulin M syndrome,XHIGM)是罕见的原发性免疫缺陷病,该病以反复感染为特征,易感染机会致病微生物。临床上以马尔尼菲篮状菌肺炎起病的XHIGM更为罕见。该文回顾性分析1例以马尔尼菲篮状菌肺炎起病的X连锁高IgM综合征婴儿的临床资料,实验室、影像学检查结果和诊疗经过并探讨其基因型,结合最新文献复习,以提高对该疾病的认识。展开更多
介绍了一种基于AC-link技术的并联谐振高压电源的拓扑电路,该结构结合准谐振的工作模式能够实现高功率因数和高效率;采用了基于状态平面图对并联谐振电路的分析方法,该方法相比传统的基波等效分析法具有求解简单、直观、精确和负载适用...介绍了一种基于AC-link技术的并联谐振高压电源的拓扑电路,该结构结合准谐振的工作模式能够实现高功率因数和高效率;采用了基于状态平面图对并联谐振电路的分析方法,该方法相比传统的基波等效分析法具有求解简单、直观、精确和负载适用范围大的特点,并给出了相应推导过程;给出了输出电压为25 k V,电流为1 A的变换器的分析和谐振参数设计。最后进行了仿真,仿真结果表明,基于高频交流链接并联谐振拓扑和基于状态平面图法的控制能够稳定输出电压(<1%),实现零电流开关,三相输入电流谐波较低(THD<12.5%)与三相电压基本同相位,功率因数为0.99。展开更多
文摘To efficiently meet the increasing demands for mobile broadband, Ultra Mobile Broadband (UMB) is designed to complement 3G deployments. It is equipped with all the necessary features for optimal support of real-time and best-effort traffic with seamless mobility. This article overviews the UMB technology, and discusses its competitive advantages, which are fast time to market, flexible deployment options, inherently designed for real-time services and flexible IP-based network architecture. Moreover, the article analyzes key UMB design features, including Orthogonal Frequency Division Multiple Access (OFDMA), advanced antenna techniques, Reverse Link (RL) sector capacity optimization, adaptive interference management mechanisms, efficient RL control design, low-overhead signaling, fast seamless handoffs, multi-carrier support and beacons, enhanced terminal battery life, and flexible IP-based network architecture. UMB is well suited to be at the center of the future that melds broadband applications with faster, more capable mobile multimedia devices. UMB’s competitive advantages provide operators with continuous differentiation today and tomorrow.
基金supported by the National High Technology Research and Development Program ("863" Program) under Grant No.2007AA10Z235
文摘The mobile multicast technology has been a research hotspot in the wireless Internet field in recent years.Quite a large part of its applications requires the reliability in a mobile environment to be equivalent to that provided by wireline links.However,the inherent features of a mobile environment,that is,high error rate of links and dynamically changing multicast members’ locations,are great difficulties for mobile multicast,let alone reliable mobile multicast.The IPv4-based reliable mobile multicast algorithms come with two different design philosophies.A part of the algorithms is to be improved for better reliability by solving existing algorithm-related problems;while other algorithms are to implement reliable mobile multicast with new function entities introduced to guarantee reliability.
基金supported by the National High-Tech Research and Development Plan of China ("863" Program) under Grant No.2006AA01Z246.
文摘The fast development of IP services forces the traffic flow in the networks to move gradually from Time Division Multiplexing(TDM) services to packet data services.To adapt to the change,low-cost Ethernet technologies are introduced into the Metropolitan Area Network(MAN).Ring network control protocols and ring network protection technologies are applied to guarantee manageability and reliability required in the telecom networks.The Ethernet Ring Protection(ERP) and Resilient Packet Ring(RPR) are two different ring protection technologies.The Transport Multi-Protocol Label Switching(T-MPLS) network uses the T-MPLS Shared Protection Ring(TM-SPRing) technology to provide ring protection.Carriers can expand the protection as needed and use appropriate ring technologies to meet the requirements of Carrier Ethernet(CE).
文摘X连锁高IgM综合征(X-linked hyper-immunoglobulin M syndrome,XHIGM)是罕见的原发性免疫缺陷病,该病以反复感染为特征,易感染机会致病微生物。临床上以马尔尼菲篮状菌肺炎起病的XHIGM更为罕见。该文回顾性分析1例以马尔尼菲篮状菌肺炎起病的X连锁高IgM综合征婴儿的临床资料,实验室、影像学检查结果和诊疗经过并探讨其基因型,结合最新文献复习,以提高对该疾病的认识。
文摘介绍了一种基于AC-link技术的并联谐振高压电源的拓扑电路,该结构结合准谐振的工作模式能够实现高功率因数和高效率;采用了基于状态平面图对并联谐振电路的分析方法,该方法相比传统的基波等效分析法具有求解简单、直观、精确和负载适用范围大的特点,并给出了相应推导过程;给出了输出电压为25 k V,电流为1 A的变换器的分析和谐振参数设计。最后进行了仿真,仿真结果表明,基于高频交流链接并联谐振拓扑和基于状态平面图法的控制能够稳定输出电压(<1%),实现零电流开关,三相输入电流谐波较低(THD<12.5%)与三相电压基本同相位,功率因数为0.99。
