DMAP: integrated mobility and service management in mobile IPv6 systems

Mobile IPv6 (MIPv6) is a work in progress IETF standard for enabling mobility in IPv6 networks and is expected to have wide deployment. We investigate an integrated mobility and service management scheme based on MIPv6 with the goal to minimize the overall network signaling cost in MIPv6 systems for serving mobility and service management related operations. Our design extends IETF work-in-progress Hierarchical Mobile IPv6 (HMIPv6) with the notion of dynamic mobility anchor points (DMAPs) for each mobile node (MN) instead of static ones for all MNs. These DMAPs are access routers chosen by individual MNs to act as a regional router to reduce the signaling overhead for intra-regional movements. The DMAP domain size, i.e., the number of subnets covered by a DMAP, is based on the MN’s mobility and service characteristics. Under our DMAP protocol, a MN interacts with its home agent and application servers as in the MIPv6 protocol, but optimally determines when and where to launch a DMAP to minimize the network cost in serving the user’s mobility and service management operations. We demonstrate that our DMAP protocol for integrated mobility and service management yields significantly improved performance over basic MIPv6 and HMIPv6.     

Ultra-Thin Si<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> Dislocation Blocking Layers for Ge/Strained Si CMOS Devices

We demonstrate ultra-thin (<150 nm) Si_1−x Ge _x dislocation blocking layers on Si substrates used for the fabrication of tensile-strained Si N channel metal oxide semiconductor (NMOS) and Ge P channel metal oxide semiconductor (PMOS) devices. These layers were grown using ultra high vacuum chemical vapor deposition (UHVCVD). The Ge mole fraction was varied in rapid, but distinct steps during the epitaxial layer growth. This results in several Si_1−x Ge _x interfaces in the epitaxially grown material with significant strain fields at these interfaces. The strain fields enable a dislocation blocking mechanism at the Si_1−x Ge _x interfaces on which we were able to deposit very smooth, atomically flat, tensile-strained Si and relaxed Ge layers for the fabrication of high mobility N and P channel metal oxide semiconductor (MOS) devices, respectively. Both N and P channel metal oxide semiconductor field effect transister (MOSFETs) were successfully fabricated using high-k dielectric and metal gates on these layers, demonstrating that this technique of using ultra-thin dislocation blocking layers might be ideal for incorporating high mobility channel materials in a conventional CMOS process.     

EPON的调和子层和CRC-8的VHDL语言程序实现

文中介绍了EPON的调和子层。对调和子层与OSI参考模型的关系进行了简要的介绍，重点讨论了调和子层的工作原理、CRC-8的算法分析、CRC-8的VHDL语言程序实现。     

用于产生微波信号的分布反馈激光器与Y形波导单片集成器件的研究

设计并制作了一种在Y形波导的两个分支上集成分布反馈(distributed feedback,DFB)激光器的单片集成器件.DFB激光器的布拉格光栅一次曝光形成,具有相同的光栅周期.当注入电流分别单独加载到两段DFB激光器之上时,从Y形波导端输出光波长在1565nm附近,边模抑制比大于30dB.当大于阈值且相差大于20mA的两个电流同时加载到两段DFB激光器上时,从Y形波导端输出的光谱具有双模分布,双模频率的差值可以拍频产生微波频段的信号.通过调节两段DFB的注入电流,微波信号的频率可以在13～42GHz之间快速连续调谐.这种基于Y形波导的两段DFB并联的拍频光源比传统的双段级联DFB器件有较好的光学和电学隔离,可以作为光学拍频源的一种新的实现方法.     

高温超导滤波器子系统的进展

高温超滤波器基站子系统是高温超导微波器件在移动通信领域中的重要应用,在增加容量、增加覆盖、提高频谱利用率、降低干扰、减小手机发射功率,给用户带来降低接入失败率、减小掉话率、延长通话时间,给运营商带来减小投资、提高服务质量等方面表现出优异的性能,引起了运营商的极大兴趣和热情。对高温超导滤波器基站子系统在国内外的发展和试验情况,以及将来的发展趋势进行总结,以便了解该技术的进展情况。     

EFFICIENT CYCLIC PREFIX RECONSTRUCTION USING DECISION FEEDBACK FILTER FOR CODED SINGLE-CARRIER SYSTEMS WITH FREQUENCY-DOMAIN EQUALIZATION （SC-FDE）

In this paper, an efficient Cyclic Prefix （CP） reconstruction scheme is proposed for Single-Carrier systems with Frequency-Domain Equalization （SC-FDE） that employ insufficient length of CP at the transmitter. By utilizing a decision feedback filter to cancel the residual InterSymbol Interference （ISI） in the equalized signal, the proposed scheme can effectively lower the low bound of performance for the CP reconstruction schemes and can greatly improve the Bit Error P~te （BER） performance of SC-FDE systems. In addition, the existing methods and the proposed scheme are also optimized. It is shown in the simulation results that, when the Signal-to-Noise Ratio （SNR） exceeds a certain threshold, the proposed scheme can achieve the low bound of performance for the existing methods. Moreover, by increasing the number of iteration or through optimization, the low bound can be outperformed.     

A novel iterative scheme for parallel inter-symbol interference channels

In this paper, we propose a novel iterative scheme for exploiting transmit diversity using parallel independent Inter-Symbol Interference （ISI） channels. In this adaptive iterative scheme, we use EXtrinsic Information Transfer （EXIT） chart tool to choose appropriate iterative method from Iterative Combining （IC）, used as parallel concatenation turbo-like scheme, and Turbo Equalization （TE）, used as serial concatenation turbo-like scheme. It is show that the proposed iterative scheme provides excellent performance both analytically and through simulations without any compute complexity increase comparable to IC.     

Power-aware routing based on DSR for Mobile Ad hoc NETworks

Energy consumption is a crucial design concern in Mobile Ad hoc NETworks （MANETs） since nodes are powered by batteries with limited energy, whereas Dynamic Source Routing （DSR） protocol does not take the energy limitation of MANET nodes into account. This paper proposes an energy-saving routing algorithm based on DSR： Power Aware Routing protocol based on DSR （PAR-DSR）. The design objective of PAR-DSR is to select energy-efficient paths. The main features of PAR-DSR are： （1） Nodes use the Signal Attenuation Rate （SAR） to conduct power control operations; （2） Minimum path cost as metric to balance the traffic and energy consumption of wireless nodes. The simulation results show that PAR-DSR can greatly reduce the energy consumption of MANET nodes. The average node lifetime of PAR-DSR is 50%-77% longer than that of DSR.     

Optimal wavelet filter design for remote sensing image compression

A new approach for designing the Biorthogonal Wavelet Filter Bank （BWFB） for the purpose of image compression is presented in this letter. The approach is decomposed into two steps. First, an optimal filter bank is designed in theoretical sense based on Vaidyanathan＇s coding gain criterion in SubBand Coding （SBC） system. Then the above filter bank is optimized based on the criterion of Peak Signal-to-Noise Ratio （PSNR） in JPEG2000 image compression system, resulting in a BWFB in practical application sense. With the approach, a series of BWFB for a specific class of applications related to image compression, such as remote sensing images, can be fast designed. Here, new 5/3 BWFB and 9/7 BWFB are presented based on the above approach for the remote sensing image compression applications. Experiments show that the two filter banks are equally performed with respect to CDF 9/7 and LT 5/3 filter in JPEG2000 standard; at the same time, the coefficients and the lifting parameters of the lifting scheme are all rational, which bring the computational advantage, and the ease for VLSI implementation.     

物联网应用实践及信息通信技术

介绍了物联网技术的基本概念,分析了应用方案原理以及实践案例,探讨物联网应用方案中的信息通信技术及其特点,最后阐述了信息通信技术在物联网中综合应用的价值。