Data transport applications using GFP

An emerging generic framing procedure (GFP) standard defines a new data encapsulation protocol designed to accept and transport multiple protocols over metropolitan, storage, and wide area networks. Why is another data encapsulation method needed for transporting data traffic over WANs? How does GFP encapsulate data for transport? This article provides an introduction to data transport applications, reviews existing data transport options (e.g., ATM and HDLC), introduces GFP as a new data transport technology, and compares GFP transport to existing popular alternatives     

Generic framing procedure (GFP): the catalyst for efficient dataover transport

We discuss the generic framing procedure (GFP) in the context of emerging nontraditional data over transport applications. Coupled with complementary efforts to define virtual concatenation, automatic link capacity adjustment schemes, and distributed control planes for transport networks, we contend that GFP serves as the catalyst for efficient and standard data over transport service offerings     

通用成帧规程GFP协议结构特点及其关键技术

通用成帧规程GFP(Generic Framing Procedure)是光同步数字传输网SDH上的新型数据包传输协议,简化了Data over SDH体系,可以支持各类高层客户信号。作为新一代面向无连接的数据链路层协议,详细介绍了该协议的特点、帧结构和功能实现方式。特别分析了GFP的通用处理过程和特定净荷处理过程。指出GFP作为新一代基于SDH的多业务传送平台MSPP的核心技术之一,将在现有的网络中得到广泛的应用和发展。     

新一代MSTP的关键技术和发展方向

目前,基于同步数字体系(SDH)的多业务传送平台(MSTP)在国内已成为城域汇聚层和接入层的主流技术。为了进一步增强数据处理能力,更好地与数据网络结合,新技术和新功能层出不穷。随着通用成帧规程(GFP)、虚级联(VCat)、链路容量调整(LCAS)、弹性分组环(RPR)、多协议标签交换(MPLS)、自动交换光网络(ASON)等技术国际标准的相继推出,新一代MSTP设备将逐步采用这些核心技术,面对新时期城域网IP业务大量兴起,MSTP逐步从简单透传、汇聚、共享发展到带宽管理,具备面向数据优化的传送能力。文中对新一代MSTP的关键技术进行讨论,着重分析这些新技术在MSTP中的功能和应用,并探讨新一代MSTP的发展方向。     

通用成帧规程GFP的原理和应用

ITU-TG.7041通用成帧规程(GFP)是一种简便的可将高层客户数据信号适配到位/字节同步物理传输信道的通用方法,它能简化传输过程的映射处理,并有效地提高传输效率。文章介绍GFP的产生背景、帧格式和通用成帧原理及其应用。     

HJ-1A/B星CCD相机在轨辐射性能检测分析

为检测分析HJ-1A/B星CCD相机在轨辐射探测性能及其辐射定标的有效性,提出了基于多种光学特性地面目标的在轨检测方法。首先,介绍了HJ-1A/B星CCD相机在轨辐射性能检测方法,并基于2013年HJ-1A/B卫星地面同步观测试验数据,获取了HJ-1A/B星过境时刻的卫星入瞳处等效辐亮度。然后以该等效辐亮度为基准,对HJ-1A/B星CCD相机历次在轨辐射定标结果进行检验,分析HJ-1A/B星CCD相机的在轨运行期间辐射探测性能变化趋势。结果表明：HJ-1A/B星在轨运行过程中,辐射性能在不断发生变化;在轨运行5年多时间里,HJ-1A/B星的CCD相机各波段的辐射性能平均衰变量最低为3.7%,最大为39.6%;为保证遥感数据的定量化精度,定期的在轨绝对辐射定标十分必要。     

The generic framing procedure (GFP): an overview

The generic framing procedure (GFP) is a standardized traffic adaptation protocol for broadband transport applications. It provides an efficiency and QoS-friendly mechanism to map either a physical layer or logical link layer signal to a byte-synchronous channel. It also supports basic client control functions for client management purposes. This article presents a brief overview of GFP     

A General Approach to Probe Dynamic Operation and Carrier Mobility in Field‐Effect Transistors with Nonuniform Accumulation

Revealing the intrinsic electrical properties is the basis of understanding new functional materials and developing their applications. However, in nonideal field‐effect transistors (FETs), conventional current–voltage characterizations do not accurately probe charge transport, particularly for newly developed semiconductors. Here, a generalized gated four‐probe (G‐GFP) technique is developed, which detects dynamic changes in carrier accumulation and transport. The technique is suitable for exploring the intrinsic properties of semiconductors in FETs with arbitrary contacts and in any operational regimes above the threshold. Application to simulated transistors confirms its accuracy in probing the evolution of channel potential, drift field, and gate‐dependent carrier mobility for devices with a contact‐limited operation and disordered semiconductors. Comparative experiments are performed based on FETs with various materials, device structures, and operational temperatures. The G‐GFP technique proves to exclude the various injection properties, to detect in situ how carriers are accumulated, and to clarify carrier mobility of the semiconductors. In particular, the well‐known “double‐slope” features in the current–voltage relations are controllably generated and their origins are identified. The approach could be used to explore electronic properties of newly developed materials such as organic, oxide, or 2D semiconductors.     

A single chip regenerator for transmission systems operating in the range 2-320 Mbits/s

Circuit and operational details of a single chip regenerator, developed by BTRL, are presented. The device is capable of operation over the entire span of currently agreed CCITT hierarchical transmission levels from 2 Mbit/s to 140 Mbits/s. Extension to 280 Mbits/s (320 MBd when coded by 7B8B for optical system applications) is also demonstrated to be possible.     

Modulation and coding for satellite and space communications

Several modulation and coding advances supported by NASA are summarized. To support long-constraint-length convolutional code, a VLSI maximum-likelihood decoder, utilizing parallel processing techniques, which is being developed to decode convolutional codes of constraint length 15 and a code rate as low as 1/6 is discussed. A VLSI high-speed 8-b Reed-Solomon decoder which is being developed for advanced tracking and data relay satellite (ATDRS) applications is discussed. A 300-Mb/s modem with continuous phase modulation (CPM) and codings which is being developed for ATDRS is discussed. Trellis-coded modulation (TCM) techniques are discussed for satellite-based mobile communication applications     

FPGA Implementation of Cross Virtual Concatenation Transmitter/ Receiver for Data Transmission over Next Generation SDH Systems

Cross Virtual Concatenation is the new technique proposed for bandwidth efficient transmission of data over SDH networks. SDH networks came into existence for reliable voice transmission. As the demand of data traffic grew in wide area networks, new technologies were developed and standardized for data transmission over SDH networks. The technologies used namely, GFP (generic framing procedure), VCAT (virtual concatenation) and LCAS (link capacity adjustment scheme) enable network operator to provide integrated voice and data services over their legacy SDH infrastructure. Data packets are encapsulated using framing protocols GFP. VCAT is a process of distributing the GFP framed data payload in number of virtual channels of same capacity forming a Virtually Concatenated Group (VCG). LCAS is used for dynamic bandwidth allocation. LCAS enhances the VCAT scheme with hitless in service addition and removal of VC’s to/from the VCG.VCAT combines homogeneous virtual channels together which in some cases limits the performance of VCAT. This paper describes the implementation of new concatenation technology named cross virtual concatenation (CVC), which combines heterogeneous VC’s together to utilize the SDH bandwidth more efficiently. CVC implementation requires only end node equipments to be upgraded as VCG members travel through the link similar to the conventional VCAT. This paper proposes FPGA implementation of transmitter and receiver circuits for 100 Mbps Ethernet data transmission over next Generation SDH systems using CVC, where two types of VC’s namely VC-3 and VC-12 are used for data transmission. Total Transmission delay is calculated as 125 μs. There is no complexity added at the receiver side due to this delay. The receiver is designed for 32 ms differential delay compensation which can be increased up to maximum 256 ms by increasing the buffer size at the receiver.     

A new multiplexed electrode-per-bit structure for a 64-kbit charge-coupled-device memory

An advanced form of the multiplexed electrode-per-bit (ME/B) structure is described for CCD memory applications. In the new structure, a merging serial register is combined with an ME/B array to make a practical and flexible CCD array. The resulting structure is called the merging ME/B (M/SUP 2/E/B). An n-channel two-level polysilicon-gate structure with ion-implanted barriers and offset CCD clocks lead to a simple rectangular layout, in addition to low power consumption. A 64-kbit CCD memory utilising the structure was designed and tested. The memory operates typically at 5-Mbits/s data rate, while a 512-bit test array is operated in less than 140-ns transfer execution time.     

微杯电子纸及其后加工制程

SiPix利用独特的微杯(Microcup)结构和顶部灌注封装技术，通过连续整卷高速涂布的制程成功地制造出高性能的双稳性、装填电泳微粒的电子纸。SiPix可提供下列两种规格形式任意的EPD卷式成品：(A)用于有源矩阵EPD和直接驱动产品的可剥离保护膜／已灌装及密封的Microcup／无图案导体膜夹层卷；及（P）用于无源矩阵的行导体膜／已灌装及密封的Microcup／列导体膜夹层卷。已经开发出将EPD卷制成不同的显示模块或产品的简单的后续加工制程。     

Spatially complete global spectral surface albedos: value-added datasets derived from Terra MODIS land products

Recent production of land surface anisotropy, diffuse bihemispherical (white-sky) albedo, and direct-beam directional hemispherical (black-sky) albedo from observations acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the National Aeronautics and Space Administration's Terra and Aqua satellite platforms have provided researchers with unprecedented spatial, spectral, and temporal information on the land surface's radiative characteristics. Cloud cover, which curtails retrievals, and the presence of ephemeral and seasonal snow limit the snow-free data to approximately half the global land surfaces on an annual equal-angle basis. This precludes the MOD43B3 albedo products from being used in some remote sensing and ground-based applications, climate models, and global change research projects. An ecosystem-dependent temporal interpolation technique is described that has been developed to fill missing or seasonally snow-covered data in the official MOD43B3 albedo product. The method imposes pixel-level and local regional ecosystem-dependent phenological behavior onto retrieved pixel temporal data in such a way as to maintain pixel-level spatial and spectral detail and integrity. The phenological curves are derived from statistics based on the MODIS MOD12Q1 IGBP land cover classification product geolocated with the MOD43B3 data. The resulting snow-free value-added products provide the scientific community with spatially and temporally complete global white- and black-sky surface albedo maps and statistics. These products are stored on 1-min and coarser resolution equal-angle grids and are computed for the first seven MODIS wavelengths, ranging from 0.47-2.1 /spl mu/m and for three broadband wavelengths 0.3-0.7, 0.3-5.0, and 0.7-5.0 /spl mu/m.     

Synthesis,Characterization, and Application of Antibody Functionalized Fluorescent Silica Nanoparticles

Fluorescent silica nanoparticles (FSNs) are prepared by incorporating dye into a mesoporous silica nanoparticle (MSN) synthesis procedure. FSNs containing sulforhodamine B, hydrophobically modified sulforhodamine B, and Cascade Blue hydrazide are made. The MSN‐based FSNs do not leach dye under simulated physiological conditions and have strong, stable fluorescence. FSNs prepared with sulforhodamine B are compared to FSNs prepared with hydrophobically modified sulforhodamine B. The data indicate that FSNs prepared with sulforhodamine B are equally as stable but twice as fluorescent as particles made with hydrophobically modified sulforhodamine B. The fluorescence of a FSN prepared with sulforhodamine B is 10 times more intense than the fluorescence of a 4.5 nm core–shell CdSe/ZnS quantum dot. For diagnostic applications, a method to selectively and covalently bind antibodies to the surface of the FSNs is devised. FSNs that are functionalized with antibodies specific for Neisseria gonorrhoeae specifically bind to Neisseria gonorrhoeae in flow cytometry experiments, thus demonstrating the functionality of the attached antibodies and the potential of MSN‐based FSNs to be used in diagnostic applications.     

LSI Processor for Digital Signal Processing and Its Application to 4800 Bit/s Modem

This paper describes a fast data processing LSI unit tailored to the digital signal processing (DSP) applications in the field of electrical communications. The results of successful application to the 4800 bit/s modem are also given. The LSI processor discussed here adopts a firmware control scheme to enhance the flexibility and freedom of application and extensively utilizes the pipeline processing technique to attain high speed data handling capability. The various operations encountered in DSP systems are unified into one operation of the typeA times B + C rightarrow Dand the LSI processor is designed to continuously perform this operation, while the data to be operated are transferred sequentially into the processor controlled by exterior firmware. The developed LSI handles 8 bit data at the clock frequency of 1.152 MHz and manages 144 K operations per second (6.9 μs cycle time). The LSI is an N-MOS chip containing 1500 gates and packaged in a 40 pin DIP. The automatic equalizer for 4800 bit/s modem was implemented using two of the developed LSI processors and about 4 K ROM and 1 K RAM memory chips. The measurement on this modem gave the error rate of 10^-5atS/N = 17.6dB and error free phase jitter allowance of 55° p-p. Application of the LSI processor to digital filters for roll-off spectrum shaping and timing signal extraction is also described.     

带校准系数的数字温湿度传感器及其应用

介绍基于新型湿度传感器HIH4000及数字温度传感器DSISB20开发的新型数字温温度传感器．它所具有的可靠性、准确性、稳定性、自带校准系数等性能是传统传感器无法达到的。并给出实际的应用电路。     

Standardization on multimedia communications:computer-telephony-integration-related issues

Computer-telephony integration (CTI) has been developed since the 1960s. It is one of the major emerging multimedia communications applications. It provides enhanced telecommunications services controlled by a computer, that is by integrating the call handling capabilities of PBXs and the data processing capabilities of computers. CTI applications have become more popular and widespread with the rapid and deep penetration of personal computers and the dramatic growth of the Internet since the mid-1990s. CTI applications are being enhanced by means of more integration with Internet capabilities. Several standardization organizations and fora/consortia are developing standards/specifications for CTI in order to cope with the growing demand for multimedia communications. This article describes a brief historical sketch and the state of the art of CTI-related standards and specifications, which are still being developed     

Bit-serial VLSI implementation of delayed LMS adaptive FIR filters

The delayed least-mean-square (DLMS) algorithm is useful for adaptive finite impulse response (FIR) filtering applications where high throughput rates are required. In the paper, a bit-serial bit-level systolic array based on new schemes for multiplication and inner-product computation is presented to implement DLMS adaptive N-tap FIR filters. The architecture is highly regular, modular, and thus well-suited to VLSI implementation. It has an efficiency of 100% and a throughput rate of one filter output per 2B cycles, where B is the word length of input data. In addition, the proposed array uses a small delay of [(4B+N/2+4)/2B] in the filter coefficient adaptation, where [x] is the smallest integer greater than or equal to x. This ensures that the DLMS algorithm can have good performance under proper selection of the step size. Based on a conservative design technique of static complementary metal oxide semiconductor (CMOS) logic, it is shown that the proposed system can be realized in a single chip for most practical applications     

Sub-nanosecond pulse-forming network on SiGe BiCMOS for UWB communications

A pulse-forming network (PFN) has been developed for ultra-wideband (UWB) communication systems. This PFN generates sub-nanosecond pulses at a pulse repetition frequency (PRF) of >500 MHz for high data-rate applications like wireless video streaming. To generate the pulses, the PFN performs two operations on an input data signal: it decreases the signal rise time, then it differentiates the signal. The differentiation circuit is a frequency-dependent negative-feedback system. The PFN is fabricated in SiGe BiCMOS with an active die size of less than 0.25 mm/sup 2/, and it requires 3.3-V 20-mA dc during operation. Measured performance is validated at 500-MHz PRF, achieving pulsewidth of 175 ps and pulse amplitude of 0.17 V. The PFN is also validated within a transmitter system that transmits Manchester coded pseudorandom bit sequence. Measured effective isotropic radiated power of the transmitter shows that the PFN output power is sufficient to meet the Federal Communications Commission's emission limits, thus eliminating the need of amplification before transmission.