外文翻译 英文文献 中英版 基于Win CE的ADSL线路参数的研究.doc

（外文翻译原文）ADSL line parameters research based on WIN CE Author:Kubilay Atasu Lu BreveglieriWindows CE (also known officially as Windows Embedded CE since version 6.023, and sometimes abbreviated WinCE) is a variation of Microsoft's Windows operating system for minimalistic computers and embedded systems. Windows CE is a distinctly different kernel, rather than a trimmed-down version of desktop Windows. It is not to be confused with Windows XP Embedded which is NT-based. It is supported on Intel x86 and compatibles, MIPS, ARM, and Hitachi SuperH processors. 1.Features：Windows CE is optimized for devices that have minimal storagea Windows CE kernel may run in under a megabyte of memory. Devices are often configured without disk storage, and may be configured as a “closed” system that does not allow for end-user extension (for instance, it can be burned into ROM). Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt latency. It supports 256 priority levels and uses priority inheritance for dealing with priority inversion. The fundamental unit of execution is the thread. This helps to simplify the interface and improve execution time. Microsoft has stated that the CE is not an intentional initialism, but many people believe CE stands for Consumer Electronics or Compact Edition; users often disparagingly called it “Wince”. Microsoft says it implies a number of Windows CE design precepts, including “Compact, Connectable, Compatible, Companion, and Efficient.”The first version, known during development under the codename “Pegasus”, featured a Windows-like GUI and a number of Microsoft's popular applications, all trimmed down for smaller storage, memory, and speed of the palmtops of the day. Since then, Windows CE has evolved into a component-based, embedded, real-time operating system. It is no longer targeted solely at hand-held computers. Many platforms have been based on the core Windows CE operating system, including Microsoft's AutoPC, Pocket PC 2000, Pocket PC 2002, Windows Mobile 2003, Windows Mobile 2003 SE, Windows Mobile 5.0, Windows Mobile 6, Smartphone 2002, Smartphone 2003 and many industrial devices and embedded systems. Windows CE even powered select games for the Sega Dreamcast, was the operating system of the controversial Gizmondo handheld, and can partially run on modified Microsoft Xbox game consoles. A distinctive feature of Windows CE compared to other Microsoft operating systems is that large parts of it are offered in source code form. First, source code was offered to several vendors, so they could adjust it to their hardware. Then products like Platform Builder (an integrated environment for Windows CE OS image creation and integration, or customized operating system designs based on CE) offered several components in source code form to the general public. However, a number of core components that do not need adaptation to specific hardware environments (other than the CPU family) are still distributed in binary form only. 2.Development tools： Visual Studio,Late versions of Microsoft Visual Studio support projects for Windows CE / Windows Mobile, producing executable programs and platform images either as an emulator or attached by cable to an actual mobile device. A mobile device is not necessary to develop a CE program. The .NET Compact Framework supports a subset of the .NET Framework with projects in C# and VB.NET, but not Managed C+. Platform Builder,This programming tool is used for building the platform (BSP + Kernel), device drivers (shared source or custom made) and also the application. This is a one step environment to get the system up and running. One can also use Platform Builder to export an SDK (standard development kit) for the target microprocessor (SuperH, x86, MIPS, ARM etc.) to be used with another associated tool set named below.Embedded Visual C+ (eVC) ,The Embedded Visual C+ tool is for development of embedded application for Windows CE based devices. This tool can be used standalone using the SDK exported from Platform Builder or using the Platform Builder using the Platform Manager connectivity setup. 3.Relationship to Windows Mobile, Pocket PC, and SmartPhone： Often Windows CE, Windows Mobile, and Pocket PC are used interchangeably. This practice is not entirely accurate. Windows CE is a modular/componentized operating system that serves as the foundation of several classes of devices. Some of these modules provide subsets of other components' features (e.g. varying levels of windowing support; DCOM vs COM), others which are mutually exclusive (Bitmap or TrueType font support), and others which add additional features to another component. One can buy a kit (the Platform Builder) which contains all these components and the tools with which to develop a custom platform. Applications such as Excel Mobile/Pocket Excel are not part of this kit. The older Handheld PC version of Pocket Word and several other older applications are included as samples, however. Windows Mobile is best described as a subset of platforms based on a Windows CE underpinning. Currently, Pocket PC (now called Windows Mobile Classic), SmartPhone (Windows Mobile Standard), and PocketPC Phone Edition (Windows Mobile Professional) are the three main platforms under the Windows Mobile umbrella. Each platform utilizes different components of Windows CE, as well as supplemental features and applications suited for their respective devices. Pocket PC and Windows Mobile is a Microsoft-defined custom platform for general PDA use, and consists of a Microsoft-defined set of minimum profiles (Professional Edition, Premium Edition) of software and hardware that is supported. The rules for manufacturing a Pocket PC device are stricter than those for producing a custom Windows CE-based platform. The defining characteristics of the Pocket PC are the digitizer as the primary Human Interface Device and its extremely portable size. The SmartPhone platform is a feature rich OS and interface for cellular phone handsets. SmartPhone offers productivity features to business users, such as email, as well as multimedia capabilities for consumers. The SmartPhone interface relies heavily on joystick navigation and PhonePad input. Devices running SmartPhone do not include a touchscreen interface. SmartPhone devices generally resemble other cellular handset form factors, whereas most Phone Edition devices use a PDA form factor with a larger display. Competitors to consumer CE based PDA platforms like Pocket PC the main application of Windows CE are Java, Symbian OS, Palm OS, iPhone OS and Linux based packages like Qtopia Embedded Linux environment from Trolltech, Convergent Linux Platform from a La Mobile, and Access Linux Platform from Orange and Access. The secondary usage of CE is in devices in need of graphical user interfaces, (point of sale terminals, media centers, web tablets, thin clients) as the main selling point CE is the look and feel being similar to desktop Windows. The competition is Windows XP, Linux and graphical packages for simpler embedded operating systems. Being an RTOS, Windows CE is also theoretically a competitor to any realtime operating system in the embedded space, like VxWorks, ITRON or eCos. The dominating method, however, of mixing Windows look and feel with realtime on the same hardware, is to run double operating systems using some virtualization technology, like TRANGO Hypervisor from TRANGO Virtual Processors or Intime from TenAsys in the case of Windows, and OS Ware from VirtualLogix, Padded Cell from Green Hills Software, OKL4 from Open Kernel Labs, TRANGO Hypervisor from TRANGO Virtual Processors, RTS Hypervisor from Real-Time Systems or PikeOS from Sysgo, in case of the competition. Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call. A splitter - or microfilter - allows a single telephone connection to be used for both ADSL service and voice calls at the same time. Because phone lines vary in quality and were not originally engineered with DSL in mind, it can generally only be used over short distances, typically less than 3mi (5.5 km) William Stallings' book. The distinguishing characteristic of ADSL over other forms of DSL is that the volume of data flow is greater in one direction than the other, i.e. it is asymmetric. Providers usually market ADSL as a service for consumers to connect to the Internet in a relatively passive mode: able to use the higher speed direction for the "download" from the Internet but not needing to run servers that would require high speed in the other direction. 4.How ADSL works vand installation issues： Currently, most ADSL communication is full duplex. Full duplex ADSL communication is usually achieved on a wire pair by either frequency division duplex (FDD), echo canceling duplex (ECD), or time division duplexing (TDD). FDM uses two separate frequency bands, referred to as the upstream and downstream bands. The upstream band is used for communication from the end user to the telephone central office. The downstream band is used for communicating from the central office to the end user. With standard ADSL (annex A), the band from 25.875 kHz to 138 kHz is used for upstream communication, while 138 kHz 1104 kHz is used for downstream communication. Each of these is further divided into smaller frequency channels of 4.3125 kHz. During initial training, the ADSL modem tests which of the available channels have an acceptable signal-to-noise ratio. The distance from the telephone exchange, noise on the copper wire, or interference from AM radio stations may introduce errors on some frequencies. By keeping the channels small, a high error rate on one frequency thus need not render the line unusable: the channel will not be used, merely resulting in reduced throughput on an otherwise functional ADSL connection. Due to the way it uses the frequency spectrum, ADSL deployment presents some issues. It is necessary to install appropriate frequency filters at the customer's premises, to avoid interferences with the voice service, while at the same time taking care to keep a clean signal level for the ADSL connection. installation required a technician to visit the premises. A splitter was installed near the demarcation point, from which a dedicated data line was installed. This way, the DSL signal is separated earlier and is not attenuated inside the customer premises. However, this procedure is costly, and also caused problems with customers complaining about having to wait for the technician to perform the installation. As a result, many DSL vendors started offering a self-install option, in which they ship equipment and instructions to the customer. When the first side from the bureau to install a telephone line access to the input signal separator, and then use a phone line in front of Flanagan ready signal splitter to connect the voice signal output port, the other end to connect to your telephone. At this point you should have been able to answer the telephone and dial telephone.（外文翻译译文）基于Win CE的ADSL线路参数的研究Windows CE（也称作为Windows Embedded CE，至今发布的最新版本：6.0 2 3，有时简称WinCE）是从微软的Windows操作系统和嵌入式系统变化而来。Windows CE的内核与众不同，不是精简式的桌面Windows的版本。不可与基于NT的嵌入式Windows XP混淆。它支持英特尔x86，MIPS，ARM公司和日立的SuperH处理器。1.特征： Windows CE对嵌入式设备进行优化，具有较小的存储空间，一个Windows CE内核可以运行在兆字节的内存空间下，相关设备往往没有磁盘存储配置，并可以被配置为不允许使用最终用户扩展名的“封闭”系统，（而且，它可以“烧写”到ROM）。 Windows CE符合实时操作系统的定义，可确定中断延迟时间。它支持256个优先级，并使用优先级倒置与优先级继承。执行的基本单位是线程。这有助于简化界面，提高执行时间。 微软表示，'CE'是不是故意的缩写，用户经常简单地称之为“WINCE”。微软称，它意味着一种Windows CE的设计原理，包括“结构紧凑，可连接，兼容，高效。”WINCE的第一个版本，在开发过程中已知的代号为“Pegasus”，降低WINCE的存储空间和记忆能力，和现如今掌上电脑的速度,其如Windows的图形用户界面功能很受微软用户的欢迎， 自那时以来，Windows CE已发展成为一个基于组件的、嵌入式的实时操作系统，它不再是只针对手持电脑。支持多平台是Windows CE操作系统的核心，包括微软的车载电脑，Pocket PC2000，Pocket PC 2002，Windows Mobile 2003，Windows Mobile 2003，Windows Mobile 5.0，Windows Mobile 6，Smartphone 2003和许多工业设备和嵌入式系统。 Windows CE甚至为世嘉Dreamcast提供游戏选择，并可以在一定程度上进行修订微软Xbox游戏机。 独具特色的WindowsCE相对其他微软操作系统，它的大部份功能部件都以源代码形式提供。首先，源代码提供给几家厂商，所以他们可以调整其系统以适合自己的硬件。然后，一些产品如Platform Builder为Windows CE操作系统创建系统映像，集成或定制操作系统（一个基于WINCE的集成设计环境），所提供的源代码部分公开于大众。然而，一些不需要适应一些特定的硬件环境的核心组件（除CPU系列）仍然只以二进制形式公开。 2.开发工具:Visual Studio： 较新版本的Microsoft Visual Studio的Windows CE工程，支持项目： WindowsMobile，无论是作为一个仿真器或通过电缆连接到一个实际的移动设备的图像，产生可执行程序。一个移动设备是没有必要制定Wince程序的。.NET Compact Framework支持的.NET框架支持C和VB.NET，但并不管理C + +。 平台定制器(Platform Builder)：该编程工具的用途为：定制平台（BSP+内核），设备驱动程序（共享源代码或定制），和开发应用程序。一次环境配置就可让系统启动和运行。也可以使用Platform Builder为目标处理器导出一个SDK（标准开发包）（相关处理器如：SuperH，x86，MIPS，ARM等），并与另一相关的工具设置命名。Embedded Visual C+ (eVC),为基于Wince的嵌入式应用程序的开发工具，此开发工具，能够利用标准的SDK，或是从PB中定制出的，从而开发应用程序。3.与Windows Mobile，Pocket PC和智能手机的关系： 通常情况下，Windows CE，Windows Mobile和Pocket PC是交杂使用。这种做法不完全准确。 Windows CE是一个模块化/组件化的操作系统。这些模块提供了一些其他组件的功能集（例如，不同的窗口支持 DCOM和COM）的，有些则是互相排斥（图或TrueType字体支持），有些则添加额外的功能。人们可以购买一个工具包（Platform Builder），它包含了所有这些组件来开发定制平台。Excel移动应用， Pocket Excel不属于此工具包。尽管如此，旧版本手持的Pocket Word和其他一些旧的应用程序作为样本包括这些功能。 Windows Mobile被最好的形容为一个基于WindowsCE下的一个子集。目前，Pocket PC (现在称为经典Windows Mobile)，智能手机（Windows Mobile的标准），电话和Pocket PC电话版（专业Windows Mobile）是三个Windows Mobile的主要平台。每个平台采用含有不同组件的Windows CE系统，以及各自含有适合的应用设备补充其功能。 Pocket PC和Windows Mobile是微软自定义的一般PDA使用的平台，和微软组成按一套明确的最低配置（专业版，高级版）的软件和硬件支持。制造Pocket PC设备的规则严格高于生产定制且基于Windows CE平台的。在Pocket PC中的定义性特征是作为主要的人机接口设备，其极具便携式特征。 智能手机平台是一个功能丰富的操作系统且具有移动电话手机的界面。智能手机提供各种商业功能，商业用户，如电子邮件，以及CE的多媒体功能。智能手机界面极为依赖操纵杆导航和PhonePad。设备上运行的智能手机不包括触摸屏接口。智能手机产品一般都像其他的手机的外形，而大多数Phone Edition设备使用一台PDA。 关于竞争产品，Windows CE的竞争对手的PDA平台，像Pocket PC ,Windows CE的主要应用,是Java，Symbian操作系统，Palm操作系统，iPhone操作系统和基于Linux的嵌入式系统。Windows CE二次使用的设备是在图形用户界面中的需要，（销售终端，媒体中心，瘦客户机为Windows CE主要应用），外观类似Windows桌面。和Windows CE竞争的一般为：Windows XP，Linux和简单的图形套件的嵌入式操作系统。 作为一个实时操作系统，从理论上说Windows CE与任何一个竞争对手在嵌入式实时操作系统领域中如VxWorks，Itron公司或eCos相比，占据领先地位，考虑到Windows混合性和硬件上的实时性，在众多的操作系统中，是运行在Windows和TenAsys双操作系统中使用的一些虚拟化技术，如TRANGO管理程序。非对称数字用户线路（ADSL）是DSL的一种形式，这种数据通信技术实现了更快的数据传输，比较传统的声带调制解调器，可以提供跨越电话线传输的形式。它通过利用未通过语音电话使用的频率，经过分配器和滤波器，允许一个单一的电话连接既可以同时使用ADSL服务和语音呼叫服务。由于电话线质量各不相同，预先设计中并没有将DSL的能耗考虑在内，它通常只用于短距离传输，一般小于3mi（5.5公里）威廉斯托林斯的书中提到。 ADSL的全称是非对称数字式用户线路，是一种可以让家庭或小型企业利用现有电话网采用高频数字压缩方式，由网络服务提供商ISP进行宽带接入的技术。由于从ISP端到用户端（下行）需要大带宽来支持，而从用户端到ISP端（上行）只需要小量带宽即可，因此这种接入方式称之为“非对称”数字式用户线路。4.ADSL如何工作及安装问题：ADSL与传统的调制解调器和ISDN一样，是使用电话网作为传输的媒介。当在一对电话线的两端分别安置一个ADSL设备时，利用现代分频和编码调制技术，就能够在这段电话线上产生三个信息通道：高速的下传通道（1.5-1.8M/S）、中速的双工通道和普通的电话通道，这三个通道可以同时工作。也就是说它能够在现有的电话线上获得最大的数据传输能力，这样用户在一条电话线上既可以上网快速“冲浪”，还可以打电话发送传真，而不影响通话质量或降低上网速度。具体工作流程是:经ADSL Modem编码后的信号通过电话线传到电信局后再通过一个信号识别/分离器，如果是语音信号就传到电话交换机上，如果是数字信号就接入Internet。