外文翻譯 英文文獻(xiàn) 中英版 基于Win CE的ADSL線路參數(shù)的研究.doc

（外文翻譯原文）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 microsofts 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 microsofts 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 microsofts 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 customers 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.（外文翻譯譯文）基于win ce的adsl線路參數(shù)的研究windows ce（也稱(chēng)作為windows embedded ce，至今發(fā)布的最新版本：6.0 2 3，有時(shí)簡(jiǎn)稱(chēng)wince）是從微軟的windows操作系統(tǒng)和嵌入式系統(tǒng)變化而來(lái)。windows ce的內(nèi)核與眾不同，不是精簡(jiǎn)式的桌面windows的版本。不可與基于nt的嵌入式windows xp混淆。它支持英特爾x86，mips，arm公司和日立的superh處理器。1.特征： windows ce對(duì)嵌入式設(shè)備進(jìn)行優(yōu)化，具有較小的存儲(chǔ)空間，一個(gè)windows ce內(nèi)核可以運(yùn)行在兆字節(jié)的內(nèi)存空間下，相關(guān)設(shè)備往往沒(méi)有磁盤(pán)存儲(chǔ)配置，并可以被配置為不允許使用最終用戶(hù)擴(kuò)展名的“封閉”系統(tǒng)，（而且，它可以“燒寫(xiě)”到rom）。 windows ce符合實(shí)時(shí)操作系統(tǒng)的定義，可確定中斷延遲時(shí)間。它支持256個(gè)優(yōu)先級(jí)，并使用優(yōu)先級(jí)倒置與優(yōu)先級(jí)繼承。執(zhí)行的基本單位是線程。這有助于簡(jiǎn)化界面，提高執(zhí)行時(shí)間。 微軟表示，ce是不是故意的縮寫(xiě)，用戶(hù)經(jīng)常簡(jiǎn)單地稱(chēng)之為“wince”。微軟稱(chēng)，它意味著一種windows ce的設(shè)計(jì)原理，包括“結(jié)構(gòu)緊湊，可連接，兼容，高效?！眞ince的第一個(gè)版本，在開(kāi)發(fā)過(guò)程中已知的代號(hào)為“pegasus”，降低wince的存儲(chǔ)空間和記憶能力，和現(xiàn)如今掌上電腦的速度,其如windows的圖形用戶(hù)界面功能很受微軟用戶(hù)的歡迎， 自那時(shí)以來(lái)，windows ce已發(fā)展成為一個(gè)基于組件的、嵌入式的實(shí)時(shí)操作系統(tǒng)，它不再是只針對(duì)手持電腦。支持多平臺(tái)是windows ce操作系統(tǒng)的核心，包括微軟的車(chē)載電腦，pocket pc2000，pocket pc 2002，windows mobile 2003，windows mobile 2003，windows mobile 5.0，windows mobile 6，smartphone 2003和許多工業(yè)設(shè)備和嵌入式系統(tǒng)。 windows ce甚至為世嘉dreamcast提供游戲選擇，并可以在一定程度上進(jìn)行修訂微軟xbox游戲機(jī)。 獨(dú)具特色的windowsce相對(duì)其他微軟操作系統(tǒng)，它的大部份功能部件都以源代碼形式提供。首先，源代碼提供給幾家廠商，所以他們可以調(diào)整其系統(tǒng)以適合自己的硬件。然后，一些產(chǎn)品如platform builder為windows ce操作系統(tǒng)創(chuàng)建系統(tǒng)映像，集成或定制操作系統(tǒng)（一個(gè)基于wince的集成設(shè)計(jì)環(huán)境），所提供的源代碼部分公開(kāi)于大眾。然而，一些不需要適應(yīng)一些特定的硬件環(huán)境的核心組件（除cpu系列）仍然只以二進(jìn)制形式公開(kāi)。 2.開(kāi)發(fā)工具:visual studio： 較新版本的microsoft visual studio的windows ce工程，支持項(xiàng)目： windowsmobile，無(wú)論是作為一個(gè)仿真器或通過(guò)電纜連接到一個(gè)實(shí)際的移動(dòng)設(shè)備的圖像，產(chǎn)生可執(zhí)行程序。一個(gè)移動(dòng)設(shè)備是沒(méi)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 + +。 平臺(tái)定制器(platform builder)：該編程工具的用途為：定制平臺(tái)（bsp+內(nèi)核），設(shè)備驅(qū)動(dòng)程序（共享源代碼或定制），和開(kāi)發(fā)應(yīng)用程序。一次環(huán)境配置就可讓系統(tǒng)啟動(dòng)和運(yùn)行。也可以使用platform builder為目標(biāo)處理器導(dǎo)出一個(gè)sdk（標(biāo)準(zhǔn)開(kāi)發(fā)包）（相關(guān)處理器如：superh，x86，mips，arm等），并與另一相關(guān)的工具設(shè)置命名。embedded visual c+ (evc),為基于wince的嵌入式應(yīng)用程序的開(kāi)發(fā)工具，此開(kāi)發(fā)工具，能夠利用標(biāo)準(zhǔn)的sdk，或是從pb中定制出的，從而開(kāi)發(fā)應(yīng)用程序。3.與windows mobile，pocket pc和智能手機(jī)的關(guān)系： 通常情況下，windows ce，windows mobile和pocket pc是交雜使用。這種做法不完全準(zhǔn)確。 windows ce是一個(gè)模塊化/組件化的操作系統(tǒng)。這些模塊提供了一些其他組件的功能集（例如，不同的窗口支持 dcom和com）的，有些則是互相排斥（圖或truetype字體支持），有些則添加額外的功能。人們可以購(gòu)買(mǎi)一個(gè)工具包（platform builder），它包含了所有這些組件來(lái)開(kāi)發(fā)定制平臺(tái)。excel移動(dòng)應(yīng)用， pocket excel不屬于此工具包。盡管如此，舊版本手持的pocket word和其他一些舊的應(yīng)用程序作為樣本包括這些功能。 windows mobile被最好的形容為一個(gè)基于windowsce下的一個(gè)子集。目前，pocket pc (現(xiàn)在稱(chēng)為經(jīng)典windows mobile)，智能手機(jī)（windows mobile的標(biāo)準(zhǔn)），電話和pocket pc電話版（專(zhuān)業(yè)windows mobile）是三個(gè)windows mobile的主要平臺(tái)。每個(gè)平臺(tái)采用含有不同組件的windows ce系統(tǒng)，以及各自含有適合的應(yīng)用設(shè)備補(bǔ)充其功能。 pocket pc和windows mobile是微軟自定義的一般pda使用的平臺(tái)，和微軟組成按一套明確的最低配置（專(zhuān)業(yè)版，高級(jí)版）的軟件和硬件支持。制造pocket pc設(shè)備的規(guī)則嚴(yán)格高于生產(chǎn)定制且基于windows ce平臺(tái)的。在pocket pc中的定義性特征是作為主要的人機(jī)接口設(shè)備，其極具便攜式特征。 智能手機(jī)平臺(tái)是一個(gè)功能豐富的操作系統(tǒng)且具有移動(dòng)電話手機(jī)的界面。智能手