信息与通信工程专业英语

1、Lesson Six Technology of Modern CommunicationText A: BluetoothBluetooth wireless technology is a short-range communications technology intended to replace the cables connecting portable and fixed devices while maintaining high levels of security. The key features of Bluetooth technology are robustne

2、ss, low power, and low cost. The Bluetooth specification defines a uniform structure for a wide range of devices to connect and communicate with each other.Bluetooth technology has achieved global acceptance such that any Bluetooth enabled device, almost everywhere in the world, can connect to other

3、 Bluetooth enabled devices in proximity. Bluetooth enabled electronic devices connect and communicate wirelessly through short-range, ad hoc networks known as piconets. Each device can simultaneously communicate with up to seven other devices within a single piconet. Each device can also belong to s

4、everal piconets simultaneously. Piconets are established dynamically and automatically as Bluetooth enabled devices enter and leave radio proximity.A fundamental Bluetooth wireless technology strength is the ability to simultaneously handle both data and voice transmissions. This enables users to en

5、joy variety of innovative solutions such as a hands-free headset for voice calls, printing and fax capabilities, and synchronizing PDA, laptop, and mobile phone applications to name a few.core systemThe Bluetooth core system, defined by Bluetooth specification, is a common service layer protocol whi

6、ch covers four lower layers in seven layer protocol. Service Discovery Protocol (SDP and the overall profile requirements are defined by Generic Access Profile (GAP. A complete Bluetooth application requires a number of additional services and higher layer protocols that are defined in the Bluetooth

7、 specification.The lowest three layers are sometimes grouped into a subsystem known as the Bluetooth controller. This is a common implementation involving a standard physical communications interface between the Bluetooth controller and remainder of the Bluetooth system including the L2CAP, service

8、layers and higher layers (known as the Bluetooth host. Although this interface is optional, the architecture is designed to allow for its existence and characteristics. The Bluetooth specification enables interoperability between independent Bluetooth enabled systems by defining the protocol message

9、s exchanged between equivalent layers, and also interoperability between independent Bluetooth sub-systems by defining a common interface between Bluetooth controllers and Bluetooth hosts.A number of functional blocks are shown and the path of services and data between these. The functional blocks s

10、hown in the diagram are informative; in general the Bluetooth specification·100·does not define the details of implementations except where this is required for interoperability.Standard interactions are defined for all inter-device operation, where Bluetooth devices exchange protocol sign

11、aling according to the Bluetooth specification. The Bluetooth core system protocols are the radio (RF protocol, link control (LC protocol, link manager (LM protocol and logical link control and adaptation protocol (L2CAP, all of which are fully defined in subsequent parts of the Bluetooth specificat

12、ion. In addition, the service discovery protocol (SDP is a service layer protocol required by all Bluetooth applications.The Bluetooth core system offers services through a number of service access points that are shown in the diagram as ellipses. These services consist of the basic primitives that

13、control the Bluetooth core system. The services can be split into three types. There are device control services that modify the behavior and modes of a Bluetooth device, transport control services that create, modify and release traffic bearers (channels and links, and data services that are used t

14、o submit data for transmission over traffic bearers. It is common to consider the first two as belonging to the C-plane and the last as belonging to the U-plane.A service interface to the Bluetooth controller sub-system is defined such that the Bluetooth controller may be considered a standard part.

15、 In this configuration the Bluetooth controller operates the lowest three layers and the L2CAP layer is contained with the rest of the Bluetooth application in a host system. The standard interface is called the host to controller interface (HCI. Implementation of this standard service interface is

16、optional.As the Bluetooth architecture is defined with the possibility of a separate host and controller communicating through an HCI, a number of general assumptions are made. The Bluetooth controller is assumed to have limited data buffering capabilities in comparison with the host. Therefore the

17、L2CAP layer is expected to carry out some simple resource management when submitting L2CAP PDUs to the controller for transport to a peer device. This includes segmentation of L2CAP SDUs into more manageable PDUs and then the fragmentation of PDUs into start and continuation packets of a size suitab

18、le for the controller buffers, and management of the use of controller buffers to ensure availability for channels with quality of service (QoS commitments.The baseband layer provides the basic ARQ protocol in Bluetooth technology. The L2CAP layer can optionally provide a further error detection and

19、 retransmission to the L2CAP PDUs. This feature is recommended for applications with requirements for a low probability of undetected errors in the user data. A further optional feature of L2CAP is a window-based flow control that can be used to manage buffer allocation in the receiving device. Both

20、 of these optional features augment the QoS performance in certain scenarios.Although these assumptions may not be required for embedded Bluetooth technology implementations that combine all layers in a single system, the general architectural and QoS models are defined with these assumptions in min

21、d, in effect a lowest common denominator.Automated conformance testing of implementations of the Bluetooth core system is required. This is achieved by allowing the tester to control the implementation through the RF interface,·101·which is common to all Bluetooth systems, and through the

22、test control interface (TCI, which is only required for conformance testing.The tester uses exchanges with the implementation under test (IUT through the RF interface to ensure the correct responses to requests from remote devices. The tester controls the IUT through the TCI to cause the IUT to orig

23、inate exchanges through the RF interface so that these can also be verified as conformant.The TCI uses a different command-set (service interface for the testing of each architectural layer and protocol. A subset of the HCI command-set issued as the TCI service interface for each of the layers and p

24、rotocols within the Bluetooth controller subsystem. A separate service interface is used for testing the L2CAP layer and protocol. As an L2CAP service interface is not defined in the Bluetooth core specification it is defined separately in the TCI specification. Implementation of the L2CAP service i

25、nterface is only required for conformance testing.Bluetooth Technology BenefitsWhy Choose Bluetooth wireless technology?Bluetooth wireless technology is the simple choice for convenient, wire-free, and short-range communication between devices. It is a globally available standard that wirelessly con

26、nects mobile phones, portable computers, cars, stereo headsets, MP3 players, and more. Thanks to the unique concept of “profiles”, Bluetooth enabled products do not need to install driver software. The technology is now available in its fourth version of the specification and continues to develop, b

27、uilding on its inherent strengths small-form factor radio, low power, low cost, built-in security, robustness, ease-of-use, and ad hoc networking abilities. Bluetooth wireless technology is the leading and only proven short-range wireless technology on the market today shipping over five million uni

28、ts every week with an installed base of over 500 million units at the end of 2005.Globally AvailableThe Bluetooth wireless technology specification is available free-of-charge to our member companies around the globe. Manufacturers from many industries are busy implementing the technology in their p

29、roducts to reduce the clutter of wires, make seamless connections, stream stereo audio, transfer data or carry voice communications. Bluetooth technology operates in the 2.4 GHz, one of the unlicensed industrial, scientific, medical (ISM radio bands. As such, there is no cost for the use of Bluetoot

30、h technology. While you must subscribe to a cellular provider to use GSM or CDMA, with Bluetooth technology there is no cost associated with the use beyond the cost of your device.Range of DevicesBluetooth technology is available in an unprecedented range of applications from mobile phones to automo

31、biles to medical devices for use by consumers, industrial markets, enterprises,·102·and more. The low power consumption, small size and low cost of the chipset solution enables Bluetooth technology to be used in the tiniest of devices. Have a look at the wide range products made available

32、by our members in the Bluetooth product directory and the component product listing.Ease of UseBluetooth technology is an ad hoc technology that requires no fixed infrastructure and is simple to install and set up. You dont need wires to get connected. The process for a new user is easy you get a Bl

33、uetooth branded product, check the profiles available and connect it to another Bluetooth device with the same profiles. The subsequent PIN code process is as easy as when you identify yourself at the ATM machine. When out-and-about, you carry your personal area network (PAN with you and can even co

34、nnect to others.Globally Accepted SpecificationBluetooth wireless technology is the most widely supported, versatile, and secure wireless standard on the market today. The globally available qualification program tests member products as to their accordance with the standard. Since the first release

35、 of the Bluetooth specification in 1999, over 4000 companies have become members in the Bluetooth Special Interest Group (SIG. Meanwhile, the number of Bluetooth products on the market is multiplying rapidly. Volumes have doubled for the fourth consecutive year and are likely to reach an installed b

36、ase of 500 million units by the close of 2005.Secure ConnectionsFrom the start, Bluetooth technology was designed with security needs in mind. Since it is globally available in the open 2.4 GHz ISM band, robustness was built in from the beginning. With adaptive frequency hopping (AFH, the signal &qu

37、ot;hops" and thus limits interference from other signals. Further, Bluetooth technology has built-in security such as 128bit encryption and PIN code authentication. When Bluetooth products identify themselves, they use the PIN code the first time they connect. Once connected, always securely co

38、nnected.New Words and Expressionsproximity adj. 接近,邻近ad hoc 特别的;变通的,非正式的;(拉丁语 laptop 膝上型轻便电脑ellipse n. 椭圆RF Radio Frequency 射频PDU Protocol Data Unit 协议数据单元peer adj. 对等的fragmentation n. 分区输入程序;碎片·103·commitment n. 行为;委托;义务baseband n. 基带stereo headsets 立体声耳机scenario n. 剧情说明书,电影剧本denominator

39、n.数分母;共同的要素,共同的性质conformance n. 相似;相符;一致clutter n. 混乱seamless adj. 无缝的chipset n. 计芯片集encryption n. 加密authentication n. 认证Notes1. Bluetooth wireless technology is a short-range communications technology intended to replace the cables connecting portable and fixed devices while maintaining high levels

40、 of security.译文:蓝牙无线技术是一种小范围无线通信技术,旨在保持高安全级的基础上,在便携式设备与固定设备之间实现无线连接。2. Radio:蓝牙系统的无线发送层,是该系统的最底层,详细描述了蓝牙设备收发器在无线带宽下的技术规范。对于无线层,定义了两个不同的频率范围:23MHz和79MHz,它们都在2.4GHz ISM的频段内。23MHz范围仅仅用在某些国家(诸如西班牙和法国。3. Piconet:微微网,是由采用蓝牙技术的设备以特定方式组成的网络。微微网的建立以两台设备(如便携式电脑和蜂窝电话的连接开始,最多由8台设备构成。所有的蓝牙设备都是对等的,以同样的方式工作。然而,当一个

41、微微网建立时,只有一台为主设备,其他均为从设备,而且在一个微微网存在期间将一直维持这一状况。所有设备都具有由主设备参数(clock和BD_ADDR定义的同样的物理信道。4. The Bluetooth core system, defined by Bluetooth specification, is a common service layer protocol which covers four lower layers in seven layer protocol. Service Discovery Protocol (SDP and the overall profile req

42、uirements are defined by Generic Access Profile (GAP.译文:蓝牙规范将蓝牙核心系统定义为一个普通的服务层协议,这个服务层覆盖了七层协议的下四层,通用访问应用(GAP定义了服务发现层协议(SDP和所需要的通用协议子集。(1 SDP:Service Discovery Protocol服务发现协议,蓝牙中定义的一个协议,主要用来提供一个方式,通过它能够让应用程序发现和使用有关服务,并且能够知晓这些服务的特点。(2 GAP:Generic Access Profile 通用访问应用,该应用描述了一种设备发现和访问另外一种设备的机制,而此时,这两种设

43、备不共享普通的应用程序。5. The Bluetooth core system protocols are the radio (RF protocol, link control (LC protocol, link manager (LM protocol and logical link control and adaptation protocol (L2CAP,·104·all of which are fully defined in subsequent parts of the Bluetooth specification.译文:蓝牙核心系统协议包括射频

44、协议、链路控制协议、连接管理协议、逻辑链路控制应用协议,所有这些协议都是由蓝牙规范定义的。(1 LC: Link Control链路控制,链接控制器管理对其他蓝牙设备的链接。它是个低层的基带协议管理者。(2 LM: Link Manager 链路管理,链路管理软件实体负责管理建立链接、鉴定、链路配置,以及实现其他协议等事务。(3 L2CAP: Logical Link Control and Adaptation Protocol 逻辑信道控制和适配协议。该协议支持高层协议多路复用技术,包括分割和重组装技术,以及保证传达服务信息的质量。6. There are device control s

45、ervices that modify the behavior and modes of a Bluetooth device, transport control services that create, modify and release traffic bearers (channels and links, and data services that are used to submit data for transmission over traffic bearers.译文:设备控制服务用于改善蓝牙设备的性能和模式,传输控制服务用于创建、修改、释放(信道和链路上的承载业务,

46、数据服务则为基于承载业务的传输提供数据。7. Although these assumptions may not be required for embedded Bluetooth technology implementations that combine all layers in a single system, the general architectural and QoS models are defined with these assumptions in mind, in effect a lowest common denominator.译文:对于将所有层都组合成

47、一个单一系统的嵌入式蓝牙设备来说,这样的假设是不需要的,但是,简单结构的系统以及QoS模型的定义都是在考虑这些假设的前提下确定的,而且这样的系统更具有普遍性。QoS: Quality of Service 服务质量。8. The technology is now available in its fourth version of the specification and continues to develop, building on its inherent strengths small-form factor radio, low power, low cost, built-i

48、n security, robustness, ease-of-use, and ad hoc networking abilities.译文:第四版的蓝牙规范已经定义了该技术,鉴于其与生俱来的优点,诸如小尺寸、低功耗、低价格、高安全、强生命力、操作简单、具备ad hoc网络能力等,该技术发展前景广阔。9. PIN:Personal Identification Number个人识别码。蓝牙中的PIN用来鉴定以前没有交换过链接关键字(link key的两个设备。通过交换PIN,设备之间就创建了相互信任的关系。在配对(pairing过程中使用的PIN用来生成初始链接,以便进一步的鉴定。Exerc

49、isesI. Translating the following English sentences into Chinese1. Bluetooth SIG members are busy developing headsets, mobile phones, cars, and computers with the technology integrated, and many more are also bringing new ideas to life by implementing Bluetooth technology in new use cases and astound

50、ing the world with their new designs.2. Bluetooth enabled hands-free systems in automobiles allow drivers to make calls directly through the speaker systems while keeping their Bluetooth mobile phone anywhere in the vehicle, both hands on the wheel, and both eyes on the road.·105·3. Symant

51、ec said the latest worm attempts to use Bluetooth connections to spread by searching for other Bluetooth-using devices that will accept requests for a connection when the computer is restarted.4. The link controller is responsible for the encoding and decoding of Bluetooth packets from the data payl

52、oad and parameters related to the physical channel, logical transport and logical link.5. These QoS settings may be used to indicate, for example, that the data is isochronous and therefore has a limited lifetime after which it becomes invalid, that the data should be delivered within a given time p

53、eriod, or that the data is reliable and should be delivered without error, however long this takes.II. Translating the following Chinese sentences into English1. 有了蓝牙技术,存储于手机中的信息可以在电视机上显示出来,也可以将其中的声音信息数据进行转换,以便在个人计算机上聆听。2. 蓝牙技术的传输速率设计为1MHz,以时分方式进行全双工通信,其基带协议是电路交换和分组交换的组合。3. 透过芯片上的无线接收器,配有蓝牙技术的电子产品能够

54、在十公尺的距离内彼此相通,传输速度可以达到每秒钟1兆字节。4. 蓝牙,是1998年推出的一种新的无线传输方式,实际上就是取代数据电缆的短距离无线通信技术,通过低带宽电波实现点对点,或点对多点连接之间的信息交流。5. 红外传输是一种点对点的传输方式,无线,不能离的太远,要对准方向,且中间不能有障碍物,也就是不能穿墙而过,几乎无法控制信息传输的进度。Text B: “Chinese standard” aims at international marketIn 2004, the TD-SCDMA standards for the 3-generation (3G mobile communi

55、cations network initiated by China and ratified by the International Telecommunication Union, has become a focus of the global telecom industry, reported People Daily. Both telecom operators and telecom equipment manufacturers have paid growing attentions to the "Chinese standard" for 3G.

56、Almost all-mobile communication equipment suppliers in the world are putting more investment and efforts in R&D for the "Chinese standard".The Chinese government has been making efforts to push forward the "Chinese standard" since the beginning of the year with the pace of R&

57、amp;D and industrialization becoming apparently quickened. The signing of supply contract for the field test of 3G and emergence of TD-SCDMA cellular phone are proof of such progresses.Technical advantages of the Chinese standard gradually come to showIn response to the questions for the so-called l

58、evel problems of the "Chinese standard", Zhang Xinsheng, Vice Director of Science and Technology Department, Ministry of Information Industry is of opinion that the underlying reason for having drawn the worlds attention so far lies·106·in the technological advantages of the TD-S

59、CDMA.The world mobile communication industry unanimously agrees that TD-SCDMA can serve as one of the standards for 3G after intensive researches and discussions on it. The TD-SCDMA is more extensively recognized following the auction of 3G frequencies in Europe.At present, the “Chinese standard” for 3G has become a highlight of the world. Japan, Europe and US are all paying attention to it. Each and every major telecom corporation in the world is doing research related to the "Chinese standard". The TD-SCDMA has