《IPTV》实验指导书（模板）.docx

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1、实验三IPTV一、实验目的1、扩大通信技术的英语词汇量。2、熟悉通信行业、广播电视、可视 等专业术语。3、了解科技文章的表达特点和掌握科技英语的翻译技巧二、实验内容文章翻译IPTVOver the past few months, there has been increased interest in the use of IP networks to deliver broadcast-quality TV. IPTV is a relatively recent buzzword having emerged only three or four years ago. In a nuts

2、hell, it means the delivery of television over Internet Protocol (IP) networks. But for the telecommunication industry, which drives it to the market, IPTV means much more. For them, IPTV is an entirely new multimedia experience extending the borders of conventional broadcast television; it is an in

3、tegrated, all-embracingv media platform offering a bundle of diverse content and communication services from a single provider over a single network to a single user deviceall with a single payment. Why use 30-year-oldtechnology designed for slow, unreliable, unicast communications to transport vide

4、o? The answer is that IP is a magical platform to breed success and it has become totally pervasive. The second motivation is that IP can offer more functionality than traditional TV. The open, extensible nature of IP holds the promise of many more services in the future. IP infrastructure also can

5、be leveraged to provide video telephony and remote monitoring, as well as new uses of video within applications that haven t been thought of yet. The final factor that is emerging is cost savings.There are diverging views about what IPTV really means. To broadcasters, IPTV is simply a new emerging p

6、latform for distributing digital television channels to home consumers using a TV screen. To the telecom industry, IPTV is synonymous with a new broadband digital technology, offering voice, data and video. IPTV is complementary to existing satellite, cable and terrestrial systems, although in some

7、cases it may become a vigorous competitor to them.softswitcha programmable device that controls Voice over IP calls. Itenables correct integration of different protocols within NGN. The most important function of the softswitch is creating the interface to the existing telephone network, PSTN, throu

8、gh signaling Gateways (SG) and Media Gateway (MG). However, the softswitch as a term may be defined differently by the different equipment manufacturers and have somewhat different functions. A Signaling Gateway is a network component solely responsible for translating signaling messages (i.e. infor

9、mation about call establishment and teardown) between one medium (usually IP) and another (PSTN). For example, a signaling gateway might translate between I SUP and SIP. A Media Gateway acts as a translation unit between disparate t e 1 ecommun i cat ions networks such as PSTN, Next Generation, 2G a

10、nd 3G, radio access networks or PBX. Media Gateways enable multimedia communications across Next Generation Network over multiple transport protocols such as ATM and IP. Because the MG connects different types of networks, one of its main functions is to convert between the different transmission an

11、d coding techniques.The market for telecommunications services in the world has developed extremely dynamically since being liberalized. However, a weakening of the average annual growth on the various markets is to be expected by the end of the decade. The business with broadband connections is bei

12、ng treated as particularly lucrative in order to compensate for the market-share losses of the fixed network in particular. The network operators are attempting to provide a more efficient and cost-effective provision of services with the current conversion of the entire network infrastructure to IP

13、 technology. The aim is to unit fixed, mobile and data networks together and so to provide various services via a transparent networkthe so calledNetwork Generation Network.三、实验步骤及要求1、首先，翻开手机，在应用市场上搜索可以翻译文档的软件，然后将翻译软 件先下载手机匕 然后翻开软件。软件分为三个功能：文档翻译、图片翻译、短句翻译。2、将翻译软件中的翻译参数设置为英译汉，将需要翻译成的语言调整为简体 中文。3、利用翻译

14、软件功能，采用一句原文，一句中文的方式进行翻译。4、将翻译后的汉语内容进行适当的句式调整施I准确、完整、通顺和专业。四、实验设备一部可以装有翻译软件的智能手机。五、实验预习要求阅读实验指导书内容，做好课前预习工作。六、实验报告要求要求对文章进行翻译，书写的翻译内容要通顺、专业。So far, the telecom industry has merely been providing telecommunication services such as voice connections between two points. The telecom companies were not at

15、 all concerned with the content of the information carried. They are now getting involved in IPTV as they facing decreasing subscriber revenues from their traditional voice and broadband communication. They are in the process of moving into the content-providing domain with no real expertise and exp

16、erience in providing television services to the general public, simply in order to improve their balance sheet and bring the customers back. Indeed, IPTV is beginning to look like a promising new business opportunity for telecom operators.However, telecoms will have to resolve some major technical c

17、hallenges. One problem is the end-to-end transmission quality due to limited network bandwidth which decreases with the distance from the exchange cabinet. New modulation strategies such as ADSL2+ and VDSL are being introduced, but the cost concerned is relatively high. The introduction of High-Defi

18、nition Television (HDTV) may be quite a challenge, even if advanced coding technologies such as ITU/MPEG 4 or Microsoft VC1 are used. Furthermore, Telecom networks do not generally serve the hundreds of thousands and even millions of simultaneous users. A lack of international standardization, which

19、 is currently the main obstacle to establishing horizontal markets and equipment inter-operability, is now being addressed by the International Telecommunications Union.IPTV can potentially offer a myriad of new innovative services and applications to the user, many of which are already possible wit

20、h digital television. The main differences come from the fact that IPTV uses a two-way communication channel, so the user can interact directly with the content and service provider. The interactive link between the provider and the user enables sending individual video streams to individual devices

21、 in the home at the user s request, in contrast to the broadcast model where all channels are sent to all users all the time. Such personalized services are becoming increasingly popular, particularly with entertainment and education.While the technical issues are not easy, they are not insurmountab

22、le. The legal and regulatory issues, however, are a real nightmare. One of the outstanding issues is to determine which national regulatory body is responsible for the regulation of IPTV services. This depends on the very definition of IPTV. Some countries consider IPTV a broadcast service and some

23、a telecom service. Not only do the legal regimes vary from country to country, they are also different for telecoms and broadcasters.IPTV is still in its infancy. Its market size is still small but it is growing rapidly. The prospects for the commercial success are great. The principle drivers for I

24、PTV are the incumbent telecom and Internet companies. So far, broadcasters have been marginally involved in the IPTV process. It is now time to raise the awareness of broadcasters, so that they can play a more active role in the IPTV developments.三、实验步骤及要求1、首先，翻开手机，在应用市场上搜索可以翻译文档的软件，然后将翻译软 件先下载到手机匕

25、然后翻开软件。软件分为三个功能：文档翻译、图片翻译、短句翻译。2、将翻译软件中的翻译参数设置为英译汉，将需要翻译成的语言调整为简体 中文。3、利用翻译软件功能，采用一句原文，一句中文的方式进行翻译。4、将翻译后的汉语内容进行适当的句式调整做角、完整、通顺和专业。四、实验设备一部可以装有翻译软件的智能手机。五、实验预习要求阅读实验指导书内容，做好课前预习工作。六、实验报告要求要求对文章进行翻译，书写的翻译内容要通顺、专业。实验四 Current S i tuat i on and the Future i n theTelecommunicat ion WorId-、实验目的1、扩大通信技术的英

26、语词汇量。2、熟悉电电视信号、无线电波等专业术语。3、了解科技文章的表达特点和掌握科技英语的翻译技巧。二、实验内容文章翻译Current Situation and the Future in the Telecommunication WorldTodays telecommunication networks are characterized by specialization. This means that for every individual telecommunication service at least one network exists that transport

27、s this service. A few examples of existing public networks are described below: The telex network transports telex information, i. e. messages of characters, transported at very low speed. The characters are coded based on a specific 5-bit code. POTS (plain old telephone service) is transported via

28、the public switched telephone network (PSTN). This ubiquitous network offers the customers classical two-way voice conversation. Computer data are transported in the public domain either by a packet switched data network based on X. 25 protocols or in a very limited number of countries by a circuit

29、switched data network based on X. 21 protocols. Television signals can be transported in three ways: broadcast via radio waves using ground antenna, by the coaxial tree network of community antenna TV network or recently via a satellite, using the so-called direct broadcast system. In the private do

30、main, computer data are mainly transported by LANs (Local Area Network). The most famous ones are Ethernet, token bus and token ring (IEEE 802 series).Each of these networks was specially designed for that specific service and is often not at all applicable to transport another service. For instance

31、, the original CATV networks did not allow the transportation of POTS; or the PSTN does not transport TV signals; or the transfer of voice over an X. 25 network is very problematic because of too large end-to-end delay and jitter on this delay.Only in limited and special cases can service types othe

32、r than the one the network was originally designed for be transported over it. This is for instance the case for the PSTN which is capable of transporting computer data at a limited speed, if modems are provided at both ends of the network.An important consequence of this service specialization is t

33、he existence of a large number of often world-wide independent networks, each requiring its own design phase, manufacturing and maintenance. In addition, the dimensioning of each network must be done for every individual service type. Even if resources are freely available in one network, they canno

34、t be used by another service type. For example, the peak hours in the telephone network are between 9 a. m. and 5 p. m., whereas the peak hours in the CATV network are during evening. Since resource pooling is impossible each network must be dimensioned for its worst case traffic conditions which is

35、 the peak hour traffic.A first step, albeit a limited one towards a single universal network, is the introduction of NISDN in which voice and data are transported over a single medium. This network cannot transport TV signals due to its limited bandwidth capabilities, so a special TV network is stil

36、l required. Even inNISDN the integration of narrowband services such as data and voice can be considered as being rather limited: the user access to the network is fully integrated, either by a basic access or primary rate interface. However, inside the network there will still exist for some time a

37、 packet switched and a circuit switched network as two overlay networks incapable of transporting other traffic types and each dimensioned either for voice or X. 25 data.Another important consequence of this service specialization is the inability of the network to benefit highly from the progress m

38、ade in technology and coding algorithms. For instance, current digital NISDN switches are designed for 64 kbit/s voice channels. However, with the current progress in speech coding and chip technology, bit rates of 32 kbit/s, 13 kbit/s and even lower will be used in the future. The existing switches

39、 and transmission systems are not directly suited and thus need an adaptation, or will not efficiently use their internal resources for these lower speed bit rates.When designing the future BISDN network, one must take into account all possible existing and future services. Suppose a network is capa

40、ble of transporting a specific service, e. g. a circuit switched service with a channel rate of 70 Mbit/s. Suppose also that it is specifically designed to transport this bit rate. Some years later a new teleservice of, for example, 40 Mbit/s appears on the scene. This would mean that the network de

41、signed for that service (i. e. 70 Mbit/s) will be capable of transporting the new teleservice, but with a large inefficiency: only 40 out of the 70 Mbit/s available will be used. This example is not unrealistic. It is very likely that in the future new services will emerge which have not yet been id

42、entified, and of which the requirements are unknown today.As can be concluded from the above examples, the networks of today are very specialized and suffer from a large number of disadvantages, the most important being: Service DependenceEach network is only capable of transporting one specific ser

43、vice for which it was intentionally designed. Only in a limited number of cases and by using additional equipment (e. g. a modem) and with an inefficient use of its resources can it be adapted to other services. InflexibilityAdvances in audio, video and speech coding and compression algorithms and p

44、rogress in Very Large Systems Integration (VLSI) technology influence the bit rate generated by a certain service and thus change the service requirements for the network. In the future, new services with unknown requirements will appear. For the time being it is yet unclear, e. g. what the requirem

45、ents in terms of bit rate for HDTV will be. A specialized network has great difficulties in adapting to changing or new service requirements. InefficiencyThe internal available resources are used inefficiently. Resources which are available in one network cannot be made available to other networks.T

46、aking into account all these considerations on flexibility, service dependence and resource usage, it is consequently very important in the future that only a single network exists and that this network of the future (BISDN) is service-independent. This implies a single network capable of transporti

47、ng all services, sharing all its available resources between the different services.A single service-independent network will not suffer from the disadvantages described above, but it will have the following main advantages: Flexible and future-safeAdvances in the state of the art of coding algorith

48、ms and VLSI technology may reduce the bandwidth of existing teleservices. A network capable of transporting all types of services will be able to adapt itself to changing or new needs. Efficient in the use of its available resourcesAll available resources can be shared between all services, such tha

49、t an optimal statistical sharing of the resources can be obtained. Less expensiveSince only one network needs to be designed, manufactured and maintained, the overall costs of the design, manufacturing, operations and maintenance will be smaller.三、实验步骤及要求1、首先，翻开手机，在应用市场上搜索可以翻译文档的软件，然后将翻译软 件先下载手机上 然后翻开软件。软件分为三个功能：文档翻译、图片翻译、短句翻译。2、将翻译软件中的翻译参数设置为英译汉，将需要翻译成的语言调整为简体 中文。3、利用翻译软件功能，采用一句原文，一句中文的方式进行翻译。4、将翻译后的汉语内容进行适当的句式调整施唯解完整、通顺和专业。