GSM简介毕业论文外文翻译.doc
《GSM简介毕业论文外文翻译.doc》由会员分享,可在线阅读,更多相关《GSM简介毕业论文外文翻译.doc(12页珍藏版)》请在三一办公上搜索。
1、英文资料原文INTRODUCTION OF GSM一、 GSM implicationThe GSM full name is: Global System for Mobile Communications, Chinese as the whole world two-way charges for cellular phones system, the popular name the whole world passes, is one kind stems from Europes mobile communication technical standard, is the sec
2、ond generation of mobile communication technology, its development goal is enables the world to be possible to use a mobile phone network standard together, lets the user use a handset to be able good the whole world. Our country used this technical standard in the early-1990s introduction, before t
3、his uses the honeycomb simulation migration technology, namely the first generation of GSM technology (on December 31, 2001 our country has closed simulation migration network). At present, China moves, China Unicom to have a GSM net respectively, for world biggest mobile communication network. GSM
4、system including GSM 900:900 MHz, GSM1800:1800MHz and GSM1900:1900MHz and so on several frequency bands. GSM (whole world mobile communication system) is one kind widely applies in European and the world other place numeric move telephone system. What GSM use is the time division multiple access ano
5、malous form, and it is the present three kind of digital cordless phones technology (TDMA, GSM and CDMA) uses the most widespread one kind. GSM digitizes the material, and carries on the data the compression, then transmits together with other two user data stream from the channel, other two user da
6、ta stream has the respective time slot. GSM in fact is Europes radio telephone standard, Joint board reported according to GSM the MOU, GSM has 1,200,000,000 users in the whole world, and the user proliferates more than 120 countries. Because many GSM network operator has the roaming agreement with
7、other overseas operators, therefore works as user after other countries, still might continue to use their mobile phone.An American Famous Correspondence Company Sprint Auxiliary unit, the American person-to-person communication is using GSM to take one kind of wide band person-to-person communicati
8、on service the technology. This kind of person-to-person communication service finally for Ericsson, Motorola as well as Nokia the handset which produces is establishing more than 400 base depots now. Handset includes telephone, short note beeper and intercom.GSM and other technologies are the wirel
9、ess mobile communication evolutions, wireless mobile communication including high-speed circuit exchange data, general packet radio system, based on GSM network data enlargement mode mobile communication technology as well as general mobile communication service.二、 GSM histories In 1998, the goal re
10、placed GSM for the making the third generation mobile phone (3G) the standard 3GPP start. 3GPP also accepted has maintained and continues to develop the GSM standard the work. ETSI is one of 3GPP members. In the development process, the GSM systems function obtains unceasingly richly. It can thus pr
11、ovide a diverse service. The short information service which first introduces by the GSM system (SMS) has provided one kind novel, convenient, the inexpensive communication way. In 1994, GSM has realized based on the circuit switching data traffic and the facsimile service. In 1999, the WAP agreemen
12、t caused the user to be possible through the handset visit Internet. After 2000, starts the commercial general grouping wireless service (GPRS) to enable the GSM system to be able to provide the data communication by the efficiency higher packet mode. In 2003, the EDGE technology started commercial,
13、 has provided the close 3G data communication ability. At present, the 3GPP organization is also developing the GSM standard, with the aim of using already massively deployed the GSM infrastructure, smoothly to 3G technology evolution.三、 GSM characteristics 1. GSM uses the direct-viewing characteris
14、tic: The GSM system has several important characteristics: Security beats ability to be good, the network capacity is big, the handset number fruitful in resources, the telephone conversation are clear, the stability not easily is disturbed, the information to be keen, the telephone conversation dea
15、d angle are few, the handset power consumption is low.2. GSM technical Characteristic:1. Frequency spectrum efficiency. Because used the highly effective modulator, the channel coding, to interweave, balanced and the speech coding technology, enabled the system to have the high-frequency spectrum ef
16、ficiency. 2. Capacity. Because each channel transmission band width increases, causes the frequency multiplying to plant does reduces compared to the request to 9dB, therefore the GSM systems frequency multiplying pattern may reduce to 4/12 or 3/9 even is small (analogous system is 7/21); In additio
17、n the half speed rate voice codes introduction and the automatic traffic distribution reduce the skip zone cut the number of times, causes the GSM systems volumetric efficiency (each megacycle each plot channel number) compared to TACS system high 35 times.3. Voice quality.In view of the fact that i
18、n digital transmission technology characteristic as well as GSM standard related space connector and voice code definition, when threshold value, the voice quality always achieves the same level, but has nothing to do with the wireless transmission quality.4. Opening connection. The GSM standard pro
19、vides open connection, is not only restricted in the space connector, moreover the publication network is direct as well as in network between equipment entity, for example A connection and Abis connection.5. Security.Through the authentication, the encryption and the TMSI numbers use, serves the sa
20、fe purpose. The authentication uses for to confirm the user to enter the net right. The encryption uses in the space connector, by the SIM card and network AUC key decision. TMSI is one by the service network the temporary identification number which assigns to the user, prevents some people to trac
21、k divulges its geographical position.6. Realizes roaming in the SIM card foundation. Roaming is the mobile communication key character, it symbolizes that the user may enter another network automatically from a network. The GSM system may provide global roaming, certainly also needs the network oper
22、ation between certain agreements, for example cost. 四、 GSM principle GSM is the Global System for Mobile Communication abbreviation. The meaning is the whole world mobile communication system. Divides GSM900, DCS1800 and PCS1900SAN a frequency band, the common so-called dual-frequency handset is in
23、GSM900 and the DCS1800 frequency band cut handset. PCS1900 (PCS1900 - Personal Communications System operating in the 1,900MHz band.) is other national use frequency band (for example the US). GSM900/1800 respectively is the work in the 890960mhz/17101880MHz frequency band. The GSM900 handset maximu
24、m work rate is 8W (actual traveling carriage not such big power, common handset maximum work rate is 2W, Che Zaitai the function big), but the DCS1800 handsets maximum work rate is 1W.GSM900/DCS1800/PCS1900 difference: GSM900 is the initial GSM system, the MOBILE power from outputs 1W8W, the GSM900
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- GSM简介 毕业论文外文翻译 GSM 简介 毕业论文 外文 翻译
链接地址:https://www.31ppt.com/p-4135730.html