欢迎来到麦多课文档分享! | 帮助中心 海量文档,免费浏览,给你所需,享你所想!
麦多课文档分享
全部分类
  • 标准规范>
  • 教学课件>
  • 考试资料>
  • 办公文档>
  • 学术论文>
  • 行业资料>
  • 易语言源码>
  • ImageVerifierCode 换一换
    首页 麦多课文档分享 > 资源分类 > PDF文档下载
    分享到微信 分享到微博 分享到QQ空间

    ITU-R S 521-4-2000 Hypothetical Reference Digital Paths for Systems Using Digital Transmission in the Fixed-Satellite Service《使用15GHz以下频率的静止轨道卫星系统固定卫星业务中用于B-ISDN异步传输模式传输的假设参考数字》.pdf

    • 资源ID:793632       资源大小:192.49KB        全文页数:5页
    • 资源格式: PDF        下载积分:10000积分
    快捷下载 游客一键下载
    账号登录下载
    微信登录下载
    二维码
    微信扫一扫登录
    下载资源需要10000积分(如需开发票,请勿充值!)
    邮箱/手机:
    温馨提示:
    如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
    如需开发票,请勿充值!如填写123,账号就是123,密码也是123。
    支付方式: 支付宝扫码支付    微信扫码支付   
    验证码:   换一换

    加入VIP,交流精品资源
     
    账号:
    密码:
    验证码:   换一换
      忘记密码?
        
    友情提示
    2、PDF文件下载后,可能会被浏览器默认打开,此种情况可以点击浏览器菜单,保存网页到桌面,就可以正常下载了。
    3、本站不支持迅雷下载,请使用电脑自带的IE浏览器,或者360浏览器、谷歌浏览器下载即可。
    4、本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰。
    5、试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。

    ITU-R S 521-4-2000 Hypothetical Reference Digital Paths for Systems Using Digital Transmission in the Fixed-Satellite Service《使用15GHz以下频率的静止轨道卫星系统固定卫星业务中用于B-ISDN异步传输模式传输的假设参考数字》.pdf

    1、Rec. ITU-R S.521-4 RECOMMENDATION ITU-R S .52 1-4 HYPOTHETICAL REFERENCE DIGITAL PATHS FOR SYSTEMS USING DIGITAL TRANSMISSION IN THE FIXED-SATELLITE SERVICE 1 (1978-1982-1986-1997-2000) The ITU Radiocommunication Assembly, considering a) afford guidance to designers of equipment and systems for use

    2、in networks employing digital transmission techniques; b) cl d) - on-board processing with regeneration, - e) that the transmission delay variation introduced by satellite movement is of significance in some applications but the buildout of such delay variations to their worst case to provide consta

    3、nt delay is outside the scope of this Recommendation: that it is desirable to establish hypothetical reference digital paths (HRDPs) for active fixed-satellite systems to that satellite-to-satellite links may be used in the fixed-satellite service (FSS); that both geostationary and non-geostationary

    4、-satellite systems will be part of the FSS; that some satellite systems include: on-board processing with regeneration and switching on the satellite; f) that a FSS HRDP may form part of a hypothetical reference connection (HRX) as defined by ITU-T Recommendation G.801, Fig. 1; g) contiguous portion

    5、s of a HRX; h) single HRX; j) k) that satellite links may appear in the local, national, or international portion and combinations of two or more that inter-satellite links (ISLs) among geostationary satellites and non-geostationary satellites may be part of a that a HRDP may include one or more int

    6、ermediate space-to-Earth and Earth-to-space segments; that a HRDP may be independent of connections to the terrestrial network, recommends 1 connected to terrestrial networks; 2 portion may comprise one or more ISL; 3 more than one satellite, but in each case there may be only one satellite; 4 consi

    7、dered as part of the terrestrial network and should not be included in the HRDP; 5 equipment necessary for connecting the diversity earth stations to the diversity switching point; that a generic HRDP shown in Fig. 1 should be used to describe satellite connections which may or may not be that a HRD

    8、P for systems in the FSS should consist of one or more Earth-space-Earth links, whose space that the example HRDPs shown in Annex 1 can be used to describe satellite connections. These Figures show that links between the earth stations and their associated terrestrial digital switching centres shoul

    9、d be that for site diversity earth stations, the HRDP should also include the terrestrial links and any associated 6 demultiplex equipment at the customer terminal or earth station; 7 that the HRDP includes RFDF, demodulation/modulation, error correction, buffer, processing, and multiplex/ that term

    10、inal equipment or switch nodes may interface a HRDP at any bit rate. 2 Rec. ITU-R S.521-4 FIGURE 1 Generic HRDP UNI, NNI or equivalent Satellite link UNI, NNI or equivalent switch node c El station El station 4: switch node SAT: space stations in the FSS, or space station in the service interconnect

    11、ed by satellite-to-satellite links NNI: network-node interface UNI: user-network interface TE: terminal equipment 052 1-01 NOTE 1 - For satellite networks where earth station processing is integrated with dynamic allocation and rearrangement of capacity across the satellite link, the equipment to pe

    12、rform that processing should be regarded as part of the satellite HRDP. This processing may also include functions for: - - performance improvement, - NOTE 2 - Customer terminal equipment which would be required to support the particular service(s) being offered regardless of the transmission medium

    13、 it is connected to is assumed to be outside the satellite HRDP. NOTE 3 - The HRDP considered in this Recommendation applies to public networks only. Network operators may use these HRDPs for their private networks. NOTE 4 - The HRDP in this Recommendation is not limited to point-to-point services b

    14、ut may be used for multipoint and asymmetric services. NOTE 5 - The need for additional HRDP examples to encompass the range of new digital satellite systems is for further study. NOTE 6 - This Recommendation does not address allocation of performance objectives to the HRDPs. It is recognized howeve

    15、r that the same HRDP may be used to represent different satellite system configurations (e.g. on-board processing, earth station processing, non-processing transponder, ISL) which may require different performance allocations. NOTE 7 - This Recommendation does not apply for end-to-end links in the B

    16、SS. efficient use of satellite bandwidth, service capabilities peculiar to the satellite system. ANNEX 1 The example HRDPs shown in Figs. 2 to 6 can be used to describe satellite connections. These Figures show more than one satellite, but in each case there may be only one satellite. The terminolog

    17、ies used in the Figures are shown below: - UNI: user-network interface; - NNI: network-node interface; 3 r TE Rec. ITU-R S.521-4 - SAT: satellite station (including on-board processing/switching if used); - Earth station includes RFDF, modulation/demodulation, error correction, buffer, processing, m

    18、ultipleddemultiplex equipment and interfaces to terrestrial networks. Figure 2 describes a HRDP which may be in the national or international portion of a HRX, with connections to the TE: terminal equipment (including processing, multiplex equipment, interfaces to earth station). Earth Earth Local s

    19、tation station switch node r terrestrial network at both ends. FIGURE 2 Satellite HRDP (with connections to the terrestrial network of both ends) Figures 3 and 4 describe HRDPs which form part of a HRX, with connection to the terrestrial network. It includes a local portion to the customer terminal.

    20、 The HRDP may be in the domestic or international portion. FIGURE 3 Satellite HRDP (with connection to the terrestrial network at one end) 0521-03 4 Rec. ITU-R S.521-4 FIGURE 4 Satellite HRDP ent Switch node station *SAT includes on-board processing/switching. a) With connection to the terrestrial n

    21、etwork at one end, and with on-board processing/switching satellite UNI UNI orNNI / switch node I I “I station I czF /Rrrihl station or NNI switch node b) Including control path 052 1-04 Figure 4b) describes a HRDP including a control path associated with a control earth station that is part of the

    22、satellite network. Rec. 1TU-R S.521-4 Figure 5 describes a HRDP which does not connect to the terrestrial network. FIGURE 5 Satellite HRDP (no connection to the terrestrial network) 5 052145 Figure 6 describes a HRDP which includes a space-to-Earth and an Earth-to-space link to an intermediate earth station for further processing, but the HRDP does not connect to the terrestrial network. FIGURE 6 Satellite HRDP (with intermediate earth station) I 0521-06


    注意事项

    本文(ITU-R S 521-4-2000 Hypothetical Reference Digital Paths for Systems Using Digital Transmission in the Fixed-Satellite Service《使用15GHz以下频率的静止轨道卫星系统固定卫星业务中用于B-ISDN异步传输模式传输的假设参考数字》.pdf)为本站会员(cleanass300)主动上传,麦多课文档分享仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文档分享(点击联系客服),我们立即给予删除!




    关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服 - 联系我们

    copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
    备案/许可证编号:苏ICP备17064731号-1 

    收起
    展开