ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments

pdf标准 ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments

5 页 0 下载 0 浏览 0 评论 0 收藏 3.0分
温馨提示:当前标准最多只能预览 10 页,若标准超出了 10 页,请下载原标准以浏览全部内容。
ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments  第 1 页 ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments  第 2 页 ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments  第 3 页 ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments  第 4 页 ITU-T G.602-1988 模拟电缆传输系统及其相关设备的可靠性和可用性 Reliability and availability of analogue cable transmission systems and associated equipments  第 5 页
本标准由 5zbz2018-09-16 14:46:07上传分享

国外分类,ITU,ITU-T(电信标准分局),itu,模拟,电缆,传输,系统,及其,相关,设备,可靠,可靠性,可用,可用性,reliability,and,availability,of,analogue,cable,transmission,systems,and,associated,equipments

INTERNATIONAL TELECOMMUNICATION UNION )45 4 ' TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU 42!.3-)33)/. -%$)! #(!2!#4%2)34)#3 2%,)!"),)49 !.$ !6!),!"),)49 /& !.!,/'5% #!",% 42!.3-)33)/. 3934%-3 !.$ !33/#)!4%$ %15)0-%.43 )45 4 Recommendation ' (Extract from the "LUE "OOK) NOTES 1 ITU-T Recommendation G.602 was published in Fascicle III.3 of the Blue Book. This file is an extract from the Blue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, the contents of the file are identical to the Blue Book version and copyright conditions remain unchanged (see below). 2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. © ITU 1988, 1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the ITU. Recommendation G.602 Fascicle III.3 - Rec. G.602 RELIABILITY AND AVAILABILITY OF ANALOGUE CABLE TRANSMISSION SYSTEMS AND ASSOCIATED EQUIPMENTS (Malaga-Torremolinos, 1984) 1 General section Transmission system: all that is necessary in order to provide an adequately operational transmission path (e.g. 4 kHz channel) between the terminating interfaces. It includes translating equipment, line terminal equipment, line intermediate equipment, cable, power feeding, primary power and standby power supplies and might also include the changeover equipment when automatic protection switching is provided. 2 Definitions a) reliability in analogue cable transmission systems The reliability of a single unit of an analogue transmission equipment or of a complete transmission system is defined as the probability that this item can perform its required function for a given time interval. One parameter to quantify this reliability is the mean time between failures (MTBF). A failure of the system is considered to occur when there is: 1) complete loss of signal; 2) one in which the pilot level drops by 10 dB below nominal value; 3) when the total unweighted noise power, measured or calculated with an integrating time of 5 ms exceeds 1 million pW (106 pW) on the 2500 km hypothetical reference circuit (see Recommendation G.222). In all instances, this condition must last at least 101) seconds. b) availability in analogue cable transmission systems The availability of an analogue transmission system is defined as the ability of the system to be in a state to perform adequately (operating) at a given instant of time or at any instant of time within a given time interval. In this Recommendation, the availability of an analogue transmission system is quantified by the ratio of the time during which the system is operating to a specified total time. Four factors influencing availability are: - reliability of the equipment; - automatic protection switching; - maintenance procedures; - cable routing and protection. In considering the importance to be attached to the individual factors, economic aspects should play an important role. Note - Experience has shown that in many cases the cable faults are dominating (in the order of 95% of the unavailability time) over the equipment faults and that the length of the line section and the kind of route (running along roads with heavy traffic, etc.) have a decisive influence on the achievable availability values. _______________ 1) This value should be considered as being provisional. Fascicle III.3 - Rec. G.602 1 3 Objectives a) Reliability As indicated in the definition of availability, reliability is but one of the factors involved in obtaining an availability objective. Therefore, no specific objective for reliability is recommended. b) Availability 1) Hypothetical reference circuit (2500 km) The objective for the availability of a 2500 km hypothetical reference circuit in one direction should be greater than 99.6% for a one year duration. This takes into account outages for both translating and line equipment and the cable and associated powering equipments. To achieve this objective, appropriate protection switching may be required. 2) Translating equipment The design objective for the availability of translating equipment in the Annex and in Figure A1/G.602, for a 2500 km hypothetical reference circuit as recommended for the different transmission systems, should be greater than 99.9% measured for a period of one year for one direction of transmission. 3) Line section The design objective for the availability of a 280 km homogeneous section for one direction shall be derived from the overall requirement for the hypothetical refer

给标准打分
您好可以输入 255 个字符
本站的中文名字叫什么( 答案:找标准 )
评论列表
  • 暂时还没有评论,期待您的金玉良言