ITU-T E 175-1993 Models for International Network Planning《国际网规划模型》.pdf

1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 % TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%0(/.%G0G0.%47/2+G0G0!.$G0G0)3$./0%2!4)/. G0G0.5-“%2). G0G02/54).G0G0!.$G0G0-/“),%3%26)#%-/$%,3G0G0 type of computer model; study period; cost of capital; method of financial comparison (e.g. present value

2、); other economic parameters; types of input information required; form of results to be provided.Step II Gather required input informationThe interested parties should then obtain the input information agreed to in Step I for their respectiveAdministrations. This information could include items suc

3、h as: traffic forecasts (bilateral); administration preferences:a) routing,b) diversity,c) satellite/cable mix,d) restoration; ownership in existing facilities; facility exhaust dates; new facilities;a) capacity,b) costs,c) availability, quality of service requirements.Step III Route traffic on prop

4、osed networkIf a manual process is being used, the routing of traffic could then be performed by a study group selected bythe interested parties. These traffic loads on the various facilities in the network would then be used in the selection ofthe appropriate facilities (Step IV) that would either

5、be loaded (in the case of existing facilities), or that would have tobe constructed in the study period.In the case of a computer modelling process, the Steps III and IV could either be separate or merged, dependingon the model chosen.In either case of manual or computer processing, some iteration o

6、f Steps III and IV is usually required in theprocess, i.e., the loading of circuits on the various links of the network depends on the costs of these facilities, whilethe facilities selected (and therefore their costs) depend on the number of circuits loaded on them.Fascicle II.2 - Rec. E.175 3Step

7、IV Select new facilitiesThe selection process used by the study group should reflect the operational, technical and commercialrequirements of the interested parties. Facilities should be dimensioned so as to result in the lowest practical networkcost consistent with the preferences of the individual

8、 parties. Also (as stated in Step III) it is possible that the facilitieschosen could result in costings that could make the rerouting of circuits advantageous.Steps III and IV should be repeated as necessary to obtain consistent results between routing and facilityselection.Step V Allocate costs by

9、 potential participantsNetwork costs should then be broken down by potential participants. These costs should be broken into: capital costs by facility; maintenance costs by facility; extension costs; satellite space segment related costs.Special participant reports could be required as determined i

10、n Step I.Step VI Check results with potential participantsAt this point, the special study group should present results to the potential participants. If results are agreeableto this body, then the process could proceed. If, however, the results are not agreeable, then the process should return toSt

11、ep II to reflect the problems and concerns of the participants. It is possible that more than one alternative networksolution may be requested by the participants.Step VII Obtain agreement on final planIf the results in Step VI are agreeable to the potential participants, then the process can contin

12、ue to the signingof commitments for any new facilities required by the study.Step VIII Implement early period facilitiesThe process of providing the facilities required in the early part of the study period can then begin, leaving thenew construction required in the later study period for further re

13、consideration as conditions warrant.Step IX Restudy area as conditions warrantThe network plan should be restudied periodically as new information becomes available. This could includechanges in economic conditions, traffic forecasts, costs, new technologies, or political conditions.4 Fascicle II.2 - Rec. E.175