1、CEPT T/CS*bE-OL*E 2326434 000523b 9 Page 1 G9 T/CS62-01 E Recommendation T/CS 62-01 (Brussels 1980, modified in Vienna 1982, Montpellier 1984 and Odense 1986) INTRODUCTION, FIELD OF APPLICATION AND BASIC FUNCTIONS FOR DIGITAL LOCAL AND COMBINED EXCHANGES Recommendation proposed by Working Group T/WG
2、 1 1 “Switching and Signalling” (CS) “The European Conference of Postal and Telecommunications Administrations, considering that digital local and combined exchanges are currently being introduced for both analogue and digital telephone networks, - the evolution of telecommunication networks toward
3、an integrated services digital network (ISDN) with digital access of customers is expected in many countries, - CEPT Recommendations on digital local exchanges exist since 1980 and now CCITT Recommendations have been established in the same area, - the study of requirements for digital local switchi
4、ng systems will take into account developments of the ISDN and results will be reflected in the Recommendations, O recommends that the members of the CEPT when introducing digital local and combined exchanges, take account of and give effect to the following set of switching systems specifications.”
5、 Notes. - CCITT Recommendations take into account most of those ideas developed in the preceding CEPT Recommendations and the final versions established in CCITT are supported by CEPT member Administrations. - It is helpful for writers and readers of Recommendations on digital local and combined exc
6、hanges to have the information presented in a uniform way in the two sets of Recommendations to facilitate concentration on specific issues from the CEPT point of view and progress in areas not covered so far by CCITT; in order to limit as much as possible the redundancy, however, the present text h
7、as been reorganized with the aim of emphasizing the differences with respect to CCITT Recommendations. The reader is referred to CCITT Recommendation Q.511 i, to which this Recommendation is identical, except for the additions and modifications indicated below. The section references (indicated 0) a
8、re to Q.511 i. 5 1; the CEPT series of Recommendations is: T/CS 62-01 2 instead of Q.511 i T/CS 62-02 4 instead of Q.512 5 T/CS 62-03 6 instead of 4.513 7 T/CS 62-04 8 instead of 4.514 9 T/CS 62-06 lo instead of 4.516 12. Note. CCITT Recommendations Q.515 13 and Q.517 I41 are not considered. 0 3 ; a
9、dd at the beginning; The fundamental purpose of a digital local or combined exchange is circuit switching. The functions which may be required to fulfil this purpose are described in this Recommendation. There is no intent to describe hardware, software of firmware implementations, and no constraint
10、 on the design of the functions, either individually or collectively, is implied. In integrated services digital networks, some packet handling facilities and/or information processing functions might also be provided in the digital local or combined exchange. The general objectives of the exchange
11、are: - to set up and clear down connections controlled by signalling systems or control-initiated by man-machine - to perform as specified in Recommendations T/CS 62-02 4, T/CS 62-03 6, T/CS 62-04 XI and T/CS 62-06 lo; O communications; Edition of September 15, 1986 CEPT T/CS*bZ-OL*E M 2326434 00052
12、37 O - to work in harmony as a network element with other exchanges conforming to the T/CS 62 Group of Recommen- dations, with digital transit exchanges (see T/CS 68 Group of Recommendations: T/CS 68-01 15, 68-02 16, 68-03 17, 68-04 18, 68-06 i i) and with existing analogue exchanges; - to provide a
13、t least a specified minimum of operation, maintenance and diagnostic information as required for efficient operation (see Recommendation T/CS 62-06 1 O; - to be a component in the IDN and to put minimal constraint on the development of the ISDN; - to act as a node in the timing/synchronisation syste
14、m; - to work with the recommended CCITT, CEPT and other signalling system(s) as required because of its position Certain other objectives may be optional: - to control ancillary equipment; - to provide additional operation, maintenance and diagnostic information for efficient operation of the exchan
15、ge - to provide accounting and/or charging information; - to provide operator services; - to act as a timing/synchronisation source. The functional block diagram, Figure 1 (T/CS 62-01 2), is intended only as an aid to comprehension. It is not intentionally a representation of any specific exchange a
16、rchitecture and illustrates an abbreviated conceptual inter- connection of functions. The functional description does not differentiate between Co-located and remotely located arrangements. Arrange- ments, where, e.g. parts of the switch, or the maintenance, operation and diagnosis functions, or the
17、 control, are remotely located, are also covered by this Figure. 0 3.2.1; add at the end: Within the digital network pertaining to a local or combined exchange, the clock of the exchange may be responsible for maintaining the synchronisation in the local network including remote exchange concentrato
18、rs and muldexes. The exchange at the head of the synchronisation hierarchy may contain the national timing source or may be directly slaved from it. 4 3.2.2; add after the first sentence: For telephony, a path will have the external appearance of a bidirectional connection. Switching Switching is su
19、bdivided into concentration switching, internal switching and route switching according to the typical functions to be performed in the local exchange. The term concentration should be regarded from the functional point of view, e.g. the concentration of trafic (erlangs). It does not preclude the pr
20、esence of a special separate switching stage for this purpose. in the international or national network. and associated transmission, signalling, timing and ancillary equipment; a Edition of September 15, 1986 CEPT T/CS*bZ-OL*E i Synchronisation U Timing interface function Interface function Concent
21、ration Internal Route switch in g switching switching Subscnber access function and signalling Interexchange signalling Subscriber Ancillary services function functions D 2326434 0005238 2 Circuits to other exchanges TICS 62-01 E Page 3 Maintenance and operation Subscribe1 lines Figure 1 (T/CS 62-01
22、). Functional arrangement of a digital local or combined exchange. 8 3.2.3; replace by the following: The signalling function includes reception of call-related and other information, its translation into information for control and other functions, and transfer of information to subscribers and net
23、works, as required. It includes inter-exchange signalling, which is mainly related to the inter-exchange links and subscriber access function and signalling, related to the subscriber. The signalling function may involve common channel and/or channel associated signalling. 0 3.2.4; replace the last
24、paragraph by the following: Control includes generation of charging information, running diagnostic routines on its own and other functions, and generating traffic and maintenance statistics, if required. For simplicity, control is shown as a single block. The functions may be distributed throughout
25、 the exchange. 0 3.2.6; add a new section: Subscriber Services Functions Figure 1 (T/CS 62-01 2) is considered to be mainly relevant for telephony and similar services but it may also contain the functions necessary for other services. 5 3.4; add a reference to T/CS 54-12 19). Edition of September 1
26、5, 1986 CEPT T/CS*bZ-OL*E 232b414 0005239 4 T/CS 62-01 E Page 4 5 3.5; add at the end: See also Recommendation T/CS 50-01 3. These functions involve interfacing between exchanges and operating staff and/or operation and maintenance centres (OMCs). Included may be fault recording and diagnosis, provi
27、sion of man-machine communication, collection of information concerning the exchange and network operations (trafic measurement, network management), accounting, etc. 9 4; add a new section: 4 HARMONISATION The T/CS 62 Group of Recommendations aims to specify parameters as a basis for functional har
28、monisation. At present, these Recommendations are not suficiently detailed to give satisfactory answer to all questions concerning harmonisation. This requires further study. REFERENCES CCITT Recommendation Q.511. Introduction, jeld of application and basic functions. TICS 62-01 Recommendation. Intr
29、oduction,$eld of application and basic functions for digital local and combined exchanges. TICS 50-01 Recommendation. Maintenance philosophy for digital and mixed networks. T/CS 62-02 Recommendation. Interfaces for digital local and combined exchanges. CCITT Recommendation Q.5 12. Interfaces for dig
30、ital local and combined exchanges. TICS 62-03 Recommendation. Connections, signalling, control, call handling and ancillary functions for digital local and combined exchanges. CCITT Recommendation Q. 5 13. Connections, signalling, control, call handling and ancillary functions for digital local and
31、combined exchanges. TICS 62-04 Recommendation. Performance and availability design objectives for digital local and combined exchanges. CCITT Recommendation Q.5 14. Performance and availability design objectives for digital local and combined exchanges. TICS 62-06 Recommendation. Digital local and c
32、ombined exchange operation and maintenance functions. TICS 68-06 Recommendation. Digital transit exchange operation and maintenance functions. CCITT Recommendation Q.516. Digital local and combined exchange operation and maintenance functions. CCITT Recommendation Q.5 15. Exchange measurements. CCIT
33、T Recommendation Q.5 17. Transmission characteristics. T/CS 68-0 1 Recommendation. Introduction,$eld of application and basic functions for digital transit exchanges. T/CS 68-02 Recommendation. Interfaces for digital transit exchanges. TICS 68-03 Recommendation. Connections, signalling, control, call handling and ancillary functions. TICS 68-04 Recommendation. Performance and availability design objectives for digital transit exchanges. TICS 54- 12 Recommendation. Traffic measurements. Edition of September 15, 1986
