1、CEPT T/SF*52*E 87 W 2326434 O009435 2 i- l T/SF 52 E Page 1 Recommendation T/SF 52 (Copenhagen 1987) RINGING CADENCES I Recommendation proposed by Working Group T/WG 7 ?Services and facilities? (SF) Text of the Recommendation adopted by ?Telecommitnications? Commission : ?The European Conference of
2、Posts and Telecommunications Administrations, consider iiig - demand has been identified for the use of ringing cadences to inform the called party before answering, about - different ringing cadences are already in use for different applications within Public and PABX networks. Also - therefore sev
3、eral Administrations are of the opinion that harmonization is necessary, - because of the high costs of changing, it is desirable to leave existing standard Public Network and PABX ringing - human factor limitations exist on the number of cadences that can be identified by the user, - the existing a
4、nd proposed services can be grouped into four main categories: the nature of the call, different solutions exist in different countries, cadences as they are as much as possible, O 1. Normal Public Network Calls 2. Internal/External PABX Calls 3. Important Calls 4. Special Calls, recommends - to har
5、monize Public Network and PABX ringing cadences, - to prevent the necessity to make expensive changes to existing ringing equipment, some flexibility has to be been - whenever possible Administrations introducing this service should conform to the cadences as shown on the - the length of the ringing
6、 period within a cadence should be limited to avoid the need for high ringing current built in, attached table, power, Examples of important calls: - Completion of Calls Services - Distinctive Ringing Services - Calls to Bypass Address Possible examples of special calls: - Calls from Operators - Cal
7、ls from Freephone Services - Paging Calls - Diverted Calls - Plus any Non-Standard Calls Requiring Different Ringing Cadences except those Calls as Listed under Important Calls - the length of the long pulses should lie between 800 and 1,200 ms, - the length of the short pulses should lie between 20
8、0 and 400 ms, - the length of the pauses should be at least 150 ms, - period length if applicable should be within 3 and 8 seconds.? Note. Some terminal manufacturers can have problems in designing multiple tone ringers with the figures min 200 ms for pulse and min 150 ms for pause. The sets are bas
9、ed on a different allocation mechanism and these short times can lead to confusion of the user of these sets. In this case min 300 ms should be required from the exchange for pulses and pauses. Edition of January 15, 1988 CEPT T/SF*52*E 87 W 232b4l14 0007436 4 W T/SF 52 E Page 2 User Class Ringing S
10、ignal .Alnn- . . . . . , t Etc. * Published in telephone directory. * Not published in telephone directory. PABX Internal call External/ Public network call Important Special call (display preferred) Special calls diverted e;g. Etc. Public Network Standard ring or address A* Standard ring or address B* Important Special call (display preferred) calls r Etc. 1 “Family telephone” 2 ext. or mini-PABX External/ Public network or vice versa according to adminis- tration policy Special call (display preferred) *Address 1 * Adress 2 c Edition of January 15, 1988
