1、CEPT T/CS*34-O8*E 232b414 0004675 8 c J Receiver O A TfCS34-08E Page 1 Recommendation T/CS 34-08 (Brussels 1980, revised in Nice 1985) AUTOMATIC SENDER FOR PUSH-BUTTON MULTIFREQUENCY SIGNALLING Recommendation proposed by Working Group T/WG 1 1 “Switching and Signalling” (CS) Revised text of the Reco
2、rnmendation adopted by the “Telecommunications” Commission: “The European Conference of Postal and Telecommunications Administrations, considering that telephone network terminals may be equipped with dedicated push-buttons simplifying control operations for the user; - that the automatic sender req
3、uired for the introduction of such dedicated push-buttons is also suitable for signalling between private automatic branch exchanges, and for the simple form of end-to-end data transmission envisaged in Recommendations T/CS 46-02 i and T/CS 46-03 2; - that compatibility of the equipment concerned wi
4、th the multifrequency push-button signalling system specified in Recommendation T/CS 46-02 and T/CS 46-03 must be assured, O recommends to the members, that automatic senders for push-button multifrequency signalling meet the requirements specified below.” 1. AREA OF APPLICATION-GENERAL This Recomme
5、ndation deals with automatic multifrequency senders which are used in the following situations: (a) for signalling from subscribers sets or from private automatic branch exchanges (PABXs) to the public exchange ; (b) for end-to-end data transmission; (c) for signalling between PABXs. It refers to th
6、e basic multifrequency push-button signalling system specified in Recommendation T/CS 46-02 111. The general functional diagram is given in Figure 1 (T/CS 34-08). 2. SIGNAL FREQUENCIES AND CODES O The signal frequencies and codes shall be as specified in Recommendation T/CS 46-02 i. I II 4 II- Line
7、A Figure 1 (T/CS 34-08). Note: The receiver is optional and may be used for dial tone detection, etc. The requirements in this Recommendation apply mainly to interface A. O Edition of May 15, 1986 CEPT T/CS*34-O8*E 232b4L4 0004b7b T T/CS 34-08 E Page 2 3. 3.1. 3.2. 4. 4.1. 4.1.1. 4.1.2. 4.1.3. 4.2.
8、4.3. 4.4. OPERATIONAL CONDITIONS A sender at the subscribers premises is expected to operate under varying environmental conditions. (a) A general purpose sender should operate in temperature controlled locations and partly temperature controlled locations, i.e. in normal living and working areas as
9、 well as entrances, staircases of buildings, factories and industrial plants, etc. The relevant climatic conditions are described in Recommendation T/TR 02-06 5. The sender must meet the requirements within these conditions. (b) A wide temperature range sender should operate in open air as well as s
10、ites with heat traps, i.e. telephone booths and similar installations. The relevant climatic conditions are described in Recom- mendation T/TR 02-06. The wide temperature range sender must meet the requirements within these conditions. The requirements specified shall be met when the sender is insta
11、lled in an exchange or a private automatic branch exchange and is thus subject to the environments therein. The relevant climatic conditions are described in Recommendation T/TR 02-03 4 and the sender must be designed to operate properly within these conditions. SIGNAL OUTPUT REQUIREMENTS Signal req
12、uirements For the duration that the signal is output, but after the completion of the rise time, the following requirements shall be met. Frequency tolerance The output frequencies shall be maintained within f 1.5% of their nominal values. This tolerance shall also include the effect of different li
13、ne impedances offered to the sender. Sending levels The sending levels with a load resistance of 600 ohms shall be: for option 1 : for option 2: with the restriction that the level of the higher frequency component of the compound signal shall be 2 (b) the level of any individual unwanted frequency
14、component shall not exceed the following limits: - in the frequency band 300-4,300 Hz: -33 dBm; - in the frequency band 4,300-28,000 Hz: -37 dBm at 4,300 Hz then falling at 12 dB/octave until - in the frequency band 28,000-70,000 Hz: -70 dBm; - in the frequency band 70,000-200,000 Hz: - 80 dBm; in t
15、he frequency band above 200,000 Hz: -70 dBm. the high frequency group: - 9 dBm f 2 dB, the low frequency group: - 1 1 dBm f 2 dB; the high frequency group: -6 dBmf2 dB, the low frequency group: - 8 dBm f 2 dB; 28,000 Hz; Pause requirements For the duration of the pause, but after the completion of t
16、he fail time, the following requirement regarding unwanted frequency components shall be met: the power level of any single frequency emitted from the sender to line shall not exceed -80 dBm. Rise time The steady state signal requirements shall be met within 5 ms of the commencement of the signai ou
17、tput. Fall time The steady state pause requirements shall be met within 5 ms of the cessation of the signal output. Edition of May 15, 1986 CEPT T/CS*34-OA*E m 2326434 0004677 3 m 4.5. Signal timing The timing diagram is given in Figure 2 (TICS 34-08). risetime fallt me Signai Pause 4.5.1. 4.5.2. 5.
18、 5.1. 5.2. 5.3. 5.4. 5.5. O 5.6. H / signai c duration T, I TICS 34-08 E Page 3 pause duration 1, com mencement of cessation of siSnai output signai output Figure 2 (T/CS 34-08). Timing diagram. Signal duration The signal duration (T,) shall be 70 f 5 ms (excluding risetime). Pause duration The paus
19、e duration (T,) shall be 70* 5 ms (excluding falltime). ELECTRICAL CHARACTERISTICS Impedance The return loss of the device connected to the line against a pure resistance of 600 Ohms shall be at least 14 dB in the frequency band 300-3,400 Hz. Speech suppression During the sending of a sequence of ch
20、aracters, the attenuation of the speech path to the line shall be increased by at least 60 dB. Impedance unbalance to earth The impedance unbalance to earth measured in accordance with the principle of measurement in CCITT Recommendation 4.45 3 shall not be worse than or equal to: - in the frequency
21、 band 40- 300 Hz: 40 dB; in the frequency band 300- 600 Hz: 50 dB; - in the frequency band 600-3,400 Hz: 55 dB. This requirement applies to the total device connected to the line. Power feed If the sender is at a subscribers premises, the power may be derived from the line or from an independent pow
22、er system. If the sender is in an exchange, all voltages used to power it must be obtained from the exchange battery. Overvoltage protection and isolation The sender shall be adequately protected against overvoltages, e.g. lightning, in accordance with national requirements. When an independent powe
23、r system is used, there should be adequate isolation between the power system and the line, in accordance with national requirements. Disturbing signals The sender shall operate correctly in the presence of dial tone and speech. Edition of May 15, 1986 ? CEPT T/CS*34-OB*E = 2326414 0004678 3 1 TICS
24、34-08 E Page 4 References Recommendation T/CS 46-02. Multifrequency signalling system to be used for push-button telephones. Recommendation TICS 46-03. Signalling system for push-button telephones combining basic multifrequency signalling with direct current signalling. CCITT Recommendation 4.45. Tr
25、ansmission characteristics of an international exchange. Recommendation T/TR 02-03. Environmental Conditions in Telecommunication Centres. Recommendation T/TR 02-06. Environmental Conditions for Telecommunication Equipment, Conditions for Telecommunication Equipment at Weather-Protected Locations (excluding Telecommunication Centres with Temperature and Humidity Controls) and in the Open Air. Edition of May 15, 1986
