1、I CEPT T/CD*OL-OL*E BL m 232b434 000295b b W 7 Page I E Recommendation T/CD 01-01 (Inasbruck 1981, revised at Cannes 1983 and Odense 1986) CONCERNING THE GENERAL ENGINEERING REQUIREMENTS FOR DATA CIRCUIT TERMINATING EQUIPMENT FOR ANALOGUE AND DIGITAL NETWORKS Recommendation proposed by Working Group
2、 T/WG 10 “Data communications” (CD) Text of the sevised Recommendation adopted by the “Telecommiications” Commissiol-t : “The Conference of European Post and Telecommunications Administrations, considering - that the working Group CD has studied under the auspices of Question CD 1 the harmonization
3、of data circuit terminating equipment, recommends - that the attached Specification of general engineering requirements for data circuit terminating equipment as contained in Annex 1 to this Recommendation should be taken into account by ail CEPT members when the implementation of a relevant piece o
4、f equipment is being planned by Administrations.” Administrations are free to stipulate additional requirements, and also which of the optional requirements, if any, are to be provided. Note 1: It should be noted that this Recommendation may be revised from time to time. Note 2: The Annex is an inte
5、gral part of the Recommendation. a a I. Edition of October 31, 1987 I CEPT T/CD*Ql-OL*E 1 m 232b4L4 0002957 m i T/CD 01-01 E Page 3 Annex 1 . Contents GENERAL Section I . DCEs for analogue networks . 5 1.1 . Connection to associated equipment . 5 1.2 . Ringingdetection . 6 1.3 . Automatic calling an
6、d answering. 9 1.4 . Telephone line interface 10 1.5 . Line signal requirements 15 1.6 . Test facilities . 19 Section II . DCEs fo i. digital networks 20 11-1 . Connection to associated equipment . 20 11.2 . Line interface . 20 11-3 . Line signal requirements 20 11.4 . Test facilities . 21 O Section
7、 III . Common reqnrettients . 22 III- 1 . 22 111.2 . Facilities selection . 28 111.3 . Methods of measuring the performance of telephone band modems 28 111.4 . Reliability and component selection 36 111.5 . Operating environment . 36 Power supply. protection and interference requirements . . CEPT T/
8、CD*OL-OL*E 83 2326434 0002958 T _ - T/CD 01-01 E Page 5 GENERAL This specification is divided into three parts. Section I is concerned with data circuit terminating equipment (DCE) for voiceband, baseband and groupband circuits as prevalent in predominantly analogue networks. Section II is concerned
9、 with DCEs for lise in predominantly digital networks. Section III is concerned with requirements common to both types of DCEs. This specification shall be read in conjunction with the relevant equipment specification(s). In general, the relevant individual equipment specifications may be split into
10、 two sections or three sections. When the specification is divided into two sections, Section A will contain mandatory requirements and Section B will be concerned with optional requirements. When the specification is divided into three sections, Section A will contain mandatory requirements, Sectio
11、n B will contain national network dependent requirements and Section C will detail optional requirements. It should be noted that different CEPT Administrations may have different preferences for optional requirements. Equipment manufacturers should endeavour to ensure that as far as possible, and c
12、onsistent with good engineering practice, enough flexibility is built into their equipment to enable them to offer different options to different Administrations at an economically acceptable cost. This specification together with the relevant equipment specification(s) detail the facilities require
13、d and the perfor- mance to be obtained. If any incompatibility exists between these specifications the requirements of the equipment specification(s) shall apply. This specification details the general engineering requirements to be met before equipments will be purchased by CEPT Administrations. Ir
14、respective of any approval received from other bodies, written approval shall be obtained from the relevant CEPT Administration for all features, components, etc., to be incorporated in the equipments. As a result of the continuing harmonisation activities within CEPT, the requirements stated in thi
15、s document are under constant review and reflect the position at a given point in time. Future issues may contain major revisions and amendments. Section I. DCEs for malogire networks 1-1. 1-1.1. I- 1.1 * 1 * 1-1.2. 1-1.3. 1-1.3.1, I- 1.3.2. 1-1 -3.3. CONNECTION TO ASSOCIATED EQUIPMENT The binary da
16、ta and control circuits shall satisfy the following requirements in respect of functional characteristics, electrical characteristics and mechanical parameters. Individual equipment specifications shall specify which of the following functional, electrical and mechanical requirements have to be met
17、by the equipment concerned. Definitions of interchange circuits The interchange circuits to be provided in a particular equipment shall be selected from those listed in the latest version of CCIT Recommendation V.24 as directed by the relevant equipment specification. The definitions for interchange
18、 circuits shall be in accordance with this Recommendation. Electrical characteristics The electrical characteristics of the interchange circuits listed and defined in paragraph 1-1.1. shall be in accordance with the latest versions of the CCITT Recommendations V.10, V.ll, V.28 and V.35 as appropriat
19、e. The particular electrical Characteristics to be satisfied by a given equipment shall be as directed by the relevant equipment specifications. Mechanical requirements This paragraph stipulates a set of connectors to be provided to facilitate connection to associated equipment. The 25 pin DCE Inter
20、face connector and pin assignments shall be in accordance with the International Standard ISO/DIS 2110. The 37 pin and 9 pin DCE Interface connectors and pin assignments shall be in accordance with the International Standard ISO/DIS 4902. The 15 pin DCE Interface connector and pin assignments shall
21、be in accordance with the International Standard ISO/DIS 4903. Edition of October 31, 1987 F CEPT T/CD*OL-OL*E m 2326434 0002959 L = TICD 01-01 E Page 6 1-1.3.4. 1-2. 1-2.1. 1-2.2. The particular connector(s) to be provided on a given equipment shall be stipulated in the relevant equipment specifica
22、tions. The allocation of the interchange circuits to the pins of the connectors shall be in accordance with the International Standards stated in paragraphs 1-1.3.1 ., 1-1.3.2. and 1-1.3.3. However, in the event of a conflict between pin allocation stipulated above and any pin allocations stipulated
23、 in the individual equipment specifications, the pin allocations stipulated in the individual equipment specifications shall apply. RINGING DETECTION Ringing signal source description Table 1-1 (T/CD 01-01) gives information relating to automatic ringing signal sources as prevalent in different CEPT
24、 Administrations. It should be noted that generally the ringing current is supplied to the line via a relay coil of variable inductance which may have a value of up to 6H at the ringing frequency. The telephone line The telephone line contributes a resistance of up to a maximum dc loop value as stat
25、ed in Table 1-2 (T/CD O1 -01). During the ringing period both dc and ringing frequency signals may be present simulta- neously on the line. This condition will persist for a short period after the holding loop (Table 1-5 (T/CD 01-01) has been connected to line. When direct exchange line is provided
26、the ringing signals are presented in an approximately balanced manner between the two line wires. When a party (shared service) line is provided the ringing signals will be presented between one wire and earth. Country Austria Belgium Denmark Finland France Fed. Rep. of Germany Greece Italy Netherla
27、nds Norway Portugal Spain Sweden Switzerland United Kingdom I) For PBX. () For local exchanges For small PBX. Level volts RMS 60 75 40- 1 20 at detector 75 f 20 ?“o 60-80 50 30-70 60-90 25-100 25-120 75f15% 70- 120 90 70“ 70- 1 O0 Nominal impedance R 200 1300 2 K in series with 16 pF 450-1 150 Frequ
28、ency Hertz 25-50 25 2.5 25 f 2.5 50f5 25+3 25f3 PABX 50+3 PABX 25k2.5 50f5 25+2 25f2 25 25f2 25f2 50+5 20-55 25 f 20% old PABX 50 25 f 20% 50 25f3 5013 23-28 16-25 Sequence seconds on 1; off 5 PABX on 0.4; off 0.3 on 0.4; off 3 Immediately on 0.3 f 1 ; off 0.45 f 0.45 followed by alternating on 0.75
29、+20% and off 7.5*20% on 1+25% off 416.25% on 1.7 or on 1.5 off 3.3 or off 3.5 on 1 on 1 or on i; off 4 on 1; off 4.5 on 1 off 4 on i; off 4 PABX: on 0.3; off 0.4; on 1; off 5 on 1; off 3 Off40ff5 on 1.5; off 3 +20% on 1 or 1 off 9 or off 5 on 1; off 4 on 0.4; off 0.2; on 0.4; off 2.0 + 10% to -20% T
30、able 1-1 (T/CD 01-01). Ringing signal sources. - Edition of October 31, 1987 CEPT T/CD*Ol-Ol*E l = 232br114 00029bO T/CD 01-01 E Page 7 O 1-2.3. 1-2.3. 1-2.3.2. 1-2.3.2. Country Austria Belgium Denmark Finland France Fed. Rep. of Germany Greece Italy Netherlands Norway Portugal Spain Sweden Switzerl
31、and United Kingdom Maximum loop resistance n 1,600 900 1,200 (Electronic exch.) 1,400 1,800 1,100 1,200 1,500 1,000 1,000 1,500 1,400 1,200 1,200 1,300 1,000 Table 1-2 (T/CD 01-01). Loop resistance. Note. Due to high voltage of the ringing source and the large value of inductance associated with the
32、 telephone exchange equipment it is advisable that connexion to line should not occur when a ringing signal is present on the telephone line since degradation-of the switching elements may result. Ringing detection Ringir-tg detector sesporise time When specified, a ringing detector shall be incorpo
33、rated in the equipment to detect the presence of ringing signals on the telephone line. The response times of the ringing detector shall be as specified in Table 1-3 (T/CD 01-01). An indication of the reception of a ringing condition shall be given within the specified period after the ringing signa
34、l commences at the telephone he terminals. When the ringing detector is used for automatic answering purposes, this indication shall be presented as an ON condition on Circuit 125. When the ringing detector is used for channel selection purposes it shall be the initiation of that selection. Ripigiii
35、g detectos arsaiigements The ringing detector arrangement shall be provided in one of the following forms as directed by the relevant equipment specification. . Series connected ringing detector This form of ringing detector shall be connected in series with the magneto bell and capacitor in the ass
36、ociated telephone. The ringing detector impedance to ringing signals shall be as tabulated. 1-2.3.2.2. Parallel connected ringing detector This form of ringing detector shall be connected in parallel with the bell in the associated telephone. The impedance of the ringing detector to ringing signals
37、shall be as tabulated in Table 1-3 (T/CD 01-01). 1-2.3.2.3. Ringing detector to replace the telephone bell circuit In this form the ringing detector circuit shall replace the telephone bell circuit. Its impedance to ringing signals shall be as tabulated in Table 1-3 (T/CD 01-01). The inclusion of se
38、ries inductance is permitted. 1-2.3.3. RFigiiig detector isolation Isolating arrangements shail be provided to ensure that direct current cannot flow between the telephone line and the equipment. Also, the ringing detector terminals shall be isolated from earth. O Edition of October 31, 1987 CEPT T/
39、CD*DL-OL*E BL W 232b4L4 0002b3 T W T/CD 01-01 E Page 8 Country Austria Belgium Denmark Finland France Greece Italy Netherlands Norway Portugal Spain Sweden Switzerland United Kingdom Ringing detector impedance ka (Note 1) 5 Voltage dependent 2 30 (cf. Figure 1-1 (T/CD 01-01) 10 at 200-3.400 Hz 8-20
40、at 25 and 50 Hz 4 to 10 for 25 and 50 Hz 3.5 at 25 Hz 10 for 23-3.400 Hz 30 at 25 Hz 5 kohm, parallel connection 5 parallel con. 3 (at present) 10 5 parallel con. 5, 0.1 200 ms 0.1 to 0.3 after the ringing signal commences at the telephone line tern-als Note 1. The ringing detector circuit parallel
41、to the bell must operate I = 3 mA at U = 60 VAC. It must recognize a ringing signal within 100 ms. Note 2. The ringing detector circuit must recognize a ringing signal within the 200 ms following its presence. Due to billing protection in electromechanic exchanges, the line must not be held up to 1.
42、8 seconds after the ringing signal is present on the line terminals. Table 1-3 (T/CD 01-01). Ringing detectors. Figure 1-1 (T/CD 01-01). Ringing detector impedance. Edition of October 31, 1987 CEPT T/CD*Ol-Ol*E l m 2326434 0002962 l m _ - 1-3. 1-3.2. 1-3.2.1. 1-3.2.1. T/CD 01-01 E Page 9 AUTOMATIC C
43、ALLING AND ANSWERING “Where individual equipment specifications call for the inclusion of facilities for the disablement of any echo suppressions in the network, or the provision of automatic calling and/or answering facilities, these facilities shall confoim to the requirements of the latest versio
44、ns of CCITT Recommendation unless specified otherwise.” Additional requirements This paragraph specifies certain additional requirements which are applicable within individual CEPT Administrations. Netherlands The circuitry shall be such that a power supply failure or a power supply drop does not le
45、ad to the occupation of the telephone line. Dialling may not start before the reception of the dial tone. The nominal frequency of this dial tone is 150 Hz. The equipment shall disconnect when during 40 seconds no dial tone is received. For a call to a number outside the local area the dialling has
46、to be in two stages. In the first stage the initial digits of the called number are dialled. This is followed by a pause during which a second dial tone of 425 Hz nominal is awaited. In the case of pulse dialling the dialling of the remaining digits of the called number must not commence until this
47、second dial tone is received. When the automatic calling equipment is connected via a private branch exchange (PBX), the dialling may not commence until the dial tone from the PBX is received. The nominal frequency of this dial tone is 150 Hz. Automatic calling equipment shall disconnect itself from
48、 the telephone line when, after dialling a number, the call is not answered within 60 seconds. The disconnection shall last 500 ms to enable the exchange equipment to release itself. , Automatic calling 1-3.2.1.2. Automatic answering Definition: A call is considered to be recognised by the Ringing d
49、etection circuitry (RDC) when the line loop is closed. If a capacitor is used to block the line current, the capacitance shall be 2.2 pF with a minimum working voltage of 250 V DC. If the attenuation introduced by the RDC is more than 0.1 dB within the frequency band 150-3,400 Hz, the RDC shail be disconnected from the line after the call has been recognised. Automatic answering equipment is required to recognise a call within 15 seconds of the reception of the ringing current. However, if during this period the ringing current is interrupted for 5 se
