1、ETSI EN 300 778-2 1.2.1 (2001-05) European Standard (Telecommunications series) Access and Terminals (AT); Analogue access to the Public Switched Telephone Network (PSTN); Protocol over the local loop for display and related services; Terminal Equipment requirements; Part 2: Off-hook data transmissi
2、on 2 ETSI EN 300 778-2 V1.2.1 (2001-05) Reference REN/AT-030001-2 Keywords CLIP, PSTN, supplementary service ETSI 650 Route des Lucioles F-O6921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 Siret No 348 623 562 O0017 - NAF 742 C Association but non lucratif enregist
3、re la Sous-prfecture de Grasse (06) No 7803/88 Important notice Individual copies of the present document can be downloaded from: htt!x/w.ettlsi. orq The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in content
4、s between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document
5、may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at If you find errors in the present document, send your comment to: ed itoretsi .fr Copyright Notification No part may be reproduced except as authorized by written permis
6、sion. The copyright and the foregoing restriction extend to reproduction in all media. O European Telecommunications Standards Institute 2001. All rights reserved. ETSI 3 ETSI EN 300 778-2 V1.2.1 (2001-05) Contents Intellectual Property Rights 4 Foreword 4 1 Scope 5 2 References 5 3 Definitions and
7、abbreviations 6 3.1 Definitions 6 3.2 Abbreviations 6 4 4.1 4.2 4.2.1 4.2.2 4.3 4.3.1 4.3.2 4.3.3 4.4 4.4.1 5 5.1 5.2 5.3 5.3.1 5.3.2 5.4 5.5 5.6 Physical layer requirements 6 Loop state . 6 Data transmission 6 Network and TE interoperation 6 TE Alerting Signal (TAS) 7 Timer requirements . 7 Voice p
8、ath muting and end time . 7 TE . Acknowledgement signal 8 Start time . 8 Data signals . 8 Levels 8 Datalink layer . 8 Channel seizure . 8 Mark signal . 8 Message type . 8 Valid message type 8 Unknown message type 9 Message length 9 Checksum . 9 Incorrect checksum 9 6 Presentation layer . message int
9、erpretation 9 7 Safety . 9 ElectroMagnetic Compatibility (EMC) . 9 History . 10 8 ETSI 4 ETSI EN 300 778-2 V1.2.1 (2001-05) Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs,
10、 if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR O00 3 14: “Intellectual Property Rights (IPRs); Essential, orpotentially Essential, IPRs notjed to ETSI in respect OfETSIstandards“, which is available from the ETSI Secretariat. Latest updates are available
11、 on the ETSI Web server (htt:/!wvw.etsi ordj r). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR O00 3 14 (or the updates on the ETSI Web server) which are,
12、or may be, or may become, essential to the present document. Foreword This European Standard (Telecommunications series) has been produced by ETSI Technical Committee Access and Terminals (AT). The present document is part 2 of a multi-part deliverable covering the Protocol over the local loop for d
13、isplay and related services; Terminal Equipment requirements, as identified below: Part 1 : Part 2: “Off-hook data transmission“. “On-hook data transmission“; National transposition dates Date of adoption of this EN: Date of latest announcement of this EN (doa): Date of latest publication of new Nat
14、ional Standard or endorsement of this EN (dop/e): Date of withdrawal of any conflicting National Standard (dow): 27 April 2001 3 1 July 2001 3 1 January 2002 3 1 January 2002 ETSI 5 ETSI EN 300 778-2 V1.2.1 (2001-05) 1 Scope The present document specifies the electrical characteristics and the funct
15、ional characteristics for Terminal Equipment (TE) for connection to the network termination point (NTP) of a Public Switched Telephone Network (PSTN) interface providing a Protocol Over The local Loop For Display Services, based on the protocols defined in EN 300 659-2 i and EN 300 659-3 4. The pres
16、ent document contains only additional requirements with respect to the requirements in EN 300 778-1 2. The present document does not spec any method to cater for distinction between several TE-AC Analogue access to the Public Switched Telephone Network (PSTN); Subscriber line protocol over the local
17、 loop for display (and related) services; Part 2: Off-hook data transmission“. Pl ETSI EN 300 778-1: “Access and Terminals (AT); Analogue access to the Public Switched Telephone Network (PSTN); Protocol over the local loop for display and related services; Terminal Equipment requirements; Part 1 : O
18、n-hook data transmission“. ETSI EN 300 659-1: “Access and Terminals (AT); Analogue access to the Public Switched Telephone Network (PSTN); Subscriber line protocol over the local loop for display (and related) services; Part 1: On-hook data transmission“. ETSI EN 300 659-3: “Access and Terminals (AT
19、); Analogue access to the Public Switched Telephone Network (PSTN); Subscriber line protocol over the local loop for display (and related) services; Part 3: Data link message and parameter codings“. 31 41 ETSI 6 ETSI EN 300 778-2 V1.2.1 (2001-05) 3 Definitions and abbreviations 3.1 Defi nit ions For
20、 the purposes of the present document, the terms and definitions given in EN 300 659-1 3, EN 300 659-2 i, EN 300 778-1 2 and the following apply: off-hook signalling state: state of the TE when in the loop state, the TE is capable of receiving Frequency-Shift Keying (FSK) data transmission, and the
21、normal transmission functions are suspended 3.2 Ab brevi at ions For the purposes of the present document, the abbreviations given in EN 300 659-1 3, EN 300 659-2 i, EN 300 778-1 2 and the following apply: TE-ACK TE Acknowledgement Signal 4 Physical layer requirements 4.1 Loop state There are no loo
22、p state access requirements under the present document. Loop state requirements are given in relevant access standards. 4.2 Data transmission 4.2.1 Network and TE interoperation 1) The LE starts the handshaking sequence by sending a TE Alerting Signal (TAS) and muting of the voice paths at the LE. 2
23、) After detection of the TAS the TE mutes voice paths and disables any manual signalling facility. 3) The TE returns a TE-Acknowledgement signal (TE-ACK) to the LE. 4) The TE enters the off-hook signalling state. 5) The LE recognizes a valid TE-ACK, and starts data transmission to the TE. 6) After d
24、ata transmission is completed, the TE and LE restores any voice paths and the TE enables any manual signalling facility. If the LE does not receive a valid TE-ACK, the data is not transmitted and after a time-out period the TE restores any voice paths and enables any manual signalling facility. If f
25、or any other reason the TE does not receive data transmission, the TE, after a time-out period, restores any voice paths and enables any manual signalling facility. See also figure 1. ETSI 7 Nominal frequencies Signal level Twist Duration 4.2.2 TE Alerting Signal (TAS) 2 130 Hz and 2 750 Hz with the
26、 accuracy f 0,5 % -12 to -35 dBV/tone across line terminals 6 dB max 80msf5ms ETSI EN 300 778-2 V1.2.1 (2001-05) Timer I Value Requirement: The TE shall detect a TAS, DT-AS, as specified in table 1. Description TA Test: Compliance shall be by suppliers declaration. NOTE: The detector must not detect
27、 normal speech or similar signals generated on the line by the users, as a TAS. It is equally important that the detector can recognize the TAS in the presence of normal speech or similar signals from the own user, as the TE is normally not muted when receiving the TAS. 85 ms IThe maximum time betwe
28、en end of the DT-AS and start of the 4.3 Tim er requirements ,. TTE-ACK TF Tu Table 2: Off-hook timers TE-ACK signal Duration of the TE-ACK, a DTMF “D The maximum time the TE waits for the start of data transmission. Measured from the start of the TE-ACK Maximum restoration time to loop state 65 ms
29、to 90 ms 295 ms 120 ms DT-AS TE-ACK DTM F “D“ Off-hook signalling state DATA TRANSMISSION 1 Figure 1 : Handshaking sequence and timing requirements 4.3.1 Voice path muting and end time Requirement: The TE shall mute the voice paths and disable any manual signalling facility before the start of the T
30、E-ACK signal. The voice paths and any manual signalling facility shall remain muted until the end of the data transmission and be restored within T,. If there is no data transmission they shall remain muted until after the Time-out, T, and restoration shall be within Tu (see table 2). Test: Complian
31、ce shall be by suppliers declaration. ETSI 8 ETSI EN 300 778-2 V1.2.1 (2001-05) 4.3.2 TE - Acknowledgement signal Requirement: The TE shall start sending a TE-ACK to the LE, within TA from the end of a TAS. The TE-ACK signal shall be of duration and description as in table 2. Test: Compliance shall
32、be by suppliers declaration. NOTE: It is recommended that the sending of the TE-ACK signal avoids overlap with the received DT-AS signal. 4.3.3 Start time Requirement: The TE shall correctly detect a data transmission starting within 95 ms to T, from the start of the TE-ACK signal (see table 2). Tes
33、t: Compliance shall be by suppliers declaration. 4.4 Data signals Data signals requirements described in EN 300 778-1 2 shall apply, but with the levels as defined in the following clause. 4.4.1 Levels Requirement: The TE shall be capable of correctly receiving FSK signalling tones with levels withi
34、n the range -1 1 dBV to -33 dBV measured between the line terminals and with a twist between the mark and space tones not exceeding 6 dB. Test: Compliance is under study. 5 Datalink layer The structure of the datalink packet is shown in annex D of EN 300 659-1 3. 5.1 Channel seizure NOTE: There is n
35、o channel seizure signal transmitted from the LE in the off-hook state. 5.2 Mark signal Requirement: The TE shall correctly receive datalink packets with the following Mark signal field length - 80 I25 mark bits Test: Compliance is under study. 5.3 Message type 5.3.1 Valid message type Requirement:
36、The TE shall meet the appropriate message type requirements defined in EN 300 778-1 2. Test: Compliance to different message types is under study. ETSI 9 ETSI EN 300 778-2 V1.2.1 (2001-05) 5.3.2 Unknown message type Requirement: If the TE receives an unknown message type, the TE shall restore voice
37、paths and enable any manual signalling facilities within Tu from the end of the FSK data and either ignore the message or indicate an error. Test: Compliance shall be checked by suppliers declaration. 5.4 Message length Requirement: The TE shall meet the message length requirements defined in EN 300
38、 778-1 2. Test: Compliance is under study. 5.5 Checksum Requirement: The TE shall meet the checksum requirements defined in EN 300 778-1 2. Test: Compliance is under study. 5.6 Incorrect checksum Requirement: If an incorrect checksum is detected the TE shall restore voice paths and enable any manual
39、 signalling facility within Tu from the end of the FSK data and shall either ignore the message or indicate an error. Test: Compliance shall be by suppliers declaration. 6 Presentation layer - message interpretation Requirement: Presentation layer message interpretation requirements described in EN
40、300 778- 1 2 shall apply. Test: Compliance is under study. 7 Safety Safety requirements are outside the scope of the present document. Safety requirements are published by CENELEC. 8 Electro Mag net ic Com pat i bi I i ty (E M C) EMC requirements are outside the scope of the present document. ETSI 10 ETSI EN 300 778-2 V1.2.1 (2001-05) v1.2.1 v1.2.1 History December 2000 One-step Approval Procedure OAP 20010427: 2000-12-27 to 2001-04-27 May 2001 Publication I Document history I I Edition 1 I January 1998 I Publication as ETS 300 778-2 ETSI
