1、INTERNATIONAL TELECOMMUNICATION UNION ITU-T TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Q.554 SERIES Q: SWITCHING AND SIGNALLING Dig i tal exchanges - Tran sm i ssi on characteristics (I I /96) Transmission characteristics at digital interfaces of digital exchanges ITU-T Recommendation Q.554 (Pr
2、eviously CCIlT Recommendation) STD-ITU-T RECMN Q.559-ENGL L99b 9Bb257L Ob29505 455 ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN SPECIF
3、ICATION OF SIGNALLING SYSTEMS No. 4 AND No. 5 SPECIFICATIONS OF SIGNALLING SYSTEM No. 6 SPECIFICATIONS OF SIGNALLING SYSTEM R1 SPECIFICATIONS OF SIGNALLING SYSTEM R2 DIGITAL EXCHANGES CLAUSES APPLICABLE TO ITU-T STANDARD SYSTEMS Introduction and field of application Exchange interfaces, functions an
4、d connections Design objectives and measurement Transmission characteristics General considerations Logic procedures Interworking of Signalling Systems No. 7 and No. 6 Interworking between Digital Subscriber Signalling System No. 1 and Signalling System No. 7 INTERWORKING OF SIGNALLING SYSTEMS SPECI
5、FICATIONS OF SIGNALLING SYSTEM No. 7 DIGITAL SUBSCRIBER SIGNALLING SYSTEM No. 1 PUBLIC LAND MOBILE NETWORK INTERWORKING WITH SATELLITE MOBILE SYSTEMS INTELLIGENT NETWORK BROADBAND ISDN Q.l-Q.3 Q.4-Q.59 Q.6O-Q.99 Q. 1 00-Q . 1 1 9 Q. 120-Q.249 Q.250-Q.309 Q.31 W.399 Q.400-(2.499 Q.500-Q.599 Q.500-(2.
6、509 Q.510-Q.539 Q.54W.549 Q.55-.599 Q.600-(2.699 Q.600-(2.609 Q.610-Q.697 Q.698 Q.699 Q.700-Q.849 Q.850-Q.999 Q. 1000-Q. 1 O99 Q.1100-Q.1199 Q. 120W.1999 Q.200-Q.2999 _ For further details, please refer to ITU-T List of Recommendations. ITU-T FtCOMMENDATION Q.554 TRANSMISSION CHARACTERISTICS AT DIGI
7、TAL INTERFACES OF DIGITAL EXCHANGES Summary This Recommendation contains detailed transmission characteristics of the digital interface ports of digital exchanges. It covers the requirements for transmission characteristics of the half connections between the digital interfaces and the exchange test
8、 points. The overall characteristics of a connection through the digital exchange involving two interfaces could be obtained by suitably combining the values for the characteristics of the two half connections. Source ITU-T Recommendation 4.554 was revised by ITU-T Study Group 15 (1993-1996) and was
9、 approved under the WTSC Resolution No. 1 procedure on the 8th of November 1996. - STD*ITU-T RECMN Q-5511-ENGL 277b LIBb2592 Ob27507 228 FOREWORD IT (International Telecommunication Union) is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standard
10、ization Sector (IT-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Conference (WTS
11、C), which meets every four years, establishes the topics for study by the IT-T Study Groups which, in their turn, produce Recommendations on these topics. The approval of Recommendations by the Members of the ITU-T is covered by the procedure laid down in WTSC Resolution No. 1, In some areas of info
12、rmation technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative basis with IS0 and IEC. NOTE In this Recommendation, the expression (Administration) is used for conciseness to indicate both a telecommunication administration and a recognized operating age
13、ncy. INTELLECTUAL, PROPERTY RIGHTS The IT draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. The ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual P
14、roperty Rights, whether asserted by IT members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, the IT hadhad not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. How
15、ever, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. O IT 1997 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, inc
16、luding photocopying and microfilm, without permission in writing from the ITU. Recommendation 4.554 (1 1/96) 11 1 2 2.1 2.2 2.3 2.4 2.5 3 3.1 STD-ITU-T RECMN 8-55i-ENGL L99b 4862591 0b29508 Lbi CONTENTS Page General Charactenstics of interfaces Interface characteristics common to digital interfaces
17、. Interface characteristics at interface A 2.2.1 Jitter and wander tolerance at the exchange input . 2.2.2 Maximum time interval error (MTIE) at the exchange output Interface characteristics at interface B 2.3.1 Jitter and wander tolerance at the exchange input . 2.3.2 Maximum Time Interval Error (M
18、TIE) at the exchange output Interface characteristics at interface V, Interface characteristics at other V-type interfaces . Characteristics of 64 kbit/s half connections Half connection characteristics common to all digital interfaces . 3.1.1 Error performance . 3.1.2 Bit integrity . 3.1.3 Bit sequ
19、ence independence . 3.1.4 Absolute group delay Recommendation 4.554 (1 1/96) 1 1 2 2 2 2 2 2 2 2 3 3 . 111 STD*ITU-T RECMN Q.554-ENGL 177b qBb2.571 Ob27507 OTO STD-ITU-T RECMN Q.55q-ENGL 177b m 48b2571 b27510 812 Recommendation 4.554 TRANSMISSION CHARACTERISTICS AT DIGITAL INTERFACES OF DIGITAL EXCH
20、ANGES (revised in 1996) 1 General The field of application of this Recommendation is found in Recommendation 4.500. The signals taken into consideration are passed through the following interfaces as described in Recommendations Q.5 11 and Q.5 12 and Figure UQ.55 1. - - - Interface types V may appea
21、r remote fiom the exchange through the use of digital transmission facilities. When this occurs, there should be no impact on transmission parameters other than delay. Detailed transmission characteristics of the digital interface ports are given in clause 2. Clause 3 covers the requirements for tra
22、nsmission characteristics of the half connections between the digital interfaces and the exchange test points. The half connection comprises an input connection (the one-way 64 kbit/s path from the interface to the test point) and an output connection (the one-way 64 kbits path from the test point t
23、o the interface) as defmed in Recommendation Q.551. Requirements are given for the input connection and the output connection characteristics and the two are not necessarily identical. The overall characteristics of a connection through the digital exchange involving two interfaces can be obtained b
24、y suitably combining the values for the characteristics of the two half connections. For example, the overall characteristics of the connection between a Z interface and the A interface are obtained by combining the Z interface half-connection characteristics given in 3.3/Q.552 with the A interface
25、half-connection requirements given in 3.1. Where bit integrity is maintained on the digital half connection and the error performance requirements are met, the digital half connection will add no impairment to the voice-band performance of a complete connection through the switch (with the exception
26、 of delay). For this reason, the digital half-connection requirements do not include the conventional voice band parameters. The cases where bit integrity is not maintained are not subject of this Recommendation. The values given are to be considered as either “design“ or “performance objectives“ ac
27、cording to the explanation of the terms given in Recommendation G. 102 (Transmission performance objectives and Recommendations) and the particular context. These objectives should be met under the most adverse specified timing and synchronization conditions as given in clause 3/Q.541. Interface A i
28、s for primary rate digital signals at 2048 kbit/s or 1544 kbit/s. Interface B is for secondary rate digital signals at 8448 kbit/s or 6312 kbitk. Interface types V are for digital subscriber line access. 2 Characteristics of interfaces This clause covers requirements for interfaces A, B, and V. Thes
29、e interfaces must meet the requirements for timing and synchronization given in clause 3/Q.541. Recommendation Q.554 (1 1/96) 1 2.1 The general characteristics of the interfaces A, B, V, V, V, and V, are given in Recommendations G.703, G.704, G.706, 4.511 and 4.512. Interface characteristics common
30、to digital interfaces 2.2 The physical and electrical characteristics of interface A are given in clauses 2/G.703 and 6G.703. Interface characteristics at interface A 2.2.1 Jitter and wander tolerance is the ability of the exchange to accept phase deviations on incoming signals without introducing s
31、lips or errors. The j ittedwander tolerance at input A should comply: - - This specification may not be applicable to inputs used solely for synchronization purposes (Le. for deriving the internal timing of the exchange). Jitter and wander tolerance at the exchange input with 3.1. UG.824, for the A
32、interface at 1544 kbit/s; with 3.1.VG.823, for the A interface at 2048 kbit/s. 2.2.2 MTIE is defined in Recommendation G.8 1 1. Limits on MTIE are given in Recommendations G.823 and G.824. Additional information regarding interface A is given in Recommendation 4.541. Maximum time interval error (MTI
33、E) at the exchange output 2.3 The physical and electrical characteristics of interface B are given in clauses 3/G.703 and 7/G.703. Additional information regarding interface B is given in Recommendation 4.54 1. Interface characteristics at interface B 2.3.1 Jitter and wander tolerance is the ability
34、 of the exchange to accept phase deviations on incoming signals without introducing slips or errors. The jittedwander tolerance at input B should comply: - - This specification may not be applicable to inputs used solely for synchronization purposes .e. for deriving the internal timing of the exchan
35、ge). Jitter and wander tolerance at the exchange input with 4.2.2/G.824 for the B interface at 63 12 kbids; with 3.1.1/G.823, for the B interface at 8448 kbids. 2.3.2 MTIE is defined in Recommendation G.811. Limits on MTIE are given in Recommendations G.823 and G.824. Maximum Time Interval Error (MT
36、IE) at the exchange output 2.4 The functional characteristics of the basic access digital section between the V, and T reference point are defined in Recommendations Q.512 and 1.430. The characteristics and parameters of a digital Interface characteristics at interface V, 2 Recommendation 4.554 (111
37、96) STD-ITU-T RECMN Q-55i-ENGL L77b 48b257L Ob27512 b75 transmission system which may form part of the digital section for the ISDN basic rate access are given in Recommendation i.43 1. 2.5 The other V-type interfaces will have transmission characteristics of the A and B interfaces as given in 2.2 a
38、nd 2.3 above. Interface characteristics at other V-type interfaces 3 This clause covers the essential digital characteristics of 64 kbits half connections. Where these requirements are met, the digital half connection will add no impairment to the voice-band performance of a complete connection thro
39、ugh the exchange (with the exception of delay). The voice-band performance of digital half connections may therefore be interpreted by assuming that ideal send and receive sides (see Recommendation G.712) are connected to the digital inputs and outputs respectively. The digital half-connection requi
40、rements also ensure that any connection through the exchange using a pair of digital half connections will provide acceptable performance for non-voice 64 kbits digital services. Characteristics of 64 kbit/s half connections 3.1 Half connection characteristics common to all digital interfaces 3.1.1
41、Error performance The design objective long-term mean Bit Error Ratio (BER) for a single pass of a 64 kbits connection through an exchange between the digital transmissiodswitching interfaces should be 1 in lo- or better. This corresponds to 99.5% error-free minutes assuming that the occurrence of e
42、rrors has a Poisson distribution. 3.1.2 Bit integrity Bit integrity will be maintained if called for to support 64 kbit/s non-telephony services. NOTE - It is understood that to meet this requirement, digital processing devices such as p-/A-law converters, echo suppressors and digital pads must be d
43、isabled for non-telephony calls requiring bit integrity. The means of disabling these devices has yet to be determined. (See 1.2.6.UQ.55 1 .) 3.1.3 Bit sequence independence No limitation should be imposed by the exchange on the number of consecutive binary ones or zeros or any other binary pattern
44、within the 64 kbit/s paths through the exchange. 3.1.4 Absolute group delay The requirements for absolute group delay are given in 3.3.1Q.551. Recommendation 4.554 (11196) 3 Series A Series B Series C Series D Series E Series F Series G Series H Series I Series J Series K Series L Series M Series N
45、Series O Series P Series Q Series R Series S Series T Series U Series V Series X Series Z ITU-T RECOMMENDATIONS SERIES Organization of the work of the ITU-T Means of expression General telecommunication statistics General tariff principles Telephone network and ISDN Non-telephone telecommunication s
46、ervices Transmission systems and media Transmission of non-telephone signals Integrated services digital network Transmission of sound-programme and television signals Protection against interference Construction, installation and protection of cables and other elements of outside plant Maintenance:
47、 international transmission systems, telephone circuits, telegraph) facsimile and leased circuits Maintenance: international sound-programme and television transmission circuits Specifications of measuring equipment Telephone transmission quality Switching and signalling Telegraph transmission Teleg
48、raph services terminal equipment Terminal equipments and protocols for telematic services Telegraph switching Data communication over the telephone network Data networks and open system communication Programming languages STDDITU-T RECMN Q.55Li-ENGL 1996 4862593 Ob295LLi Lib8 * 1 o 4-86 * Printed in Switzerland Geneva, 1997
