1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T G.776.4 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (10/2014) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Digital terminal equipments Operations, administration and maintenance features of tra
2、nsmission equipment Signal processing network equipment Recommendation ITU-T G.776.4 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMIS
3、SION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELE
4、PHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 General G.700G.709 Coding of voice and audio signals G.710G.729 Principal characteristics of primary multiplex equipment G.730G.739 Principal characteristics o
5、f second order multiplex equipment G.740G.749 Principal characteristics of higher order multiplex equipment G.750G.759 Principal characteristics of transcoder and digital multiplication equipment G.760G.769 Operations, administration and maintenance features of transmission equipment G.770G.779 Prin
6、cipal characteristics of multiplexing equipment for the synchronous digital hierarchy G.780G.789 Other terminal equipment G.790G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 MULTIMEDIA QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.
7、1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.776.4 (10/2014) i Recommendation ITU-T G.
8、776.4 Signal processing network equipment Summary Recommendation ITU-T G.776.4 provides information and requirements for signal processing network equipment (SPNE). It can be applied to traditional networks and next generation networks (NGNs). SPNE such as network echo cancellers (ECs), voice gatewa
9、ys and digital circuit multiplication equipment (DCME) may include signal processing functions (SPFs) (echo cancellation, noise reduction (NR), automatic level control (ALC), circuit multiplication, etc.). Information in this Recommendation is based on actual and planned equipment installed (or to b
10、e installed) in telecommunication networks. This Recommendation describes components, functionality, delay requirements, alarm handling and algorithms used by these devices. Transport, signalling, control, OAM and testing interfaces are also described. History Edition Recommendation Approval Study G
11、roup Unique ID* 1.0 ITU-T G.776.4 2014-10-14 16 11.1002/1000/12233 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/ 11830-en. ii Rec. ITU-T G.776.4
12、 (10/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsib
13、le 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 Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T
14、 study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative b
15、asis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandato
16、ry provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The
17、use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes n
18、o position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property,
19、 protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No
20、part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.776.4 (10/2014) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 5 3.1 Terms defined elsewhere 5 3.2 Terms defined in this Recommendation . 5 4 Abbrevia
21、tions and acronyms 5 5 Conventions 7 6 Signal processing functions 7 6.1 Network echo cancellation . 7 6.2 Network acoustic echo control . 7 6.3 Comfort noise generation . 7 6.4 Noise reduction . 7 6.5 Automatic level control 7 6.6 Speech coding . 7 6.7 Transcoding/multiple encoding 8 6.8 Packet los
22、s concealment . 8 6.9 Voice activity detection 8 6.10 Signal type classification 8 6.11 Digital speech interpolation 8 6.12 Tones/signal generation/detection 8 6.13 FAX demodulation/remodulation . 8 6.14 Voiceband-data low rate encoding/decoding . 9 6.15 Data modem relay . 9 6.16 Circuit-mode bearer
23、 services 9 7 Signal processing network equipment 9 7.1 Type of signal processing equipment . 9 7.2 Application areas of SPNF/SPNE 14 7.3 Delay requirements . 16 8 Transport interfaces 17 8.1 TDM interfaces . 17 8.2 Ethernet interfaces 17 9 Components and transmission characteristics 17 10 Signallin
24、g interfaces . 19 10.1 TDM signalling interfaces 19 10.2 ISC signalling I/F and control function 19 10.3 IP bearer/packet signalling interfaces . 19 11 Management interfaces . 19 iv Rec. ITU-T G.776.4 (10/2014) Page 12 NMS 20 12.1 Managed objects, attributes and notifications 21 13 Control and coord
25、ination procedures 21 13.1 Internal control . 21 13.2 External control 21 13.3 Coordination procedures 21 14 Clock recovery and synchronization 22 14.1 Jitter buffer . 22 15 Reliability and redundancy . 22 16 Environmental aspects of SPNE . 24 16.1 Power supply 24 16.2 Electromagnetic compatibility
26、and emissions 24 16.3 Equipment/system dimensions and mechanics 24 16.4 Environmental conditions . 24 16.5 Reliability and availability . 25 16.6 Test points 25 16.7 Alarm interfaces . 25 17 Conformance and interoperability 25 Bibliography. 26 Rec. ITU-T G.776.4 (10/2014) 1 Recommendation ITU-T G.77
27、6.4 Signal processing network equipment 1 Scope Signal processing network equipment (SPNE) deployed in the network (located in a transmission path from network termination unit to network termination unit) provides functions for voice enhancement and the transport of voice and voiceband services. Th
28、is Recommendation describes these functions and defines performance requirements necessary for successful operation in the network that are not covered in individual SPNE Recommendations. Typical applications of SPNE are also given in this Recommendation. 2 References The following ITU-T Recommendat
29、ions and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefor
30、e encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-al
31、one document, the status of a Recommendation. ITU-T G.108.2 Recommendation ITU-T G.108.2 (2007), Transmission planning aspects of echo cancellers. ITU-T G.114 Recommendation ITU-T G.114 (2003), One-way transmission time. ITU-T G.131 Recommendation ITU-T G.131 (2003), Talker echo and its control. ITU
32、-T G.160 Recommendation ITU-T G.160 (2012), Voice enhancement devices. ITU-T G.161 Recommendation ITU-T G.161 (2012), Interaction aspects of signal processing network equipment. ITU-T G.168 Recommendation ITU-T G.168 (2012), Digital network echo cancellers. ITU-T G.169 Recommendation ITU-T G.169 (20
33、11), Automatic level control devices. ITU-T G.703 Recommendation ITU-T G.703 (1998), Physical characteristics of hierarchical digital interfaces. ITU-T G.704 Recommendation ITU-T G.704 (1998), Synchronous frame structures used at 1544, 6312, 2048, 8448 and 44736 kbit/s hierarchical levels. ITU-T G.7
34、11 Recommendation ITU-T G.711 (1988), Pulse code modulation (PCM) of voice frequencies. ITU-T G.711.0 Recommendation ITU-T G.711.0 (2009), Lossless compression of G.711 pulse code modulation. ITU-T G.718 Recommendation ITU-T G.718 (2008), Frame error robust narrow-band and wideband embedded variable
35、 bit-rate coding of speech and audio from 8-32 kbit/s. ITU-T G.720.1 Recommendation ITU-T G.720.1 (2010), Generic sound activity detector. 2 Rec. ITU-T G.776.4 (10/2014) ITU-T G.722.2 Recommendation ITU-T G.722.2 (2003), Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideban
36、d (AMR-WB). ITU-T G.723.1 Recommendation ITU-T G.723.1 (2006), Dual rate speech coder for multimedia communications transmitting at 5.3 and 6.3 kbit/s. ITU-T G.726 Recommendation ITU-T G.726 (1990), 40, 32, 24, 16 kbit/s Adaptive Differential Pulse Code Modulation (ADPCM). ITU-T G.727 Recommendation
37、 ITU-T G.727 (1990), 5-, 4-, 3- and 2-bit/sample embedded adaptive differential pulse code modulation (ADPCM). ITU-T G.728 Recommendation ITU-T G.728 (2012), Coding of speech at 16 kbit/s using low-delay code excited linear prediction. ITU-T G.729 Recommendation ITU-T G.729 (2012), Coding of speech
38、at 8 kbit/s using conjugate-structure algebraic-code-excited linear prediction (CS-ACELP). ITU-T G.729.1 Recommendation ITU-T G.729.1 (2006), G.729 based Embedded Variable bit-rate coder: An 8-32 kbit/s scalable wideband coder bitstream interoperable with G.729. ITU-T G.732 Recommendation ITU-T G.73
39、2 (1988), Characteristics of primary PCM multiplex equipment operating at 2048 kbit/s. ITU-T G.763 Recommendation ITU-T G.763 (1998), Digital circuit multiplication equipment using G.726 ADPCM and digital speech interpolation. ITU-T G.764 Recommendation ITU-T G.764 (1990), Voice packetization Packet
40、ized voice protocols. ITU-T G.765 Recommendation ITU-T G.765 (1992), Packet circuit multiplication equipment. ITU-T G.766 Recommendation ITU-T G.766 (1996), Facsimile demodulation/remodulation for digital circuit multiplication equipment. ITU-T G.767 Recommendation ITU-T G.767 (1998), Digital circui
41、t multiplication equipment using 16 kbit/s LD-CELP, digital speech interpolation and facsimile demodulation/remodulation. TU-T G.768 Recommendation ITU-T G.768 (2001), Digital circuit multiplication equipment using 8 kbit/s CS-ACELP. ITU-T G.769 Recommendation ITU-T G.769/Y.1242 (2004), Circuit mult
42、iplication equipment optimized for IP-based networks. ITU-T G.776.1 Recommendation ITU-T G.776.1 (1998), Managed objects for signal processing network elements. ITU-T G.799.1 Recommendation ITU-T G.799.1/Y.1451.1 (2004), Functionality and interface specifications for GSTN transport network equipment
43、 for interconnecting GSTN and IP networks. ITU-T G.799.2 Recommendation ITU-T G.799.2 (2009), Mechanism for dynamic coordination of signal processing functions. ITU-T G.799.3 Recommendation ITU-T G.799.3 (2011), Signal processing functionality and performance of an IP-to-IP voice gateway optimized f
44、or the transport of voice and voiceband data. Rec. ITU-T G.776.4 (10/2014) 3 ITU-T G.812 Recommendation ITU-T G.812 (2004), Timing requirements of slave clocks suitable for use as node clocks in synchronization networks. ITU-T G.813 Recommendation ITU-T G.813 (2003), Timing characteristics of SDH eq
45、uipment slave clocks (SEC). ITU-T G.823 Recommendation ITU-T G.823 (2000), The control of jitter and wander within digital networks which are based on the 2048 kbit/s hierarchy. ITU-T G.824 Recommendation ITU-T G.824 (2000), The control of jitter and wander within digital networks which are based on
46、 the 1544 kbit/s hierarchy. ITU-T G.825 Recommendation ITU-T G.825 (2000), The control of jitter and wander within digital networks which are based on the synchronous digital hierarchy (SDH). ITU-T I.231.x Recommendation ITU-T I.231.x-series, Circuit-mode bearer service categories. ITU-T M.3010 Reco
47、mmendation ITU-T M.3010 (2000), Principles for a telecommunications management network. ITU-T M.3100 Recommendation ITU-T M.3100 (2005), Generic network information model. ITU-T M.3400 Recommendation ITU-T M.3400 (2000), TMN management functions. ITU-T M.370x Recommendations ITU-T M.3700 to ITU-T M.
48、3705, Common management services Protocol neutral requirements and analysis. ITU-T P.310 Recommendation ITU-T P.310 (2009), Transmission characteristics for narrow-band digital handset and headset telephones. ITU-T P.313 Recommendation ITU-T P.313 (2007), Transmission characteristics for cordless an
49、d mobile digital terminals. ITU-T P.342 Recommendation ITU-T P.342 (2009), Transmission characteristics for narrow-band digital loudspeaking and hands-free telephony terminals. ITU-T Q.50 Recommendation ITU-T Q.50 (2001), Signalling between Circuit Multiplication Equipment (CME) and International Switching Centres (ISC). ITU-T Q.50.2 Recommendation ITU-T Q.50.2 (2002), Signalling between International Switching
