1、 International Telecommunication Union ITU-T G.9954TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (01/2007) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Access networks In premises networks Home networking transceivers Enhanced physical, media access, and link layer specif
2、ications ITU-T Recommendation G.9954 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-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTI
3、CS 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 RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION
4、 MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORKS G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.699
5、9 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999ACCESS NETWORKS G.9000G.9999 In premises networks G.9950G.9999 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. G.9954 (01/2007) i ITU-T Recommendation G.9954 Home networkin
6、g transceivers Enhanced physical, media access, and link layer specifications Summary ITU-T Recommendation G.9954 defines the PHY, MAC, LINK and CONVERGENCE protocol stack layers for the G.9954v2 system providing the following features: Operation over phoneline and/or over coax; PHY-layer payload tr
7、ansmission rates of 4 to 320 Mbit/s; Rate adaptive transceivers that optimize data rates and packet error rates for dynamically varying channel conditions on a per-packet basis; QAM modulation technique for communication over phone wire or coaxial cabling; Spectrum notching over phoneline for compat
8、ibility with amateur radio services; Synchronous MAC protocol controlled by a dynamically elected master employing a collision avoidance media access strategy; Support for constant and variable bit-rate data services; Peer-to-peer communication within a master-controlled network; Packet aggregation
9、(packetization) performed within the G.9954v2 protocol stack layer up to latency limits of the service flow and available transmission bandwidth; Quality of service guarantees for bandwidth, jitter, latency and BER; QoS support for services with explicit traffic and rate specifications providing a l
10、ink layer that is well suited for streaming audio and video; Protocol-specific convergence layers; Backward compatible with G.9951/G.9952 in mode A over phoneline using G.9951/G.9952 asynchronous MAC protocol; Coexistence and interoperability between G.9954v1 and G.9954v2 devices in a mixed network;
11、 Compatibility with other phoneline services such as POTS, V.90, ISDN and G.992.1, G.992.2, G.992.3, and G.992.4; Compatibility with other coaxial services such as VDSL, VDSL2 and cable-TV channels; Interoperability between phone and coax PHY layers using spectral modes A and B, thus allowing a mixe
12、d phoneline/coaxial network; Local and remote management of G.9954v2 devices; Provisions for future security extensions. Source ITU-T Recommendation G.9954 was approved on 9 January 2007 by ITU-T Study Group 15 (2005-2008) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. G.9954 (01/2007)
13、FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and
14、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 study groups which, in turn, produce Recommendations on these
15、 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 basis with ISO and IEC. NOTE In this Recommendation, the expres
16、sion “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 mandatory provisions (to ensure e.g. interoperability or applicabilit
17、y) 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 use of such words does not suggest that compliance with the Reco
18、mmendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU 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 no position concerning the evidence, validity or applicability o
19、f 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, protected by patents, which may be required to implement this
20、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 2008 All rights reserved. No part of this publication may be reproduced, by any means whatso
21、ever, without the prior written permission of ITU. ITU-T Rec. G.9954 (01/2007) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions 2 4 Abbreviations and acronyms 4 5 Introduction 5 5.1 G.9954v2 protocol stack overview. 5 5.2 Network reference model . 8 5.3 The protocol stack 13 6 PHY layer spe
22、cification over phoneline. 15 6.1 Overview 15 6.2 Transmitter reference model. 15 6.3 Framing. 16 6.4 Scrambler 20 6.5 Constellation encoder . 21 6.6 QAM modulator . 29 6.7 Minimum device requirements. 29 6.8 Transmitter electrical specification 30 6.9 Receiver electrical specification. 34 6.10 Inpu
23、t impedance . 39 7 PHY layer specification over Coax 41 7.1 Overview 41 7.2 Transmitter reference model. 42 7.3 Framing. 42 7.4 Scrambler 46 7.5 Constellation encoder . 47 7.6 QAM modulator . 55 7.7 Minimum device requirements. 55 7.8 Transmitter electrical specification 56 7.9 Receiver electrical s
24、pecification. 63 7.10 Input impedance . 64 8 Media access protocol specification . 64 8.1 Modes of operation. 66 8.2 Basic CSMA. 68 8.3 Priority access. 69 8.4 Priority mapping. 71 8.5 Network devices and device identifiers (Device_ID) 71 8.6 Data flows and flow identifiers (Flow_ID) 72 8.7 The MAC
25、cycle 72 iv ITU-T Rec. G.9954 (01/2007) Page 8.8 The MAC cycle length . 73 8.9 Media access plan (MAP) 73 8.10 Transmission opportunities (TXOPs). 79 8.11 The G.9954v2 master node functional capabilities 92 8.12 G.9954v2 endpoint node requirements. 94 8.13 MAC layer framing 96 8.14 MAC parameters 99
26、 9 Compatibility specification. 100 9.1 Spectral compatibility with other services on the same wire . 100 9.2 Coexistence and interoperability with G.9951/G.9952 100 9.3 Coexistence and interoperability with G.9954 . 100 10 G.9954v2 quality of service 101 10.1 General description. 101 10.2 Priority-
27、based QoS . 101 10.3 Parameter-based QoS . 103 10.4 Service flows and QoS parameters. 104 10.5 Bandwidth allocation models . 109 10.6 Convergence layer traffic classification . 110 10.7 Flow signalling protocol. 110 10.8 Admission control 111 10.9 QoS support levels 112 11 Link-layer protocol specif
28、ication 113 11.1 Overview 113 11.2 Basic link layer frame format . 115 11.3 Link-layer control frames. 116 11.4 Rate negotiation control function . 119 11.5 Link integrity function 129 11.6 Capability and status announcement 131 11.7 LARQ: Limited automatic repeat request protocol 140 11.8 Vendor-sp
29、ecific formats . 153 11.9 HNT certification and diagnostics protocol . 154 11.10 Link-layer framing extensions 170 11.11 Reed-Solomon coding with intra-frame interleaving (Optional) . 177 11.12 Frame bursting protocol . 184 11.13 MAC cycle synchronization. 186 11.14 Network admission control (Regist
30、ration) protocol. 190 11.15 Master selection protocol . 198 11.16 Flow signalling protocol. 204 11.17 Timestamp report indication message (optional) . 223 ITU-T Rec. G.9954 (01/2007) v Page Annex A Mechanical interface (MDI) 226 A.1 RJ11 MDI connector 226 A.2 F-type female connector. 227 Annex B Net
31、work test loops . 228 B.1 Wire model . 228 B.2 Test loops 229 Appendix I Convergence layers 232 I.1 Overview 232 I.2 Convergence-layer primitives 233 I.3 Convergence layer architecture 240 I.4 Flow set-up triggering 241 I.5 Classification 241 I.6 Convergence layer interfaces to upper protocol layers
32、 242 I.7 Protocol-specific convergence layers. 242 Appendix II Media Independent Interface (MII) Recommendations . 243 II.1 MII overview 243 II.2 G.9954v2 signalling recommendations 245 II.3 The “off-chip“ G.9954v2 convergence layer 247 Appendix III End-to-end architecture. 249 III.1 G.9954v2-to-G.9
33、954v2 protocol stack. 249 III.2 Ethernet-HNT interface 249 III.3 USB-to-G.9954v2 protocol stack . 250 III.4 IEEE 1394-to-G.9954v2 protocol stack . 251 III.5 DOCSIS to G.9954v2 protocol stack . 252 Appendix IV Network synchronization 254 IV.1 Synchronization requirements 254 IV.2 The network synchron
34、ization model 254 IV.3 Summary of synchronization mechanisms. 256 Appendix V Support for variable bit-rate (VBR) flows . 257 V.1 Per-cycle bandwidth request. 257 V.2 UGS + shared transmission opportunity. 257 V.3 UGS + explicit bandwidth requests 258 V.4 UGS + spare bandwidth 258 Appendix VI Quality
35、 of service (QoS) parameters. 259 Appendix VII Simultaneous applications test profiles . 262 Appendix VIII Media access planning guidelines 263 VIII.1 Resource management 263 VIII.2 Media resource allocation and assignment. 263 VIII.3 Burst size management. 263 vi ITU-T Rec. G.9954 (01/2007) Page VI
36、II.4 MAC cycle length management . 263 VIII.5 Traffic policing and shaping. 264 VIII.6 Latency and jitter control 264 VIII.7 MAP generation 265 Bibliography. 266 ITU-T Rec. G.9954 (01/2007) 1 ITU-T Recommendation G.9954 Home networking transceivers Enhanced physical, media access, and link layer spe
37、cifications 1 Scope This Recommendation specifies the interoperability and compatibility for G.9954v2 stations. The requirements are written from the perspective of a compliant transmitter, although some minimum performance requirements are established for receivers. This Recommendation does not spe
38、cify implementation. A G.9954v2 station at a minimum shall be capable of transmitting and receiving over phoneline or over coax. The structure of this Recommendation is as follows: Clause 6: PHY layer specification over phoneline This clause specifies the G.9954v2 PHY layer specification over phonel
39、ine. Clause 7: PHY layer specification over coax This clause specifies the G.9954v2 PHY layer specification over coax. Clause 8: Media access protocol specification This clause specifies the G.9954v2 media access protocol. Clause 9: Compatibility specification This clause describes the method by whi
40、ch backwards compatibility, coexistence and interoperability with G.9954 nodes is achieved in a mixed network of G.9954v2 and G.9954v1 nodes. Clause 10: Quality of service This clause describes the G.9954v2 quality of service framework. Clause 11: Link-layer protocol specification This clause specif
41、ies the required link layer control functionalities. 2 References The following ITU-T Recommendations 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 Recomm
42、endations and other references are subject to revision; users of this Recommendation are therefore 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
43、published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T G.9951 ITU-T Recommendation G.9951 (2001), Phoneline networking transceivers Foundation. ITU-T G.9952 ITU-T Recommendation G.9952 (2001), Phoneline net
44、working transceivers Payload format and link layer requirements. ITU-T G.9953 ITU-T Recommendation G.9953 (2003), Phoneline networking transceivers Isolation function. ITU-T G.9954 ITU-T Recommendation G.9954 (2005), Phoneline networking transceivers Enhanced physical, media access, and link layer s
45、pecifications. DSL TR-069 DSL Forum TR-069 (May 2004), CPE WAN Management Protocol. 2 ITU-T Rec. G.9954 (01/2007) 3 Definitions This Recommendation defines the following terms: 3.1 broadcast packet: A packet with the all-ones destination address (FF.FF.FF.FF.FF.FF). 3.2 capability and status announc
46、ement: A link-layer control protocol that is used to flood status information between stations with low overhead. 3.3 contention-free period: A media access period, allocated to a single network device, in which media access collisions should not (normally) occur. 3.4 convergence layer: A protocol-s
47、pecific sublayer that maps transport layer protocols into the native primitives of the G.9954v2 link layer. 3.5 CS_IFG: The minimum amount of media silence that must be guaranteed between consecutive frame bursts. 3.6 device ID: A unique identifier allocated to a G.9954v2 device by the master after
48、registration. 3.7 endpoint: A G.9954v2 device that is not the master. 3.8 EOF sequence: The 4-symbol sequence that is appended to the physical layer frame, consisting of the first four symbols of the TRN sequence. 3.9 flow: A unidirectional flow of data between network nodes characterized by traffic
49、 with well-defined QoS parameters for throughput, latency, jitter and BER. 3.10 flow ID: A unique identifier of a flow between a source and destination device. 3.11 flow signalling: A G.9954v2 link-layer protocol used to set up, modify and tear down flows. 3.12 flow specification: A specification of the characteristics of a flow in terms of its QoS traffic and rate parameters. 3.13 G.9951/G.9952: A general reference to HNT technology proposed in ITU-T G.9951 and ITU-T G.995
