1、 ANSI/TIA/EIA-829-2001 Approved: August 15, 2001 TIA/EIA STANDARD TIA/EIA-829 Tandem Free Operation (TFO) TIA/EIA-829 AUGUST 2001 TELECOMMUNICATIONS INDUSTRY ASSOCIATION The Telecommunications Industry Association Represents the Communications Sector of NOTICE TIA/EIA Engineering Standards and Publi
2、cations are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular n
3、eed. Existence of such Standards and Publications shall not in any respect preclude any member or nonmember of TIA/EIA from manufacturing or selling products not conforming to such Standards and Publications, nor shall the existence of such Standards and Publications preclude their voluntary use by
4、those other than TIA/EIA members, whether the standard is to be used either domestically or internationally. Standards and Publications are adopted by TIA/EIA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, TIA/EIA does not assume any liability to a
5、ny patent owner, nor does it assume any obligation whatever to parties adopting the Standard or Publication. This Standard does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this Standard to estab
6、lish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. (From Standards Proposal No. 3-4683, formulated under the cognizance of the TIA TR-45.4 Subcommittee on Radio to Switching Technology.) Published by g211TELECOMMUNICATIONS INDUST
7、RY ASSOCIATION 2001 Standards and Technology Department 2500 Wilson Boulevard Arlington, VA 22201 PRICE: Please refer to current Catalog of EIA ELECTRONIC INDUSTRIES ALLIANCE STANDARDS and ENGINEERING PUBLICATIONS or call Global Engineering Documents, USA and Canada (1-800-854-7179) International (3
8、03-397-7956) All rights reserved Printed in U.S.A. PLEASE! DONT VIOLATE THE LAW! This document is copyrighted by the TIA and may not be reproduced without permission. Organizations may obtain permission to reproduce a limited number of copies through entering into a license agreement. For informatio
9、n, contact: Global Engineering Documents 15 Inverness Way East Englewood, CO 80112-5704 or call U.S.A. and Canada 1-800-854-7179, International (303) 397-7956 TIA/EIA-829 i Contents 1 Foreword 2 1 Introduction. 1 3 2 References . 1 4 3 Definitions and Abbreviations . 1 5 3.1 Definitions.1 6 3.2 Abbr
10、eviations.2 7 4 General Approach. 3 8 4.1 Background.3 9 4.2 Principle of Tandem Free Operation3 10 5 TFO Frame Structure 5 11 5.1 TFO Frame Structure for 16 kbps Sub-Multiplexing.5 12 5.1.1 Requirements/Assumptions for TFO Frame Structure Definitions5 13 5.1.2 Coding of TFO Frames for 16 kbps Sub-M
11、ultiplexing .5 14 5.1.3 TFO Frames for 16 kbps Sub-Multiplexing9 15 6 TFO Message Structure 22 16 6.1 Definition of the TFO_REQ Messages.23 17 6.1.1 Definition of the TFO_Req_Extension_Block.24 18 6.1.2 Cyclic Redundancy Check.24 19 6.1.3 Definition of the Codec_List_Extension_Block24 20 6.2 Definit
12、ion of the TFO_ACK Messages25 21 6.2.1 Definition of the TFO_Ack_Extension_Block25 22 6.3 Definition of the TFO_TRANS Messages.26 23 6.4 Definition of the TFO_NORMAL Message 26 24 6.5 Definition of the TFO_FILL Message 26 25 6.6 Definition of the TFO_DUP Message (TDMA only).26 26 6.7 Definition of t
13、he TFO_SYL Message (TDMA only)27 27 7 Time Alignment of TFO Frames and TFO Messages. 28 28 7.1 Time Alignment of TFO Messages .28 29 7.2 Time Alignment of TFO Frames.28 30 7.3 Time Alignment of TFO Frames to Downlink TRAU Frames29 31 8 Processes for Tandem Free Operation 31 32 8.1 Rx_TRAU Process.32
14、 33 8.2 Tx_TRAU Process.32 34 8.2.1 Downlink Speech Transmission if TFO is ON.32 35 8.2.2 DTX handling for ANSI-136 33 36 8.2.3 Synchronization and Bit Errors in Received TFO Frames .33 37 8.3 Tx_TFO Process.33 38 8.4 Rx_TFO Process.34 39 8.4.1 Search for and Monitoring of TFO Synchronization .34 40
15、 8.4.2 Errors in TFO Messages and TFO Frames 35 41 8.5 TFO_Protocol Process36 42 8.5.1 Messages from Rx_TRAU or local MSC .36 43 8.5.2 Messages to Tx_TRAU36 44 8.5.3 Messages to and from Tx_TFO.37 45 8.5.4 Messages from Rx_TFO.37 46 8.5.5 Messages from a higher level system (CDMA only).37 47 TIA/EIA
16、-829 ii 9 State Machine of the TFO_Protocol Process for CDMA . 39 1 9.1 Initialization.40 2 9.1.1 Not_Active State.40 3 9.1.2 Wakeup State.40 4 9.2 Establishment .40 5 9.2.1 First_Try State .40 6 9.2.2 Continuous_Retry State.40 7 9.2.3 Periodic_Retry State41 8 9.2.4 Monitor State .41 9 9.2.5 Mismatc
17、h State 41 10 9.3 Contact State 41 11 9.4 Konnect State.41 12 9.5 Operation State.41 13 9.6 Tandem42 14 10 Detailed Description of TFO_Protocol for CDMA 43 15 11 State Machine of the TFO_Protocol Process for TDMA . 55 16 11.1 Initialization.56 17 11.1.1 Not_Active State.56 18 11.1.2 Wakeup State.56
18、19 11.2 Establishment .56 20 11.2.1 First_Try State .56 21 11.2.2 Continuous_Retry State.57 22 11.2.3 Periodic_Retry State57 23 11.2.4 Monitor State .57 24 11.2.5 Mismatch State 57 25 11.3 Contact State 57 26 11.4 Konnect State.57 27 11.5 Operation State.57 28 11.6 Local HO58 29 11.6.1 Fast_Try Stat
19、e58 30 11.6.2 Fast_Contact State58 31 11.7 Distant HO, TFO Interruption58 32 11.7.1 Sync_Lost State.58 33 11.7.2 Re_Konnect State58 34 11.8 Failure State 58 35 12 Detailed Description of TFO_Protocol for TDMA. 59 36 13 Codec Mismatch Resolution and Codec Optimization 70 37 13.1 CDMA TFO Operations70
20、 38 13.2 TDMA TFO Operations70 39 Annex A (Normative) Tandem Free Operation Capability Description and Requirements 1 40 A.1 Introduction1 41 A.2 Terminology2 42 A.2.1 Acronyms .2 43 A.2.2 Definitions 2 44 A.3 Scope .3 45 A.4 Tandem Free Operation Requirements .3 46 A.4.1 Mandatory Tandem Free Opera
21、tion Requirements 3 47 A.4.2 Highly Desired Tandem Free Operation Requirements .5 48 Annex B (Normative) Inband Signaling Protocol: Generic Structure. 1 49 B.1 Scope .1 50 B.2 Generic Structure of Inband Signaling Messages 1 51 TIA/EIA-829 iii B.2.1 Frequency and Order of Bit Transmission.1 1 B.2.2
22、IS_Header.2 2 B.2.3 IS_Command_Block2 3 B.2.4 IS_Extension_Block(s)3 4 B.3 Detailed Specification of IS Messages .3 5 B.3.1 IS_REQ Message.3 6 B.3.2 IS_ACK Message4 7 B.3.3 IS_IPE, IS_TRANS and IS_NORMAL Messages4 8 B.3.4 IS_FILL Message 5 9 B.3.5 IS_DUP Message 6 10 B.3.6 IS_SYL Message .6 11 B.4 K
23、eep_Open_Indication.6 12 B.5 Rules for Sending of IS Messages 7 13 Annex C (Informative) In Path Equipment: Generic Rules and Guidelines . 1 14 C.1 Scope .1 15 C.2 Types of In Path Equipment.1 16 C.3 IS_Compliant IPEs .2 17 C.3.1 Typical IPEs are IS_Passive.2 18 C.3.2 IS Message_Transparency2 19 C.3
24、.3 IPE State Representation3 20 C.3.4 IPE in Sync_Not_Found.4 21 C.3.5 IPE in Sync_Found5 22 C.3.6 IPE in Sync_Lost.5 23 C.3.7 IPE in Keep_Open_Sync5 24 C.3.8 IPE in Keep_Open_Lost.5 25 C.4 IPE Error Handling .6 26 C.5 IPE Transmission Delay6 27 C.5.1 IPE Transmission Delay in Normal_Mode.6 28 C.5.2
25、 IPE Transmission Delay in Transparent_Mode6 29 C.6 Compliance to IS Messages .6 30 C.6.1 Compliance to IS_REQ and IS_ACK Messages.7 31 C.6.2 Compliance to IS_NORMAL Message7 32 C.6.3 Compliance to IS_TRANS_x Messages 7 33 C.6.4 Compliance to IS_TRANS_x_u Messages7 34 C.6.5 Compliance to IS_FILL Mes
26、sage8 35 C.6.6 Compliance to IS_DUP Messages 8 36 C.6.7 Compliance to IS_SYL Messages .8 37 Annex D History 1 38 39 TIA/EIA-829 iv Foreword (this foreword is not part of American National Standard xxxx) 1 2 This standard is based on ETS GSM 08.62, Version 7.0.0, released Feb-1999. It is modified in
27、order to adapt the Tandem Free 3 Operation to the North American Standards TIA/EIA-136 and TIA/EIA-95. 4 5 The present document introduces the Inband Signaling Protocol between Transcoder/Rate Adapter Units for speech traffic 6 channels for the Tandem Free Operation (TFO) of Speech Codecs within the
28、 digital cellular telecommunications system. 7 The contents of this document are subject to continuing work and may change following standard TIA/EIA procedures. 8 TIA/EIA-829 1 1 Introduction 1 This service description document details the Inband Signaling Protocol between Transcoder/Rate Adapter U
29、nits (TRAU) 2 for speech traffic channels for the Tandem Free Operation (TFO) of Speech Codecs, sometimes also termed “Vocoder 3 Bypass“. It is applied to the North American standards TIA/EIA-136 and TIA/EIA-95. 4 5 Annex A is mandatory and defines the capability and requirements used in the develop
30、ment of this TFO standard. 6 7 Annex B is mandatory and describes the general Inband Signaling (IS) Principle. It is identical for all systems (e.g., TIA/EIA-8 136, TIA/EIA-95, GSM) and only updated to include the System Identifications for TIA/EIA-136 and TIA/EIA-95. 9 10 Annex C is informative and
31、 gives the rules for In Path Equipment (IPE). It is identical for all systems (e.g., TIA/EIA-136, 11 TIA/EIA-95, GSM). 12 13 2 References 14 The following documents contain provisions which, through reference in this text, constitute provisions of the present 15 document. 16 References are either sp
32、ecific (identified by date of publication, edition number, version number, etc.) or non-specific. 17 For a specific reference, subsequent revisions do not apply. 18 For a non-specific reference, the latest version applies. 19 A non-specific reference to an ETS shall also be taken to refer to later v
33、ersions published as an EN with the same 20 number. 21 1 TIA/EIA-136-410 “ TDMA Cellular/PCS Radio Interface Enhanced Full-Rate Voice Codec “ (ACELP) 22 2 TIA/EIA-136-420 “VSELP“ 23 3 TIA/EIA-136-430 “US1“ 24 4 TIA/EIA-95-B “Mobile Station Base Station Compatibility Standard for Dual Mode Spread Spe
34、ctrum 25 Systems”, 1998 26 5 TIA/EIA-96C “Speech Service Option Standard for Wideband Spread Spectrum Systems”, 1998 27 6 TIA/EIA/IS-127-1 “Enhanced Variable Rate Codec, Speech Service Option 3 for Wideband Spread 28 Spectrum Digital Systems”, 1998 29 7 TIA/EIA/IS-733-1 “High Rate Speech Service Opt
35、ion 17 for Wideband Spread Spectrum Communication 30 Systems”, 1999 31 8 GSM 08.62: “Digital cellular telecommunication system (Phase 2+); Inband Tandem Free Operation 32 (TFO) of Speech Codecs; Version 7.0.0“. 33 9 ITU-T Recommendation I.130: “Method for the characterization of telecommunication se
36、rvices 34 supported by an ISDN and network capabilities of an ISDN“. 35 36 3 Definitions and Abbreviations 37 3.1 Definitions 38 For the purposes of the present document, the following definitions apply. 39 TRAU Frame is used equivalent to “TRAU Speech Frame“. TRAU Frames are transmitted between TRA
37、U and TRX. 40 TFO Frame is used equivalent to “TFO TRAU Frame“. TFO Frames are transmitted between TFO Partners (e.g. TRAUs). 41 TTL is used to denote the link between the TRAU and the TRX, independent of the system (TIA/EIA-136 or TIA/EIA-95). 42 Silence Descriptor (SID) is the replacement for the
38、speech parameters in TFO frames containing the comfort noise 43 parameters, which are calculated by the MS encoder and used to generate comfort noise in the decoder during speech 44 pauses. 45 TIA/EIA-829 2 Error Concealment Indicator (ECI) is used to signal that a TFO frame does not contain valid s
39、peech parameters. 1 PSTN Interface is used to denominate the 64 kbps PCM link from/to the TRAU. Please note that PSTN Interface does not 2 necessarily mean a connection to a PSTN, but is a general description for a digital 64 kbps PCM line. 3 3.2 Abbreviations 4 For the purposes of the present docum
40、ent, the following abbreviations apply. 5 ACELP Algebraic Code Excited Linear Prediction (TIA/EIA - 136 - 410) 6 BFI Bad Frame Indicator 7 BS Base Station 8 BSC Base Station Controller 9 BTS Base Transceiver System 10 ECI Error Concealment Indicator 11 EVRC Enhanced Variable Rate Codec (TIA/EIA/IS-1
41、27-1) 12 EFRC Enhanced Full-Rate Codec 13 HO Hard Handoff in the case of TIA/EIA-95; Handover with TRAU change involved in the case of 14 TIA/EIA-136 15 IPE In Path Equipment 16 LPC Linear Predictive Codec 17 MS Mobile Station 18 MSC Mobile Switching Center 19 PCM Pulse Coded Modulation 20 PCM sampl
42、e 8-bit value representing the A_Law or _Law coded sample of a speech or audio signal; sometimes 21 used to indicate the time interval between two PCM samples (125s). 22 PCM_Silence either PCM_Alaw_Silence, or PCM_Law_Silence, dependent on application 23 Q8 Speech Codec Service Option 1 for TIA/EIA-
43、95 at 8 kbps (TIA/EIA-96-C) 24 Q13 Speech Codec Service Option 17 for TIA/EIA-95 at 13.3 kbps (TIA/EIA/IS-733-1) 25 SID Silence Descriptor 26 TCME TFO Circuit Multiplication Equipment 27 TFO_ACK TFO Acknowledgement Message 28 T_Bits Time Alignment Bits 29 TFO Tandem Free Operation 30 TFO_FILL TFO Fi
44、ll Message 31 TFO_TRANS TFO Transparent Mode Message 32 TFO_NORMAL TFO Normal Mode Message 33 TFO_DUP TFO (Half) Duplex Mode Message 34 TFO_REQ TFO Request Message 35 TFO_SYL TFO Sync Lost Message 36 TFO Tandem Free Operation 37 TRAU Transcoder and Rate Adapter Unit - this unit performs speech encod
45、ing and decoding on the 38 network side of the communications system according to the codec standard selected 39 TRX Radio transceiver station 40 TTL TRAU-TRX-Link 41 US1 US 1 Codec (TIA/EIA - 136 - 430) 42 VSELP Vector Sum Excited Linear Predictive Coding (TIA/EIA - 136 - 420) 43 TIA/EIA-829 3 4 Ge
46、neral Approach 1 4.1 Background 2 In case of mobile-to-mobile calls (MS-MS calls) in mobile networks without TFO, the speech signal is encoded within the 3 first mobile station for transmission on the air interface, and decoded within the associated first TRAU. The PCM samples 4 are then transported
47、 within the fixed part of the network to the second TRAU using 64kbps traffic links. This second TRAU 5 encodes the speech signal a second time for the transmission on the second air interface, and the associated second mobile 6 station decodes it again. The two Codecs (Encoder-Decoder pair) of the
48、connection are in “Tandem Operation“. 7 8 Tandem Free Operation overcomes the disadvantage of degraded speech quality caused by the two consecutive 9 encoding/decoding processes required in Tandem Operation. 10 11 Tandem Free Operation requires a bi-directional “transparent“ digital channel or path
49、between the TRAUs. Devices within 12 these paths need to be transparent or to be switched off for the TFO Messages and the TFO Frames. To guarantee this 13 digital transparency with out-of-band signaling is not trivial. In particular, out-of-band signaling has insufficient speed to fall 14 back to normal operation in case of sudden interruption of the transparency of the links. 15 16 This TFO recommendation defines therefore an inband signaling protocol, which 17 tests if: 18 an MS-MS call is given; 19 the paths between the TRAUs are digitally transp
