3 Definitions and abbreviations

26.2673GPPeCall data transferGeneral descriptionIn-band modem solutionRelease 17TS

3.1 Definitions

For the purposes of the present document, the following terms and definitions apply:

eCall: A manually or automatically initiated emergency call (TS12) from a vehicle, supplemented with a minimum set of emergency related data (MSD), as defined under the EU Commission’s eSafety initiative.

eCall In-band Modem: Modem pair (consisting of transmitters and receivers at IVS and PSAP) that operates full-duplex and allows reliable transmission of eCall Minimum Set of Data from IVS to PSAP via the voice channel of the emergency voice call through cellular and PSTN networks.

eSafety: European Commission sponsored forum to improve safety aspects of European citizens.

feedback frame: Downlink signal transmission interval containing feedback data – corresponds to a time interval of 140 ms or 1 120 samples at an 8 kHz sampling rate.

frame (or: speech frame): Time interval equal to 20 ms (corresponding to one AMR or FR speech frame, represented by 160 samples at an 8 kHz sampling rate).

MSD: The Minimum Set of Data forming the data component of an eCall sent from a vehicle to a Public Safety Answering Point or other designated emergency call centre. The MSD has a maximum size of 140 bytes and includes, for example, vehicle identity, location information and time-stamp.

MSD data frame: Uplink signal transmission interval containing the data of one MSD (after synchronization has been established) – corresponds to a time interval of 1320 ms or 10560 samples (fast modulator) and 2 320 ms or 18560 samples (robust modulator) assuming an 8 kHz sampling rate.

modulation frame: Symbol transmission time interval equal to 2 ms corresponding to 16 samples at 8 kHz sampling rate (fast modulator), or 4 ms corresponding to 32 samples at 8 kHz sampling rate (robust modulator).

synchronization frame: Signal transmission interval containing synchronization information – corresponds to a time interval of 260 ms or 2 080 samples at an 8 kHz sampling rate.

3.2 Abbreviations

For the purposes of the present document, the following abbreviations apply.

ACK Acknowledgement

AMR Adaptive Multi-Rate (speech codec)

BCH Bose-Chaudhuri-Hocquenghem (Code)

BP Band Pass

CRC Cyclic Redundancy Check

CTM Cellular Text telephone Modem

eIM eCall In-band Modem

EU European Union

FEC Forward Error Correction

FR Full Rate (speech codec)

GSM Global System for Mobile communications

HARQ Hybrid Automatic Repeat-reQuest

IR Incremental Redundancy

IVS In-Vehicle System

LP Low Pass

MSD Minimum Set of Data

NACK Negative Acknowledgement

PCCC Parallel Concatenated Convolutional Code

PCM Pulse Code Modulation

PSAP Public Safety Answering Point

PSTN Public Switched Telephone Network

ROM Read Only Memory

RV Redundancy Version

SF Synchronization Frame

UMTS Universal Mobile Telecommunications Systems

VAD Voice Activity Detection