07.073GPPAT Command set for GSM Mobile Equipment (ME)Release 1998TS

C.2.1 Select mode +FCLASS

This command puts the TA into a particular mode of operation (data, fax, voice etc.). This causes the TA to process information in a manner suitable for that type of information (rather than for other types of information). The values and meanings of parameter <n> are specified in the following table.

<n> Mode

0 data

1 fax class 1 (TIA‑578‑A)

1.0 fax class 1 (ITU‑T T.31 [11])

2 fax (manufacturer specific)

2.0 fax class 2 (ITU‑T T.32 [12] and TIA‑592)

3…7 reserved for other fax modes

8 voice

9…15 reserved for other voice modes

16..79 reserved

80 VoiceView (Radish)

81..255 reserved

Table C.1: +FCLASS

Voice mode is of particular interest here, and has an additional result code +VCON. Specifically, +VCON indicates that the TA is entering the voice command mode and there is a voice connection to at least one audio input or output. This presupposes that some mechanism has previously initiated a connection to that audio I/O.

C.2.2 Buffer threshold setting +VBT

This refers to integers <lo> and <hi> that indicate levels within the TA transmit buffer at which flow control is asserted and deasserted. The buffer is used for averaging out the irregular timing of data from the computer, so that the data becomes synchronous and may be sent to some audio device.

Table C.2: +VBT

C.2.3 Calling number ID presentation +VCID

The command refers to an integer that allows a called party to enable or disable (<n>=0) the reporting of the ID of calling parties, and specifies the method of presentation of the ID. This is basically the same as GSM supplementary service CLIP (Calling Line Identification Presentation). The presentation may be either formatted (<n>=1) or unformatted (<n>=2):

‑ Formatted presentation : data items are reported in the form of <tag>=<value> pairs.

<tag> <value>

DATE MMDD (month, day)

TIME HHMM (hour, minute)

NMBR calling number or P or O (P = number is private, O = number is unavailable)

NAME subscription listing name

MESG data from other (unknown) tags

‑ Unformatted presentation : here the data is presented in ASCII hex as printable numbers.

Table C.3: +VCID

C.2.4 Receive gain selection +VGR

This refers to the amplification by the TA of audio samples sent from the TA to the computer. The command operates on an integer <n>, range 0…255. Values larger than 128 indicate a larger gain than nominal. Values less than 128 indicate a smaller gain than nominal. The entire range of 0…255 does not have to be provided. A value of zero implies the use of automatic gain control by the TA.

Table C.4: +VGR

C.2.5 Transmit gain selection +VGT

This refers to the amplification by the TA of audio samples sent from the computer to the TA. The command operates on an integer <n>, range 0…255. Values larger than 128 indicate a larger gain than nominal. Values less than 128 indicate a smaller gain than nominal. The entire range of 0…255 does not have to be provided. A value of zero implies the uses of automatic gain control by the TA.

Table C.5: +VGT

C.2.6 Initialise voice parameters +VIP

This recalls manufacturer determined settings <n> of voice parameters. The command is write only. The effect of the command is manufacturer specific.

Table C.6: +VIP

C.2.7 Inactivity timer +VIT

This refers to the value of the inactivity timer in the TA. It is used to monitor activity on the connection between the computer and the TA when the computer is in "transmit" mode and sending audio data to the TA. When the connection has been inactive for the time set by this command, the TA leaves "transmit" mode and reverts to command mode. An integer <n> different than zero implies a time of <n>/10 seconds. A value of zero disables the timer.

Table C.7: +VIT

C.2.8 Line selection +VLS

This determines the selection of sources and destinations of audio samples. An integer is used to label a particular combination of sources and destinations. The integer is defined in an entry in IS‑101 which assumes as a model a TA, a local phone and a phone line. Two additional "manufacturer specific" configurations (16,17) are defined.

‑ label=0: this is the idle state ‑ the phone is not connected to the radio network and no audio paths are used.

‑ label=1: the phone is connected to the radio network and no audio paths involving the internal microphone or internal loudspeaker are selected. This allows the computer to transmit audio data over the radio transmitter by selecting "transmit mode":

Table C.8: +VLS label 1a

This also allows the computer to receive audio data from the radio receiver by selecting "receive mode":

Table C.9: +VLS label 1b

‑ label=4: the phone is not connected to the radio network but there is an audio path to the internal speaker. This allows the computer to play sound by selecting "transmit mode".

Table C.10: +VLS label 4

‑ label=6: the phone is not connected to the radio network but there is an audio path to the internal microphone. This allows the computer to record sound by selecting "receive mode".

Table C.11: +VLS label 6

‑ label=7: the phone is connected to the radio network. The internal microphone is connected to the radio transmitter. The radio receiver is connected to the internal loudspeaker. This allows the computer to enable normal phone operation (a human holding a conversation) by selecting command mode.

Table C.12: +VLS label 7

Table C.13: +VLS

+VCON is returned if an audio path is established or if a connection is made to the radio network.

Manufacturer specific extension (reserved as such by IS‑101)

‑ label=16: the phone is connected to the radio network. There is a path to the internal microphone, which is also connected to the radio transmitter. There is a path to the radio receiver, which is also connected to the internal loudspeaker. This allows the computer to record the sum of transmitted and received audio by selecting "receive mode".

Table C.14: +VLS label 16

‑ label=17: the phone is connected to the radio system and there is a path to the internal loudspeaker and to the radio transmitter. This allows the computer to simultaneously play sound and send audio over the radio by selecting "transmit mode".

Table C.15: +VLS label 17

C.2.9 Receive data state +VRX

This action command causes the TA to get audio data from a source determined by the +VLS command, and send it to the computer. Once the datastream has started, any result codes will be embedded in the data and shielded using the normal <DLE> methods. The receive process is terminated when the computer sends any command to the TA, or by time‑out of the inactivity timer. The command is write only.

Table C.16: +VRX

C.2.10 Select compression method +VSM

This selects the voice compression method <n1>, the voice sampling rate <n2>, the silence compression sensitivity <n3>, and a parameter related to silence expansion <n4>. There are several choices of compression method. IS‑101 does not specify methods, but here is a list of some usual compression methods:

Name Communications system

GSM/full‑rate GSM

GSM/half‑rate GSM

ADPCM/G.721 DECT, CT2

ADPCM/G.723 DECT, CT2

ADPCM/G.726 DECT, CT2

ADPCM/G.727 DECT, CT2

SIGNED PCM POTS

Table C.17: +VSM

NOTE: A value of <n3>=0 implies no silence compression sensitivity. A value of <n4>=0 implies no silence expansion.

C.2.11 DTMF and tone generation +VTS

This command allows the transmission of DTMF tones and arbitrary tones (see note). These tones may be used (for example) when announcing the start of a recording period. The command is write only. In this profile of commands, this command does not operate in data or fax modes of operation (+FCLASS=0,1,2‑7).

NOTE: D is used only for dialling.

The string parameter of the command consists of combinations of the following separated by commas:

1. <DTMF>. A single ASCII character in the set 0‑9, #,*,A‑D. This is interpreted as a single ACSII character whose duration is set by the +VTD command.

NOTE: In GSM this operates only in voice mode.

2. [<tone1>,<tone2>,<duration>]. This is interpreted as a dual tone of frequencies <tone1> and <tone2>, lasting for a time <duration> (in 10 ms multiples).

NOTE: This does not operate in GSM.

3. {<DTMF>,<duration>}. This is interpreted as a DTMF tone of different duration from that mandated by the +VTD command.

NOTE: In GSM this operates only in voice mode.

Table C.18: +VTS

C.2.12 Tone duration +VTD

This refers to an integer <n> that defines the length of tones emitted as a result of the +VTS command. This does not affect the D command. A value different than zero causes a tone of duration <n>/10 seconds. The value zero causes a "manufacturer specific" value.

Table C.19: +VTD

NOTE: In GSM the value of tone duration is preset and cannot be altered.

C.2.13 Transmit data state +VTX

This action command causes the TA to receive audio data from the computer and send it to a destination determined by the +VLS command. Once the audio datastream has started, commands to the TA shall be embedded in the data stream, and shielded using the normal <DLE> methods. The transmit process is terminated by the use of embedded commands or by the time‑out of an inactivity timer. It is recommended that the TA has a buffer to allow the TA to convert potentially bursty data from the computer into synchronous data for "transmission". The command is write only.

Table C.20: +VTX

Annex D (informative):
Bibliography

Informative references:

1) IrDA Serial Infrared Physical Layer Specification

IrDA Serial Infrared MAC and Link Protocol

IrDA Serial Infrared Link Access Protocol

2) PCCA STD‑101 Annex I: Data Transmission Systems and Equipment ‑ Serial Asynchronous Automatic Dialling and Control for Character Mode DCE on Wireless Data Services ‑ Annex I: Command Extensions for Analog Cellular Data Modems

3) TIA IS‑101 Facsimile Digital Interfaces ‑ Voice Control Interim Standard for Asynchronous DCE

4) TIA‑578‑A Facsimile Digital Interfaces ‑ Asynchronous Facsimile DCE Control Standard, Service Class 1

5) TIA‑592 Facsimile Digital Interfaces ‑ Asynchronous Facsimile DCE Control Standard, Service Class 2

6) TIA‑617 Data Transmission Systems and Equipment ‑ In‑Band DCE Control

7) ITU-T Recommendation V.80: In-band DCE control and synchronous data modes for asynchronous DTE

Annex E (informative):
Mobile originated alternating voice/data call example

Figure E.1 illustrates the possible transitions in MO BS 61 call. Responses and result codes generated by TA are in bold face. In this example, data part of the call is asynchronous non‑transparent 9600 bps service.

Figure  E.1: MO BS 61 call

Annex F (informative):
Mobile terminated voice followed by data call example

Figure F.1 illustrates the possible transitions in MT BS 81 call. Responses and result codes generated by TA are in bold face. In this example, data part of the call is asynchronous non‑transparent 9600 bps service.

Figure  F.1: MT BS 81 call

Annex G (informative):
Voice call example

Figure G.1 illustrates the possible transitions in both MT and MO TS 11 calls. Responses and result codes generated by TA are in bold face.

Figure  G.1: TS 11 calls

Annex H (informative):
Change History