Content for  TS 27.007  Word version:  18.5.0

Description Defined values Implementation

Description Defined values Implementation

Description Defined values Implementation

Description Defined values Implementation

Description Defined values Implementation

Implementation of commands marked as mandatory is mandatory only if call control functionality is supported.

Description Defined values Implementation

Description Defined values Implementation

The alternating mode call handling (voice and fax, or voice and data) and the data call setup commands are defined such that the dialling command of ITU-T Recommendation V.250 [14] (D) still always originates a call. The purpose is to support all current TE applications using the dialling command as default. Fax calls are controlled following the rules of ITU-T Recommendation T.31 [11] and ITU-T Recommendation T.32 [12] standards. An example where a voice call is originated: An example where a voice call is attempted from a phonebook: Also supplementary services can be controlled using dial command according to TS 22.030. An example of call forwarding on no reply for telephony with the adjustment of the no reply condition timer on 25 seconds: Two new commands are created for controlling the alternating mode calls. First one, Call Mode (+CMOD), selects between single and alternating mode. Because this is a crucial command, it is defined that the value is set back to zero (single mode) after every successfully originated alternating mode call. Also on power-up and factory or user resets, the value is set to zero. The second new command, Hangup Call (+CHUP), is not a replacement of ITU-T Recommendation V.250 [14] command H, but a command which reliably disconnects the call in GSM/UMTS network. This is defined because the H command is used to switch from fax or data mode to voice mode. The setting of GSM/UMTS bearer service (data circuit duplex asynchronous and synchronous, PAD access circuit asynchronous, or data packet duplex synchronous), is done with Select Bearer Service Type (+CBST). It chooses one of the four mentioned bearer services, the data rate of the service (or actually the modulation when modem IWFs are used), and enables or disables RLP. Command Radio Link Protocol (+CRLP) is used to set the RLP parameters in the radio path. Service Reporting Control command (+CR) is defined similarly as the reporting of modulation, V.18, error control, and data compression which are ITU-T Recommendation V.250 [14] features used to show information about the type of the established connection before the CONNECT intermediate result code. +CR command has one subparameter which specifies whether the intermediate result code +CR: <serv> is returned or not. The result code is typically returned before any ITU-T Recommendation V.250 [14] reporting result codes. An example of setting up an asynchronous 9600 bit/s modem connection with service reporting: As GSM/UMTS network offers more information about the reason of the failure in call originating and answering than normal PSTN, it is useful to add an extra command to return this information to the TE. This information should not be returned always after unsuccessful call originating or answering, because many TE applications look for just the regular NO CARRIER, BUSY, NO ANSWER and CONNECT messages. Action command Extended Error Report (+CEER) does not have any subparameters, and it returns the cause of the latest call setup failure. This information can be the textual presentation of the GSM/UMTS network failure code (refer TS 24.008 Annex H), or some other information defined by the TA manufacturer.