23.2.2 Procedure in the GLR

29.1203GPPMobile Application Part (MAP) specification for Gateway Location Register (GLR)Release 17TS

When initiating the dialogue with the GLR, the SMS Gateway MSC must provide the IMSI of the subscriber to whom the short message is directed.

The IMSI is included in the sm-RP-DA information field of the MAP_MT_FORWARD_SHORT_MESSAGE indication.

When receiving a MAP_OPEN indication primitive that is not associated with any MAP service indication primitive and if the dialogue is accepted, the MAP service-user in the GLR issues a MAP_DELIMITER request primitive in order to trigger the local MAP service-provider to confirm the dialogue.

When receiving the first MAP_MT_FORWARD_SHORT_MESSAGE indication from the gateway MSC, the GLR performs some subscriber data checks, if the MAP service primitive is accepted.

The MAP_MT_FORWARD_SHORT_MESSAGE indication primitive is checked by the macro "Check_Indication". If the received MAP service primitive contains errors, the service is aborted and an unexpected data value error or data missing error is returned to the GMSC.

The subscriber identity information that is included in the MAP service indication primitive is checked by the macro "Check_Subscr_Identity_For_MT_SMS" as follows:

If the IMSI is included in the sm-RP-DA information field of the MAP_MT_FORWARD_SHORT_MESSAGE indication, the MAP_OPEN indication received from the gateway MSC shall not include a Destination Reference.

If no Destination Reference has been received and the sm-RP-DA information field does not cover an IMSI the service is aborted in the GLR and the error "Unexpected Data Value" is returned to the GMSC.

The following outcomes from the subscriber data checks can occur in GLR:

– if the mobile subscriber is unknown, the unidentified subscriber error is forwarded to the GMSC;

– if the "Confirmed by HLR" indicator is set to "Not Confirmed", the unidentified subscriber error is forwarded to the GMSC.

If the mobile subscriber is known and "Confirmed by HLR" indicator is set to "Confirmed", the GLR shall successfully retrieves the SGSN Number.

If the GLR is successfully retrieves the SGSN Number it initiates the forward short message procedure to the SGSN. The IMSI is included in the sm-RP-DA information field of the MAP_MT_FORWARD_SHORT_MESSAGE request. More Messages To Send flag is set to TRUE or FALSE depending on the information received from the GMSC.

If the grouping of MAP_OPEN request and MAP_MT_FORWARD_SHORT_MESSAGE request together would need segmenting, these primitives must not be grouped together. The MAP_OPEN request primitive is sent first without any associated MAP service request primitive and the dialogue confirmation must be received before the MAP_MT_FORWARD_SHORT_MESSAGE request is sent.

As a response to the procedure, the GLR will receive the MAP_MT_FORWARD_SHORT_MESSAGE confirmation indicating:

– a successful forwarding of the short message. This indication is passed to the GMSC;

– unsuccessful forwarding of the short message. This indication is passed to the GMSC.

The GLR sets MNRG, if an absent subscriber_SM (except for the case that absent subscriber reason is PurgedMS), an unidentified subscriber or SM delivery failure with error cause MS memory capacity exceeded indication is received from the SGSN.

If the GLR receives an absent subscriber_SM and absent subscriber reason is PurgedMS, the GLR deletes the subscriber data for the user.

Unexpected data value, system failure errors and other errors are simply passed to the GMSC.

If the More Messages To Send flag was TRUE in the MAP_MT_FORWARD_SHORT_MESSAGE request and the previous short message transfer succeeded, then the GLR awaits the next short message.

When receiving the next short message from the GMSC, the GLR sets the More Messages To Send flag according to the information received and starts the service MAP_MT_FORWARD_SHORT_MESSAGE again.

If the More Messages To Send flag was FALSE or the service MAP_MT_FORWARD_SHORT_MESSAGE ends unsuccessfully, the transaction to the gateway MSC is terminated.

The mobile terminated short message transfer procedure in the GLR is shown in figure 23.2/3 and 23.2/4.

Figure 23.2/3 (sheet 1 of 3): Procedure MT_SM_Transfer_GLR

Figure 23.2/3 (sheet 2 of 3): Procedure MT_SM_Transfer_GLR

Figure 23.2/3 (sheet 3 of 3): Procedure MT_SM_Transfer_GLR

Figure 23.2/4 (sheet1 of 2): Macro MT_SM_GLR

Figure 23.2/4 (sheet2 of 2): Macro MT_SM_GLR