Content for TS 23.009 Word version: 18.0.0

1… 4… 4.3… 6… 6.2… 6.2.3 6.3… 7… 7.2… 8… 8.1.3… 8.2… 8.2.2… 8.2.4 8.3… 8.3.2… 9… 10… 11… 12… 12.8… 12.8.2 12.8.3 13… 14… 15…

8.2.4 Procedure for subsequent GSM to UMTS handover not requiring a circuit connection
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8.2.4 Procedure for subsequent GSM to UMTS handover not requiring a circuit connection p. 69

As for the subsequent GSM to UMTS handover with a circuit connection, the same two cases of subsequent handover apply:

the UE/MS moves back to the area of 3G_MSC-A;
the UE/MS moves into the area of a third 3G_MSC (3G_MSC-B').

8.2.4.1 Description of subsequent GSM to UMTS handover procedure without circuit connection i): MSC-B to 3G_MSC-A p. 70

The procedure for successful GSM to UMTS handover from MSC-B back to 3G_MSC-A without circuit connection is shown in Figure 28. The only difference with the Figure 26, is that no circuit release is needed between 3G_MSC-A and MSC-B.

Copy of original 3GPP image for 3GPP TS 23.009, Fig. 28: Subsequent GSM to UMTS handover procedure i): Successful handover from MSC-B to 3G_MSC-A not requiring a circuit connection

Figure 28: Subsequent GSM to UMTS handover procedure i): Successful handover from MSC-B to 3G_MSC-A not requiring a circuit connection
(⇒ copy of original 3GPP image)

8.2.4.2 Description of subsequent GSM to UMTS handover procedure without circuit connection ii): MSC-B to 3G_MSC-B' p. 70

The procedure for successful GSM to UMTS handover from MSC-B to 3G_MSC-B' is shown in Figure 29.

The procedure consists of two parts:

a subsequent handover from MSC-B back to MSC-A as described in subclause 7.4.1 (the same procedures apply if MSC-A is replaced by 3G_MSC-A); and
a basic GSM to UMTS handover from MSC-A to 3G_MSC-B' as described in subclause 8.2.2.

The only difference to the equivalent Figure 27 is the omission of the circuit and handover number allocation signallings.

Copy of original 3GPP image for 3GPP TS 23.009, Fig. 29: Subsequent GSM to UMTS handover procedure ii): Successful handover from MSC-B to 3G_MSC-B' without circuit connection

Figure 29: Subsequent GSM to UMTS handover procedure ii): Successful handover from MSC-B to 3G_MSC-B' without circuit connection
(⇒ copy of original 3GPP image)