8 Handover/Relocation

23.2313GPPRelease 17SIP-I based circuit-switched core networkStage 2TS

NOTE: All message sequence charts in this clause are examples. All valid handover/relocation message sequences can be derived from the example message sequences and associated message pre-conditions.

8.1 UMTS to UMTS

In the context of the following clauses, the terms RNS or RNC refer also to a GERAN BSS or BSC (respectively) when serving an UE in Iu mode.

8.1.1 Intra-MSC SRNS/SBSS Relocation

The procedures specified in 3GPP TS 23.009 [13] for "Intra-3G_MSC SRNS Relocation" shall be followed. The following clauses describe the additional requirements for the SIP-I based CS core network.

8.1.1.1 Intra-MGW Relocation

The handling of Intra-MSC Intra-MGW SRNS/SBSS Relocation shall be performed in accordance with clause 8.1.1 of 3GPP TS 23.205 [7].

8.1.1.2 Inter-MGW Relocation

Procedures used for the Intra-MSC Inter-MGW SRNS/SBSS Relocation are equivalent to those specified in accordance with 3GPP TS 23.205 [7], with the exception that the procedures for establishing the bearer between the MGW will be in accordance with normal procedures as defined within clause 15.2.

8.1.2 Basic Inter-MSC SRNS/SBSS Relocation

Procedures used for the basic Inter-MSC SRNS/SBSS Relocation are equivalent to those specified in accordance to clause 8.1.2 of 3GPP TS 23.205 [7], with the exception that the call and bearer establishment procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.1.3 Subsequent Inter-MSC SRNS/SBSS Relocation back to the Anchor MSC

Procedures used for the subsequent Inter-MSC SRNS/SBSS Relocation back to the anchor MSC are equivalent to those specified in accordance to clause 8.1.3 of 3GPP TS 23.205 [7], with the exception that the call clearing and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.1.4 Subsequent Inter-MSC SRNS/SBSS Relocation to a third MSC

Procedures used for the subsequent Inter-MSC SRNS/SBSS Relocation to a third MSC are equivalent to those specified in accordance to clause 8.1.4 of 3GPP TS 23.205 [7], with the exception that the call establishment, call clearing, bearer establishment and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.1.5 SRNS/SBSS Relocation with Iu on IP

If IuCS on IP is supported by the MSC server, the Core Network side procedures described in clauses through 8.1.1 to 8.1.4 shall apply, and the Access Network side procedures described in clause 8.1.5 of 3GPP TS 23.205 [2] shall apply.

8.2 UMTS to GSM

In the context of the following clauses, the terms RNS or RNC refer also to a GERAN BSS or BSC (respectively) when serving an UE in Iu mode.

8.2.1 Intra-MSC UMTS to GSM Handover

The procedures specified in 3GPP TS 23.009 [13] for "Intra-3G_MSC Handover from UMTS to GSM" shall be followed. The following clauses describe the additional requirements for the SIP-I based CS core network.

8.2.1.1 Intra-MGW Relocation

The handling of Intra-MSC Intra-MGW UMTS to GSM Handover shall be performed in accordance with clause 8.2.1 of 3GPP TS 23.205 [7].

8.2.1.2 Inter-MGW Relocation

Procedures used for the Intra-MSC Inter-MGW UMTS to GSM Handover are equivalent to those specified in accordance with 3GPP TS 23.205 [7], with the exception that the procedures for establishing the bearer between the MGW will be in accordance with normal procedures as defined within clause 15.2.

8.2.1.3 Intra-MSC UMTS to GSM Handover for A interface over IP

The handling of Intra-MSC UMTS to GSM Handover for A interface over IP shall be performed in accordance with clause 8.2.1.10 of 3GPP TS 23.205 [7].

8.2.2 Basic Inter-MSC UMTS to GSM Handover

Procedures used for the basic Inter-MSC UMTS to GSM Handover are equivalent to those specified in accordance to clause 8.2.2 of 3GPP TS 23.205 [7], with the exception that the call and bearer establishment procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.2.2.1 Basic Inter-MSC UMTS to GSM Handover for A Interface over IP

The handling of Basic MSC UMTS to GSM Handover for A interface over IP shall be performed in accordance with clause 8.2.2.3 of 3GPP TS 23.205 [7].

8.2.3 Subsequent Inter-MSC UMTS to GSM Handover back to the Anchor MSC

Procedures used for the subsequent Inter-MSC UMTS to GSM Handover back to the anchor MSC are equivalent to those specified in accordance to clause 8.2.3 of 3GPP TS 23.205 [7], with the exception that the call clearing and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.2.3.1 Subsequent Inter-MSC UMTS to GSM Handover back to the anchor MSC for A Interface over IP

The handling of Subsequent Inter-MSC UMTS to GSM Handover back to the anchor MSC for A Interface over IP shall be performed in accordance with clause 8.2.3.3 of 3GPP TS 23.205 [7].

8.2.4 Subsequent Inter-MSC UMTS to GSM Handover to a third MSC

Procedures used for the subsequent Inter-MSC UMTS to GSM Handover to a third MSC are equivalent to those specified in accordance to clause 8.2.4 of 3GPP TS 23.205 [7], with the exception that the call establishment, call clearing, bearer establishment and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.3 GSM to UMTS

8.3.1 Intra-MSC GSM to UMTS Handover

The procedures specified in 3GPP TS 23.009 [13] for "Intra-3G_MSC GSM to UMTS Handover" shall be followed. The following clauses describe the additional requirements for the SIP-I based CS core network.

8.3.1.1 Intra-MGW Relocation

The handling of Intra-MSC Intra-MGW GSM to UMTS Handover shall be performed in accordance with clause 8.2.1 of 3GPP TS 23.205 [7].

8.3.1.2 Inter-MGW Relocation

Procedures used for the Intra-MSC Inter-MGW GSM to UMTS Handover are equivalent to those specified in accordance with 3GPP TS 23.205 [7], with the exception that the procedures for establishing the bearer between the MGW will be in accordance with normal procedures as defined within clause 15.2.

8.3.2 Basic Inter-MSC GSM to UMTS Handover

Procedures used for the basic Inter-MSC GSM to UMTS Handover are equivalent to those specified in accordance to clause 8.3.2 of 3GPP TS 23.205 [7], with the exception that the call and bearer establishment procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.3.3 Subsequent Inter-MSC GSM to UMTS Handover back to the Anchor MSC

Procedures used for the subsequent Inter-MSC GSM to UMTS Handover back to the anchor MSC are equivalent to those specified in accordance to clause 8.3.3 of 3GPP TS 23.205 [7], with the exception that the call clearing and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.3.4 Subsequent Inter-MSC GSM to UMTS Handover to a third MSC

Procedures used for the subsequent Inter-MSC GSM to UMTS Handover to a third MSC are equivalent to those specified in accordance to clause 8.3.4 of 3GPP TS 23.205 [7], with the exception that the call establishment, call clearing, bearer establishment and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.3.5 GSM to UMTS Handover with Iu on IP

If IuCS on IP is supported by the MSC server, the Core Network side procedures described in clauses through 8.3.1 to 8.3.4 shall apply, and the Access Network side procedures described in clause 8.3.5 of 3GPP TS 23.205 [2] shall apply.

8.4 GSM to GSM

8.4.1 Intra-MSC Inter-BSS GSM to GSM Handover

The procedures specified in 3GPP TS 23.009 [13] for "Intra-MSC Handover" shall be followed. The following clauses describe the additional requirements for the SIP-I based CS core network.

8.4.1.1 Intra-MGW Relocation

The handling of Intra-MSC Intra-MGW GSM to GSM Handover shall be performed in accordance with clause 8.4.1 of 3GPP TS 23.205 [7].

8.4.1.2 Inter-MGW Relocation

Procedures used for the Intra-MSC Inter-MGW GSM to GSM Handover are equivalent to those specified in accordance with 3GPP TS 23.205 [7], with the exception that the procedures for establishing the bearer between the MGW will be in accordance with normal procedures as defined within clause 15.2.

8.4.1.3 Intra-MSC GSM to GSM Handover for A interface over IP

The handling of Intra-MSC GSM to GSM Handover for A interface over IP shall be performed in accordance with clause 8.4.1.9 of 3GPP TS 23.205 [7].

8.4.2 Basic Inter-MSC GSM to GSM Handover

Procedures used for the basic Inter-MSC GSM to GSM Handover are equivalent to those specified in accordance to clause 8.4.2 of 3GPP TS 23.205 [7], with the exception that the call and bearer establishment procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.4.2.1 Basic Inter-MSC GSM to GSM Handover for A Interface over IP

The handling of Basic Inter-MSC GSM to GSM Handover for A Interface over IP shall be performed in accordance with clause 8.4.2.3 of 3GPP TS 23.205 [7].

8.4.3 Subsequent Inter-MSC GSM to GSM Handover back to the Anchor MSC

Procedures used for the subsequent Inter-MSC GSM to GSM Handover back to the anchor MSC are equivalent to those specified in accordance to clause 8.4.3 of 3GPP TS 23.205 [7], with the exception that the call clearing and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.4.3.1 Subsequent Inter-MSC GSM to GSM Handover back to the anchor MSC for A Interface over IP

The handling of Subsequent Inter-MSC GSM to GSM Handover back to the anchor MSC for A Interface over IP shall be performed in accordance with clause 8.4.3.3 of 3GPP TS 23.205 [7].

8.4.4 Subsequent GSM to GSM Handover to a third MSC

Procedures used for the subsequent Inter-MSC GSM to GSM Handover to a third MSC are equivalent to those specified in accordance to clause 8.4.4 of 3GPP TS 23.205 [7], with the exception that the call establishment, call clearing, bearer establishment and bearer release procedures between the MSCs and MGWs will be in accordance with normal procedures as defined within clause 15.2.

8.4.5 BSS Internal Handover

The handling of Intra-MSC BSS Internal Handover shall be performed in accordance with clause 8.4.5 of 3GPP TS 23.205 [7].