TS 23.272 — Circuit Switched (CS) fallback in Evolved Packet System (EPS)⚓︎
Release: Rel 15 · Version assessed: 15.0.0 · Network: 4G · Applies to: MME · Interfaces: SGs
Optional capability, configured on request
The network function software implements this specification, and the statement below records that implementation. An Expeto deployment does not configure this capability by default and the acceptance test catalog does not cover it. If your deployment needs any part of it, contact Expeto Product Support: enabling it is configuration work that Expeto scopes and carries out with you.
Mandatory items: 17, of which 17 supported. A further 153 clauses of the specification carry no conformance requirement and are not listed.
Mandatory items⚓︎
| Ref. | Item | Status | Support | Remarks |
|---|---|---|---|---|
| 4.4.1 | MME - MSC Server | Mandatory | Supported | |
| 5.2 | Attach procedure | Mandatory | Supported | |
| 5.3.1 | UE-initiated Detach procedure | Mandatory | Supported | This protocol enables MME to send EPS Detach Indication. |
| 5.3.2 | MME-initiated Detach procedure | Mandatory | Supported | MME shall only be sending EPS Detach Indication. |
| 5.3.3 | HSS-initiated Detach procedure | Mandatory | Supported | |
| 5.4.1 | Combined TA/LA Update Procedure | Mandatory | Supported | |
| 6.2 | Mobile Originating call in Active Mode - PS HO supported | Mandatory | Supported | |
| 6.3 | Mobile Originating call in Active Mode – No PS HO support | Mandatory | Supported | |
| 6.4 | Mobile Originating call in Idle Mode | Mandatory | Supported | |
| 6.5 | Returning back to E-UTRAN | Mandatory | Supported | |
| 6.6 | Mobile Originated or Mobile terminated call rejected by the MME | Mandatory | Supported | |
| 7.2 | Mobile Terminating call in idle mode | Mandatory | Supported | |
| 7.3 | Mobile Terminating call in Active Mode - PS HO supported | Mandatory | Supported | |
| 7.4 | Mobile Terminating call in Active Mode - No PS HO support | Mandatory | Supported | |
| 8.2.2 | Mobile originating SMS in Idle Mode | Mandatory | Supported | |
| 8.2.3 | Mobile originating SMS in Active Mode | Mandatory | Supported | |
| 8.2.5 | Mobile terminating SMS in Active Mode | Mandatory | Supported |
Optional items⚓︎
The specification leaves these 1 items to the implementation; 0 are supported or partially supported. An item marked Not applicable belongs to an area the platform does not provide, named in the Support column. Expand for the full list.
1 optional item
| Ref. | Item | Support | Remarks |
|---|---|---|---|
| 8.2.4 | Mobile terminating SMS in idle mode | Not supported | Mobile-terminated SMS to a UE in idle mode is not supported by the MME; the MSC is expected to page the UE over the CS domain. |
Assessed 2026-09-15 against TS 23.272 version 15.0.0.