What is System Information Block Type 1 MBMS r14 in LTE?
It is the first MBMS-specific LTE system-information block that points the UE to later MBMS system information.
| Protocol | lte-rrc | Network | lte |
|---|---|---|---|
| Spec | 3GPP TS 36.331 | Spec Section | 5.8, 6.2.2 |
| Direction | Broadcast | Message Type | Broadcast System Information |
| Full message name | LTE RRC SIB1 MBMS r14 |
|---|---|
| Protocol | LTE-RRC |
| Technology | LTE |
| Direction | Broadcast |
| Interface | Uu |
| Signaling bearer / channel | Broadcast / BCCH-DL-SCH |
| Typical trigger | Read by the UE after the earliest MBMS-specific broadcast anchor. |
| Main purpose | Provides the first MBMS-specific broadcast anchor that points the UE into the later MBMS system-information branch. |
| Main specification | 3GPP TS 36.331, 5.8, 6.2.2 |
| Release added | Release 14 |
| Procedures where used | MBMS system information acquisition |
Broadcast LTE RRC message carrying the first MBMS-specific system-information block.
Provides the first MBMS-specific broadcast anchor that points the UE into the later MBMS system-information branch.
SIB1 MBMS r14 is the first MBMS-specific system-information block the UE reads before later MBMS system information.
Call flow position: First MBMS-specific system-information block read after the earliest MBMS-specific anchor.
Typical state: The UE learns how to continue later MBMS system-information acquisition.
Preconditions:
Next likely message: System Information MBMS r14
Call flow position: Refreshed MBMS-specific anchor read when later MBMS system information changed.
Typical state: The message anchors MBMS system-information reacquisition.
Preconditions:
Next likely message: Updated System Information MBMS r14
Previous message(s): MasterInformationBlock-MBMS-r14
Next message(s): SystemInformation-MBMS-r14
Security context: Broadcast information
SystemInformationBlockType1-MBMS-r14 ::= SEQUENCE {
...
}
Read it as the MBMS-specific early broadcast anchor before later MBMS system information.
BCCH-DL-SCH-Message
SystemInformationBlockType1-MBMS-r14: present
| IE | Required | Description |
|---|---|---|
SystemInformationBlockType1-MBMS-r14 | Yes | Carries the first MBMS-specific system-information block. |
SystemInformationBlockType1-MBMS-r14Carries the first MBMS-specific system-information block.
Presence: Required
In practice: In practice, compare this field with the original request and with any later release-dependent optional fields so you can see whether the network accepted the same service model the UE asked for.
Likely cause: SIB1 MBMS r14 may be missing, stale, or not reacquired.
What to inspect: Check whether SIB1 MBMS r14 is present and whether later System Information MBMS follows.
Next step: Treat it as MBMS broadcast-anchoring troubleshooting.
It is the first MBMS-specific LTE system-information block that points the UE to later MBMS system information.
Decode this message with the 3GPP Decoder, inspect the related message database, or open the matching call flow to see where this signaling step fits in the full procedure.