BSC support for generating ETWS primary notifications
ETWS (Earthquake and Tsunami Warning System) doesn't only use SMSCB, but also contains parts that ensure notification of all MS as quickly as possible. Specifically, this means
- there's a special PAGING REQUEST TYPE 1 sent on all sub-channels of the PCH
- there's an RR APPLICATION INFO message sent over L3 DCCH to all MS with DCH established
- there's a PACKET APPLICATION INFO message sent over PACCH to all MS with TBF established
This ticket is about implementing the required features in the BSC. One of the problems is that TS 48.058 (RSL) doesn't appear to have been updated for support of ETWS.
The paging messages are not encoded by the BSC but by the BTS; RSL PAGING COMMAND contains only the MS Identity, so there's no way to
- generating + sending PAGING REQUEST TYPE 1 with ETWS primary notification
- designing method how pre-encoded PAGING REQUEST TYPE 1 can be sent over A-bis
- generating + sending RR APPLICATION INFO to all established DCCH
- designing method to inform PCU about primary ETWS notification
The RSL PAGING CMD is not suitable for ETWS primary notification, as it only transfers a single identity to be paged, while the ETWS primary notification is more something like "background traffic" on the PCH. It fills the PCH PAGING CMD1 rest octets with (segments of) the ETWS primary notification.
So as a result, the best option is to have a vendor-specific Abis RSL message for enabling/disabling ETWS primary notification broadcasting in the BTS downlink PCH.