Support CSFB "Fast Return"
In order to help the MS/UE to return fast[er] to LTE, OsmoMSC should implement the following bit:
- The MSC sends the "CSFB indication" IE as part of BSSMAP CLEAR COMMAND on the A interface (see TS 48.008 220.127.116.11)
This will be used by the BSC to then trigger the inclusion of related IEs in the RR RELEASE
- Status changed from New to In Progress
- % Done changed from 0 to 10
In order to support this, we first need to add the CSFB Indication IE to the BSSMAP CLEAR COMMAND:
https://gerrit.osmocom.org/#/c/libosmocore/+/12829 gsm0808: Add CSFB indication IE to BSSMAP CLEAR COMMAND
- Status changed from In Progress to Stalled
- Assignee changed from dexter to laforge
I've tried to create a TTCN-3 test for this, but it appears that TITAN doesn't correctly parse/decode the CSFB Indicator of the BSSMAP Clear Command. I've posted a related message to the TITAN forum: https://www.eclipse.org/forums/index.php/m/1802832
My TTCN3 test modifications are in the laforge/msc-csfb-fast-return branch of osmo-ttcn3-hacks.git see http://git.osmocom.org/osmo-ttcn3-hacks/log/?h=laforge/msc-csfb-fast-return
Until the presumed TITAN bug is fixed, we cannot use that patch :/
- Status changed from Stalled to In Progress
As seen in #3805, the bug was ours, not one of TITAN.
I've pushed the extended TTCN-3 test as https://gerrit.osmocom.org/#/c/osmo-ttcn3-hacks/+/12935