Feature #3778
Support CSFB "Fast Return"
100%
Description
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 3.2.2.121)
This will be used by the BSC to then trigger the inclusion of related IEs in the RR RELEASE
Checklist
- CSFB indication in BSSMAP CLEAR CMD
Related issues
Associated revisions
History
#1 Updated by laforge about 2 years ago
- Related to Feature #3777: Support CSFB "Fast Return" added
#2 Updated by laforge about 2 years ago
- Assignee set to dexter
- Priority changed from Normal to High
#3 Updated by dexter about 2 years ago
- 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
#4 Updated by dexter about 2 years ago
We are about to merge the SGs Interface code, I have added the CSFB Indication IE within a separate patch:
https://gerrit.osmocom.org/#/c/osmo-msc/+/12830 a_iface: Include CSFB Indication into BSSMAP CLEAR COMMAND
#5 Updated by dexter about 2 years ago
- Checklist item CSFB indication in BSSMAP CLEAR CMD set to Done
#6 Updated by laforge about 2 years ago
- % Done changed from 10 to 70
Both libosmocore and omso-msc change have been merged. What's missing is testing it as part of our TTCN-3 testsuite.
#7 Updated by laforge about 2 years ago
- 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
#8 Updated by laforge about 2 years ago
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 :/
#9 Updated by laforge about 2 years ago
- Related to Bug #3805: OsmoMSC sends invalid BSSMAP length field on CSFB CLEAR COMMAND added
#10 Updated by laforge about 2 years ago
- 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
#11 Updated by laforge about 2 years ago
- Status changed from In Progress to Resolved
- % Done changed from 70 to 100
gsm0808: Add CSFB indication IE to BSSMAP CLEAR COMMAND
When a call that was established in a CSFB context ends the CLEAR
COMMAND that is send from the BSC to the MSC should contain a CSFB
indication IE, which consists of just the IE byte itsslef. This
additional IE tells the BSC to include other CSFB related IEs into the
RR Release message.
Change-Id: Id8a75e1da2d5f520064666e4ee413d1c91da6ae3
Related: OS#3778