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Feature #1822
closedsupport for initial SABM link establishment on Ericsson Abis
Status:
Closed
Priority:
High
Assignee:
Category:
libbsc
Start date:
10/15/2016
Due date:
% Done:
100%
Resolution:
Spec Reference:
Description
Contrary to normal A-bis, Ericsson RBS2000 have the following properties:
- BTS is NT and BSC is TE role, i.e. the BSC should establish LAPD ABM towards the BTS (using SABM..UA.. handshake)
- BTS must re-transmit SABM frames at a specific rate (not too fast, not too slow) for the BTS to recognize this as signalling timeslot. Experiments have shown 300ms seems to work fine.
Achieving this is probably possible by modifying N200 and T200 in case LAPD is used for RBS2000?
Updated by laforge over 7 years ago
- Target version set to RBS2000 with BSC-located PCU
Updated by dexter over 7 years ago
- % Done changed from 0 to 90
Added features to set the lapdm profile on the fly, this allows us to modify the labdm profile parameters on the fly. Also added an ericsson specific profile "lapd_profile_abis_ericsson" in labdm.h. The profile is changed from lapd_profile_abis to lapd_profile_abis_ericsson when start_sabm_in_line() runs.
osmo-nitb now finds the BTS without using rbs_sabm before.
(I was wrong, unplugging the cable was not enough to bring the BTS back into its timeslot scanning mode)
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