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Feature #2592

Use "waiting time" of IMMEDIATE ASSIGN REJECT

Added by laforge 6 months ago. Updated 3 months ago.

Status:
Resolved
Priority:
Normal
Assignee:
Category:
A-bis RSL
Target version:
-
Start date:
10/23/2017
Due date:
% Done:

0%

Spec Reference:

Description

When the BTS responds with an IMMEDIATE ASSIGN REJECT, it can specify a waiting time to the MS.

This waiting time should ideally be load-dependent, i.e. the higher the current load, the longer the waiting time before the MS sends another RACH request.

This is expected to help under severe RACH/SDCCH overload situations


Related issues

Related to OsmoBSC - Feature #2591: ramp up cell slowly based on access control class to avoid severe RACH/SDCCH overload In Progress 10/23/2017
Related to OsmoBSC - Feature #1611: be more efficient in batching IMMEDIATE ASSIGN REJECT messages Stalled 02/23/2016
Related to OsmoBSC - Feature #2722: document RACH tuning parameters more thoroughly, give explanations New 12/08/2017

History

#1 Updated by laforge 6 months ago

  • Related to Feature #2591: ramp up cell slowly based on access control class to avoid severe RACH/SDCCH overload added

#2 Updated by laforge 6 months ago

Timer T3122 is affected by the "wait indication" IE of the IMMEDIATE ASSIGN REJECT. It is coded as a single byte in units of seconds, i.e. up to 255 seconds of waiting time are possible to encode.

See 04.08 Chapters 10.5.2.43 and 9.1.20

#3 Updated by laforge 6 months ago

currently, we use a static value as configured in the VTY as T3122. The default value is 10 seconds.

#4 Updated by laforge 6 months ago

  • Related to Feature #1611: be more efficient in batching IMMEDIATE ASSIGN REJECT messages added

#5 Updated by laforge 5 months ago

  • Related to Feature #2722: document RACH tuning parameters more thoroughly, give explanations added

#6 Updated by laforge 4 months ago

  • Category set to A-bis RSL

#7 Updated by laforge 3 months ago

  • Assignee changed from sysmocom to stsp

#8 Updated by stsp 3 months ago

  • Status changed from New to In Progress

#9 Updated by stsp 3 months ago

Initial patch proposed in https://gerrit.osmocom.org/#/c/6211/

#10 Updated by stsp 3 months ago

  • Status changed from In Progress to Resolved

Above patch has been merged.

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