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Bug #4558

Why is RRBP set on PACCH Pkt Ul Assignment?

Added by pespin 16 days ago. Updated 16 days ago.

Status:
New
Priority:
Normal
Assignee:
Target version:
-
Start date:
05/20/2020
Due date:
% Done:

0%

Spec Reference:

Description

As far as I cant tell from all TTCN3 PCU tests, osmo-pcu sets always RRBP valid (with N+13) requesting a PACKET CTRL ACK when sending a Packet Uplink Assignment through PACCH towards the MS (as can be seen for instance on TC_mt_mo_ping_pong or f_TC_mo_ping_pong_2phase_access).

So far I don't see the point for doing so, since the purpose of setting that is:
  • During DL data, request DL ACK/NACK
  • During UL ACK/NACK, request PKT CTRL ACK to ACK the ACK.

We need to find in the specs if that's needed for some reason (and also check in the code), and if there's no reason for it, then don't set RRBP during Packet Uplink Assignment.

History

#1 Updated by laforge 16 days ago

On Wed, May 20, 2020 at 04:57:48PM +0000, pespin [REDMINE] wrote:

As far as I cant tell from all TTCN3 PCU tests, osmo-pcu sets always RRBP valid (with N+13) requesting a PACKET CTRL ACK when sending a Packet Uplink Assignment through PACCH towards the MS (as can be seen for instance on TC_mt_mo_ping_pong or f_TC_mo_ping_pong_2phase_access).

it's been ages... but don't you want an ACK for the control message (the assignment itself)?

#2 Updated by pespin 16 days ago

laforge wrote:

it's been ages... but don't you want an ACK for the control message (the assignment itself)?

Well usually the PCU is already setting USF=X for that X being assigned, which means UL blocks will be received before N+13 anyway. Furthermore, I don't see RRBP being set in any of the flow diagrams in book "GPRS from A to Z".

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