Bug 2988 – Wrong L3 filtering formula used for UL power control

Bug 2988 - Wrong L3 filtering formula used for UL power control


Summary:	Wrong L3 filtering formula used for UL power control

Status:	RESOLVED FIXED

Product:	ns-3
Classification:	Unclassified
Component:	lte
Version:	ns-3-dev
Hardware:	All All

Importance:	P3 normal
Assigned To:	Biljana Bojović

URL:
Keywords:

Depends on:
Blocks:
	Show dependency tree / graph

Reported:	2018-09-05 06:37 UTC by Zoraze Ali
Modified:	2018-09-07 08:18 UTC (History)
CC List:	3 users (show)

See Also:

Attachments
Initial patch (12.28 KB, patch) 2018-09-05 06:40 UTC, Zoraze Ali	Details \| Diff
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Description Zoraze Ali 2018-09-05 06:37:17 UTC

Hi, 

In LteUePowerControl::SetRsrp function the formula used to apply L3 filtering is incorrect. The code is the following:

m_rsrp = coeff * m_rsrp + (1 - coeff) * value;

As per the formula mentioned in the standard and in ns-3 documentation (https://www.nsnam.org/docs/models/html/lte-design.html#performing-measurements) it should be:

m_rsrp = coeff * value + (1 - coeff) * m_rsrp;

Moreover, a hard-coded coeff = 0.7 is used for L3 filtering. I think we should use the same coefficient value as in UE RRC, which is sent by an eNB in RRC connection reconfiguration message.

Kind regards,
Zoraze

Comment 1 Zoraze Ali 2018-09-05 06:40:08 UTC

Created attachment 3179 [details]
Initial patch

Attached is the initial patch.

Comment 2 Biljana Bojović 2018-09-05 09:29:13 UTC

Regarding formula OK. 

Regarding filtering, I would prefer that Marco or someone of the original authors confirms.

Comment 3 Marco Miozzo 2018-09-05 09:33:26 UTC

We already had a discussion, I'm fine with the patch.

Comment 4 Zoraze Ali 2018-09-07 08:18:45 UTC

Pushed to changeset 13797:c44705634f6f