LTE 20MHz RB misusage

**dannthemann** · 2016-11-24, 07:49 PM

Hello all.

I am running a Huawei LTE TDD 20MHz system. As defined, there are 100 RB available.

But tracing the real usage, the RB usage is only 80 maximun. It never reaches 100.

Do you know possible reasons for that?

THX!

**Finetopix** · 2016-11-24 07:49 PM

**jkpllan3** · 2016-11-25, 04:57 AM

Remember that in TDD the available RB are used in DL/UL. Probably you have a 80 DL/20 UL configuration...

**dannthemann** · 2016-12-01, 08:47 PM

Thanks!

Which parameter and object should I check to find the configuration setting the ratio of RBs for DL/UL?

Thanks again!

**auto_art** · 2016-12-02, 01:53 AM

Originally Posted by jkpllan3

Remember that in TDD the available RB are used in DL/UL. Probably you have an 80 DL/20 UL configuration...

that probably is not the reason for it. we have 80/20 config too but we could use all 100 RB.

80/20 subframe config. means during a frame 10 ms frame 80% is DL and 20 % is UL. e.g. for 1st TS which is DL for that 1 ms whole 100 RB are available to use. only during DWpts is the subframe where RB for traffic is chipped.

**dannthemann** · 2016-12-02, 02:27 AM

OK, it is strange.

In our case, we have Huawei LTE TDD 20MHz.

We are using a test eNB with a single user that is me testing.

And making trace monitoring, I can see only a maximun of 80 RBs used in DL (see jpg).

Sin título.jpg

Any idea?

Thanks

**juanantonio.vargas** · 2016-12-16, 06:42 PM

Hi,

You are using SA2. You could change the subframe configuration to another one.

http://niviuk.free.fr/lte_tdd.php

BR

**sak2e** · 2016-12-16, 11:19 PM

Please check you cell bandwidth configuration and transport bandwidth capacity.

Originally Posted by dannthemann

OK, it is strange.

In our case, we have Huawei LTE TDD 20MHz.

We are using a test eNB with a single user that is me testing.

And making trace monitoring, I can see only a maximun of 80 RBs used in DL (see jpg).

Sin título.jpg

Any idea?

Thanks

**auto_art** · 2016-12-17, 03:37 AM

can you share this counter for the same time when you put trace?

L.ChMeas.PRB.DL.Used.Avg

**krobelux** · 2016-12-22, 12:21 PM

yo need also to check requested throughput from your drivetest tools. is the requested throughput already maximum?
or need also to check APN-AMBR from RRCconfigurationsuccess message. is the APN throughput granted to give max throughput..

Originally Posted by dannthemann

OK, it is strange.

In our case, we have Huawei LTE TDD 20MHz.

We are using a test eNB with a single user that is me testing.

And making trace monitoring, I can see only a maximun of 80 RBs used in DL (see jpg).

Sin título.jpg

Any idea?

Thanks