[srsran-users] [EXTERNAL] Re: eMBMS throughput limit?

Thu Sep 8 20:48:52 UTC 2022

Thanks Justin, we will plan to upgrade as you suggested.

If we are running the latest SRSRAN version with MCS=24 / PRB=50 / subframe=6/10:
1 – What multicast throughput should we expect?
2 – What unicast throughput should we expect?

Regards,
Ron

From: Justin Tallon <justin.tallon at srs.io>
Sent: Wednesday, September 7, 2022 3:45 PM
To: Sackman (US), Ronald W <ronald.w.sackman at boeing.com>
Cc: J Giovatto <jgiovatto at adjacentlink.com>; srsran-users at lists.srsran.com
Subject: Re: [EXTERNAL] Re: [srsran-users] eMBMS throughput limit?

EXT email: be mindful of links/attachments.

Hey Ron,

I can see from the confs that you are using an older version of SRSRAN, so the first thing I would do is get the latest version of the code.

The parameters you are referencing here are PDSCH and PUSCH which are unicast channels, there is another parameter to set the MCS of MBMS which was added a few years ago, it is not present in the code you are running at the moment and is fixed to MCS=10 which is why you see this low throughput for MBMS.

If you grab the latest code you will be able to set a higher MCS for MBMS in the config file!
Hope this helps!

Regards,
Justin

Justin Tallon

Engineering Manager

Software Radio Systems

[Image removed by sender.]

justin at srs.io<mailto:justin at srs.io>

[Image removed by sender.]

www.srs.io<https://www.srs.io>

[Image removed by sender.]

Barcelona, Spain

[Image removed by sender.]

[Image removed by sender. twitter]<https://twitter.com/srssystems>

[Image removed by sender. linkedin]<https://www.linkedin.com/in/justin-tallon-71807136/>

On Tue, Sep 6, 2022 at 11:27 PM Sackman (US), Ronald W <ronald.w.sackman at boeing.com<mailto:ronald.w.sackman at boeing.com>> wrote:
Hi Justin,

Thank you for the reply, this is helpful.  I am using the iperf client and server commands exactly
as shown on this link:
https://docs.srsran.com/en/latest/app_notes/source/embms/source/index.html

Regarding setting the MCS limit, I see the following in enb.conf:
#pdsch_max_mcs    = -1
#pusch_mcs        = -1
pusch_max_mcs    = 16

Using the ENB console, I verified that the uplink MCS tops out at 16.  The downlink MCS appears to
top out at 27.8.  Should I uncomment pdsch_max_mcs and set it to 24?

From your note, it sounds like the best course of action on my end would be to upgrade to Ubuntu 20.04
and retest for a higher value of p_nrb.  Does this sound reasonable?

Ron

From: Justin Tallon <justin.tallon at srs.io<mailto:justin.tallon at srs.io>>
Sent: Tuesday, September 6, 2022 7:08 AM
To: J Giovatto <jgiovatto at adjacentlink.com<mailto:jgiovatto at adjacentlink.com>>; Sackman (US), Ronald W <ronald.w.sackman at boeing.com<mailto:ronald.w.sackman at boeing.com>>
Cc: srsran-users at lists.srsran.com<mailto:srsran-users at lists.srsran.com>
Subject: [EXTERNAL] Re: [srsran-users] eMBMS throughput limit?

EXT email: be mindful of links/attachments.

Hey Joe & Ron,

Apologies for the delayed response, I have just now seen your emails.
With the default configuration, you should be able to get 11MS/s over the MBMS. This is using  PRB=50 and embms.mcs=20, as well as the maximum assignment of subframes (6/10).
If you increase the MCS=24(maximum allowable for eMBMS, due to the greater number of REs dedicated to reference signals) and set PRB=50, you should get 16MS/s.
I have tested this using ZMQ on Ubuntu 21.04. I have noticed an issue with 100prbs, not the crashing as you described but some PHY layer KOs, I will investigate this and have a fix for the next release.

Ron, can you share the iperf command you are using? It's possible you are flooding the buffers in the RLC which can throw off the eMBMS scheduler, causing a drop in performance.

Joe, I will investigate the issue you have created and get back to you.

Thanks!
Justin

Justin Tallon

Engineering Manager

Software Radio Systems

[Image removed by sender.]

justin at srs.io<mailto:justin at srs.io>

[Image removed by sender.]

www.srs.io<https://www.srs.io>

[Image removed by sender.]

Barcelona, Spain

[Image removed by sender.]

[Image removed by sender. twitter]<https://twitter.com/srssystems>

[Image removed by sender. linkedin]<https://www.linkedin.com/in/justin-tallon-71807136/>

On Thu, Jul 28, 2022 at 4:16 PM J Giovatto <jgiovatto at adjacentlink.com<mailto:jgiovatto at adjacentlink.com>> wrote:
Hi Ron,

This question probably belongs on the srsRAN-emane page but with that being said maybe the kind folks from srs can chime in and

report back any thruput testing they may have done with multicast.

One thing you might want to try is the zmg rf and see if you get different results vs emane to help determine if this is an srs or emane porblem.

Also note there is an issue related to multicast here: https://github.com/srsran/srsRAN/issues/936

Lastly your versions are looking out of date, we are on 21.10 and only supporting Ubuntu 20.04 so any testing will not be a true apples to apples.

Joe

On 7/27/22 19:25, Sackman (US), Ronald W wrote:
Hello,

I am running SRSRAN version 19.9.0 in EMANE, running on Ubuntu 18.04.  I followed the
instructions in the user manual section 5.12 “eMBMS End-to-end” and (with a few modifications)
was able to get it working.  Testing with iperf or MGEN, I am finding that the multicast throughput
is limited to 6Mbps, with an additional 6Mbps of throughput allowed for unicast.  If I
attempt to increase throughput by increasing the enb.conf/p_nrb parameter above
25 (e.g. to 50 or 100), the receiving srsue interface crashes as soon as it receives the
first packet.

Using the following calculator with SRSRAN MCS=26.5 (256QAM), n_prb=25, and 1X1 SiSo, I am
expecting a total of 24.48Mbps downlink bandwidth, out of which I assume multicast would
consume some carve out without reducing the total cell bandwidth.  However, the cell maxes
out at 6Mbps multicast + 6Mbps unicast.
https://www.cellmapper.net/4G-speed

Is this the expected throughput performance?  Am I missing a step to achieve the calculated
throughput for the cell?  I have attached the ENB and UE config files.

Thank you,
Ron

=======================================
Ron Sackman
Technical Fellow
Principal Network Security Architect
Boeing Autonomous Systems / Critical Systems Security
Mountain View CA
Office: 650-316-3749 Cell: 408-930-7358
ronald.w.sackman at boeing.com<mailto:ronald.w.sackman at boeing.com>
Psalm 19:1

_______________________________________________

srsran-users mailing list

srsran-users at lists.srsran.com<mailto:srsran-users at lists.srsran.com>

https://lists.srsran.com/mailman/listinfo/srsran-users

_______________________________________________
srsran-users mailing list
srsran-users at lists.srsran.com<mailto:srsran-users at lists.srsran.com>
https://lists.srsran.com/mailman/listinfo/srsran-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 335 bytes
Desc: image001.jpg
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0006.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.jpg
Type: image/jpeg
Size: 548 bytes
Desc: image002.jpg
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0007.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 338 bytes
Desc: image003.jpg
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0008.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image004.jpg
Type: image/jpeg
Size: 335 bytes
Desc: image004.jpg
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0009.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image005.jpg
Type: image/jpeg
Size: 548 bytes
Desc: image005.jpg
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0010.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image006.jpg
Type: image/jpeg
Size: 338 bytes
Desc: image006.jpg
URL: <https://lists.srsran.com/pipermail/srsran-users/attachments/20220908/38d99d8b/attachment-0011.jpg>