eDRX in Germany for NB-IoT

Christian

Hi, is eDRX already supported in Germany? based on the tests I am doing it seems this is not available. When will it be available?
Thanks!

Christian

…. I forgot to mention that my question is related to NB-IoT.

Aleksandra Klinkner

@Christian Hi Christian, thanks for bearing with us. We indeed had some delay in the delivery, however based on current planning we should be able to activate it by the end of this month. We’ll be able to confirm it in the following weeks.

afzal_m

ah that’s awesome new Aleksandra!! Didn’t know that

Christian

@Aleksandra-Klinkner Hi Aleksandra, this is good news… Awesome! I am looking forward to do tests….

Roland Baldin

@Christian Hi Christian, if you are interested in eDRX I really like to understand your use-case in which you like to use it.
Would it be possible to write some words to it? If you don‘t like to write it in a public forum I would be happy if you can write it to roland.baldin@t-systems.com.

Reason why I am interested in this is because I think, there are not so much IoT use-cases in which it can be used as a game changer. Many developers want to use it to implement a very low battery consuming „realtime“ push of the decive as we know it from our mobile. But this not possibe

Regards, Roland

Stefan de Lange

@Roalnd-Baldin

Reason why I am interested in this is because I think, there are not so much IoT use-cases in which it can be used as a game changer. Many developers want to use it to implement a very low battery consuming „realtime“ push of the decive as we know it from our mobile. But this not possibe

Interesting. Why is not possible? I thought that was the intended use for eDRX.

Roland Baldin

@Stefan-de-Lange From the technical perspective it is of cause possible. You can let wake-up your device from sleeping to be able to get delivered eDRX messages every couple of seconds or minutes. But this requires much battery and it is difficult to end-up with a battery live time of many many month.

Regards, Roland

Stefan de Lange

@Roalnd-Baldin I’m not sure if I agree with that statement. It depends a lot on how you configure the I-eDRX parameters. I have seen modems that can do a few uA’s in between eDRX cycles. So if you can keep both the paging time window and the time between eDRX cycles low enough you can achieve very low average currents. Ofcourse this depends on what latency is acceptable for your usecase.

Roland Baldin

@Stefan-de-Lange Hi Stefan, nezwork specialists developed a simulation tool for NB-IoT devices with which it is possible to understand the power consumption and battery live time by simulating different protocolls and NB-IoT features.

Let me try ro access to it. We can have a conf-call and play a little bit with it. Maybe it is interesting for us.
I guess my colleagues are interested in our feedback about it.

Regards, Roland

Stefan de Lange

@Roalnd-Baldin Would be interesting to see how it compares to our measurements on modules. I also used this tool from Nordic Semiconductor: https://devzone.nordicsemi.com/nordic/power/w/opp/3/online-power-profiler-for-lte

Henning Neuse

Unfortunately, our colleagues from the technical department informed us that eDRX has to be postponed again. Introduction is now planned for January 2021.

afzal_m

This post is deleted!

inka O

@Henning-Neuse , is it possible to have the roadmap and the coverage maps for the EDRX support?
Is there a possibility to contact POC from the technical department?
Thanks.

Uta

eDRX for the NB-IoT Network of Deutsche Telekom in Germany has now been officially launched!

lorenz

Hello,
I am using the Quectel BC95-G and a 1nce sim card.
Can you confirm that edrx works also for the 1nce network (which uses the Telekom network?)

Or am I doing something wrong with the AT commands?

# software revision
ati
Quectel
BC95-G
Revision:BC95GJBR01A04

# pinging google dns server. Network is there.
at+nping=8.8.8.8
+NPING:8.8.8.8,110,1840

# 20 second eDRX Value
AT+CEDRXS=1,5,"0010"
OK
AT+CEDRXS?
+CEDRXS:5,"0010"

OK
# checking edrx status. 0 means not working
AT+CEDRXRDP
+CEDRXRDP:0

Using our nb-iot power consumption tool and enabling edrx with the above, I cannot see any paging spikes (which I would expect every 20 seconds). The chart shows 3 UPD packets being sent to the server and the green cross shows the time when it arrived on the server.

Would be happy about some help here, thanks.

Ronan Lacroix

@lorenz ,
Could you please double-check that you are indeed registered in the TDG network (26201), e.g. with command AT+QNWINFO
eDRX is also available to 1nce SIM-cards in our German network and AT+CEDRXRDP should return:
+CEDRXRDP: 5,“0010”,“0010”,“0100”

Best,
Ronan

lorenz

@Ronan-Lacroix
Hi, thanks for the quick answer. The AT+QNWINFO command is not available on my module. But I used at+cops? below and it gives the 26201 network.

So I am registered to the correct network (with automatic selection) but I don’t get the correct +CEDRXRDP: 5,“0010”,“0010”,“0100”. Any other clues? Does the bc95-g module from quectel not support it?

# connected to 26201 operator
at+cops?
+COPS:0,2,"26201"
OK
at+cereg?
+CEREG:5,5,CB52,02992008,9,,,00000101,01000001

# turning off edrx
AT+CEDRXS=0,5
OK
+CSCON:1
+CSCON:0

# turning it back on with urc enabled
AT+CEDRXS=2,5,"0010"
OK
+CSCON:1
+CSCON:0

# not getting a urc, so manually checking the status
AT+CEDRXRDP
+CEDRXRDP:0
AT+CEDRXS?
+CEDRXS:5,"0010"
# waiting for two minutes
AT+CEDRXRDP
+CEDRXRDP:0

Kind Regards,
Lorenz

Ronan Lacroix

@lorenz ,
We will try to reproduce this issue with a BC95-G and get back to you.
We tried earlier with a BG95 (that uses a different chipset), but all tests have been successful, also with a 1nce SIM-card.
Kind regards
Ronan

Ronan Lacroix

@lorenz ,
Looking one more time at your logs above, it looks like you have enabled PSM in parallel to eDRX with a PSM Activity Timer of 10s only.
If this is the case, then eDRX obviously cannot work past those 10 seconds. Do you confirm?
Best,
Ronan

lorenz

@Ronan-Lacroix
Hello Ronan,
thanks for your answer and suggestion.

To prevent the interference between PSM and eDRX, I did another test where I turned off PSM and enabled eDRX. And then it worked. I got the +CEDRXRDP:5,"0010","0010","0000"

Those are the two tests I did

python3 packet-sending.py --interval 60 --finish-after 3 --release-assistance 1 --psm-enabled 0 --edrx-enabled 1
python3 packet-sending.py --interval 60 --finish-after 3 --release-assistance 1 --psm-enabled 0 --edrx-enabled 0

And here are the results with edrx enabled and with edrx disabled:

On the charts you can see that the average power consumption went down from 0.8mA to 0.3mA with eDRX enabled which is good.

I will probably write a blog post about receiving messages during eDRX (I can share it here if you want). I read that the network operator can buffer a MT (mobile terminated) message of up to 100 bytes (can’t quite remember the exact number). Can you confirm that?

Regards,
Lorenz

Ronan Lacroix

@lorenz
Dear Lorenz,
Thanks a lot for the feedback and I’m glad to see eDRX is delivering its promise on energy saving!
Another tip maybe: please consider setting your preferred Periodic TAU Timer to save further energy.
This can be done without setting any PSM activity timer with the CPSMS command, with a TAU-timer of up to 310 hours.
To enable Long-Periodic TAU without PSM, use value “11100000” for parameter <Requested_Active-Time>.
Best regards,
Ronan