@mybeepad-0

One day you will have dreams about AT-commands

(I am talking from experience) 😅

@HNEE Hi Daniel, many thanks. I will check.
I am in the process of acquiring documentation from Quectel distributor but community can provide documents much faster!
Thanks,
Peter

@rxtx Perfect!

Hi @Tibor-Keller you can have a look at this online coverage map for Magyar Telekom’s NB-IoT network https://www.telekom.hu/static-la/sw/file/Nb_IoT_Lefedettseg.pdf

Copy / paste what one of my colleagues wrote:

I must admit I am not sure regarding the polarization used on our cell sites, an article stating that most operators use +/- 45° is probably correct. I’ll try to find out and let you know.

That said, knowing the base station antenna’s polarization is not as important as it might appear at first glance. In fact, it only matters in cases where a direct, uninterrupted, line-of-sight exists between the base station antenna and the UE antenna. In most practical cases, the signal the UE sees (and what the base station sees in the uplink case) is a mixture of signals that have been reflected off of and scattered by all kinds of objects (mountains, buildings, trees, vehicles etc.) in and around the line-of-sight. This is called “multipath”.

In a multipath environment, there is no way to predict the polarization of the signal at the receiving antenna, even if the polarization of the transmitting antenna is well known.

This is why the more complex variants of LTE (CAT.1 and above) require at least two antennas, which are typically set up to be sensitive to signals with different polarization.

Hi @uta, thanks for the tip. You’re right, I was using the wrong APN for the type of SIM I have. I have an easy connect SIM, and for that the APN should be just “iot.t-mobile.nl” it turns out (without the CDP bit). Now the UE attaches & registers to the network perfectly fine 😃

Take this information with a grain of salt until we can get an expert on NB IoT technology to answer this question, but the CE level should be set by the modem based on the measured downlink received signal power and increased automatically when the random access preamble retransmission limit set for the current CE level by the network has been reached.
How long it takes to reach this limit depends on the limit and the period between retries (waiting for the network’s random access response).

@meneerjacco

3GPP and finding the right docs is always challenging and time consuming :-). But once you know the doc number it is well managed and organized to download it:

3GPP document download

I assume you looking for R13 information? The following TS may be interesting

TS36.331

However I have no clue at what power levels the MIBs and SIBs are broadcasted. (afaik you need to sync and collect some info before you can send out the RRC Connection Setup Request)

Maybe somebody else here has more radio experience and knows?

@florian-duecker
Thanks for confirming. I was confused by the information I found in the link (see above)

@Hans-Liefting: Can you please send me the IMEI of your device to support@iotcreators.com? I will check the logs to understand when uplink and downlink messages are received and when downlink messages are sent by the udp server.

Regards, Roland

Dear all,

Thanks to hints from @Kolja-Vornholt , I found a link that with forking works great for me: Sending the input to my parser with socat. All request will now be handled by their own fork.

Example for Linux:

socat -u TCP4-LISTEN:4445,keepalive,reuseaddr,fork STDOUT | php -f /bin/parseTCPdata4445.php

Thanks to this post:
https://stackoverflow.com/questions/44886399/output-a-linux-command-to-a-url-port-or-scocket-instead-of-writing-it-to-a-file/68299500#68299500

Thanks again, @Kolja-Vornholt

@Kolja-Vornholt The problem was as summarized:

I’ve set our modem to band 20-only. I want to use auto-attach (at+cops=0) but it did not find a network However, manual attach (with selecting Vodafone’s network) did work

Doing something else for about 30 minutes around the time @Kolja-Vornholt left the reply about searching the network.
Trying the search only gave me seemingly non-related info (“90104”),
But trying the auto-COPS suddenly did the trick and attached in no time.

So, it doesn’t really seem like a solution yet…

@Adriaan

Well, at least I can reproduce the issue. On the sending side on Linux, the -N flag does the thing.

echo "Hello there" | nc machine.domain <port> -N -v 2>&1

When connecting to a remote host, and using strace -r -f netcat -k -l <port> , setting the -N flag results in

0.000596 read(4, "", 16308) = 0 0.000354 shutdown(4, SHUT_RD) = 0

Without the -N flag, listener remains listening, and hence not closing the connection. This is the last line then:

0.000404 poll([{fd=0, events=POLLIN}, {fd=4, events=0}, {fd=4, events=POLLIN}, {fd=1, events=0}], 4, -1

Next step is that I am going to look if I can change something on the listener side as well.

Greetz,

Adriaan

I try to connect with LTE-M to T-Mobile with a MKR NB 1500 Arduino module. But when I ask for current time from the cellurar module I get the EPoch time that is 4 hours earlier than my local time. Has anyone solver this problem.

#MKRNB1500

As roaming is more or less transparent for the device as well as backend-end server, this recommendation formulated here https://forum.iotcreators.com/topic/594/data-packet-size still applies.

Hi,

Is there a problem with the T-Mobile NBIoT network. Quite some devices having a connection with T-Mobile went offline at night between 26 and 27 April

Thanks,
Thanas