Network registeration denied for most of the time

0 votes
Hello all,

We are using Toby L220 for our project.

We  are  giving AT+CREG? at interval of 5 seconds to Toby Module.

AT+CREG contineously giving 0,3 which means registeration denied from network operator.

What to do in such case?

Guide me to handle such situation.


Dhananjay Patil
by dhananjay asked Jun 13, 2018
0 votes
For LTE devices APN has to be set using +UCGDFLT prior to registration process.  Incorrect or blank APN will result in rejection from the network.

Use +CFUN=4 first, set APN using +UCGDFLT second and then use +CFUN=1 to restore modem functionality and start registration.

You need to have APN from SIM provider to do this.
by grumpy answered Jun 13, 2018
Thanks grumpy.
Though we carried out excercise (mention in above post) without setting APN,
 we get AT+CREG? response as 0,3.
The network is saying it doesn't want to play with you, you need to figure out why...

You should be discussing network connectivity with the carrier, not u-Blox
There are numerous reasons a carrier or tower provided might deny you access to the infrastructure.
Invalid SIM, or SIM with no account/authentication behind it.
Your account lacks a roaming agreement with the tower operator.
Your account agreement/settings and usage are at odds.
An IMEI that is not supported or registered with the carrier.
An APN, Username and Password that don't match the account details.
Thanks Clive for valuable input.
Is it advisable to set APN even if SIM card is not registerd with any network or PS services?
CREG Denied strikes me more as an account issue, depending on how things were actually provisioned a front-line call center operator might not be able to remedy if the account or deeper setting where set up incorrectly.

APN will come into play for any data services you might want to access.

The problem you have now is more like the bouncer at the door to a club turning you away because you don't fit the profile.
website banner