Troubleshooting connectivity

Troubleshooting connectivity

There is a difference between being registered to a network and having data connectivity. Often these two are considered the same.

Network registration means that the SIM is connected to the network and has a decent signal strength. After that you can use Voice/ SMS and Data services right away, For data services, the user needs to ensure correct settings are in place.

The basic settings for data connectivity are:

  • Cellular Data is ON
  • Data Roaming is ON
  • APN is configured correctly

Are you registered to the network?

Check your device for network registration status. On handsets/ tablets the network bars indicate network attach and on IoT devices you can query the network registration via AT commands. A result indicating registered on home network/ roaming is what we are looking for.

Do you have data connectivity? Can you open a PDP context/data session?

This is the process to start a data session from your device on the registered network. If you are having problems, make sure you are registered to the network first. Make sure the device configuration is correct.

Is the APN entered correctly? Does the APN match the active connectivity profile on the SIM?

The APN should be based on your active connectivity profile. It is possible that the SIM has a different active profile from the APN entered in the device.

Do you have data connectivity? Can you open a PDP context/data session?

This is the process to start a data session from your device on the registered network. If you are having problems, make sure you are registered to the network first. Make sure the device configuration is correct.

Are you able to send and receive SMS messages?

Some connectivity providers allow sending SMS to/from the MSISDN of the SIM while some only allow platform to SIM communication. Check which is the case for the connectivity profile on your SIM. Do not update the SMSC (SMS Center) of the SIM from your device - if you did this, you may want to revert to the original value for the connectivity profile.

Are you able to make/receive Voice calls?

Voice calls are not enabled by default. If it isn’t specifically mentioned in your current rate plan, you may need to purchase a different plan for enabling voice.

Is your preferred Radio Access Technology (2G, 3G, 4G, NB-IoT, CAT-M) available?

Make sure your SIM, roaming network and device support the technology you want to use. When checking coverage maps, ensure you filter for the technology as well.

Is your preferred network available in a location?

Coverage maps can be helpful, some free and public resources are available fronPerfCell Mapper, and from the GSMA. There can be areas in general where cellular coverage is weak, e.g. basements, warehouses or remote areas.