How does the end of 3G affect your TopView cellular modem?

How does the end of 3G affect your TopView cellular modem?

March 2021, updated October 2021


TopView’s recommended networked cellular modems for SMS/text require a SIM card that registers the modem with a cellular carrier, just like the SIM card in your mobile phone.

Your cellular service through this SIM supports a certain data speed, the most common being the older “3G” speed and a newer data speed named “LTE”.

Many carriers have announced that support for 3G will be ending. How will this affect TopView and your cellular modem?

What determines if a device is using 3G or LTE?

There are multiple factors that determine whether a device is using 3G or LTE.

First, in order to use LTE, the cellular device must support LTE. All of our recommended networked cellular modems support LTE.

Next, your cellular service (your cellular account) must provide an LTE service. Even if you cellular company supports LTE, your account may be a “3G account”. Usually this is easy to change but will require contacting your cellular provider to have the service/account changed to LTE.

If your cellular device supports LTE, and your cellular service/account is LTE, you still may not receive an LTE connection due to your geographic location. If an LTE signal is weak or not available, the device will “downgrade” to a lower connection speed. You may have experienced this on your mobile phone when traveling to a remote area – suddenly you notice slower speeds or “3G” (or lower) in the notification area of your phone.

Do I need LTE/data to send SMS messages?

It depends on the carrier and the type of message. Some carriers require a data plan to send group messages or picture messages (this is not something we do in TopView). Many carriers will send individual SMS messages over the voice network if data is not available.

One of our TopView customers had the following experience: the cellular service/account was 3G, yet the cellular company no longer provided 3G service in his area. Outgoing SMS messages were still successful, but incoming messages were not received. Did outgoing SMS use the voice network, but incoming SMS require data? The carrier upgraded the service/account to LTE and incoming messages started working again.

With one of the cellular services we use internally for testing cellular modems and TopView, the cellular account is required to have data on the plan, and each message uses a small piece of data. Is the data required, or is this just the method that the carrier uses for billing SMS message usage?

The takeaway is this: if you have 3G service for your TopView cellular modem, you may experience issues with SMS as support for 3G ends. The best thing to do now is to verify that you have LTE service on your TopView cellular modem. There are also steps that AT&T LTE customers must perform to ensure continued operation once 3G support ends. More on this below.

Is my cellular modem using 3G or LTE?

Our recommended networked cellular modems have a Web UI used for configuration, testing, and viewing of log files.

This Web UI also allows you to view the current data connection:

  • Log in to the modem Web UI with your browser
  • Select CELLULAR > Radio Status
  • Under Service Information verify that Service shows LTE

If your service is not LTE you should test both outgoing and incoming SMS (if incoming SMS is enabled in TopView) to verify that you can successfully send and receive SMS messages. If this test is not successful, you should contact your carrier to verify that your cellular service/account is LTE. If the service/account is LTE, ask the carrier about LTE support in your area.

If I have LTE Service will the end of 3G affect my modem?

Usually not, but there is one know issue if your service is AT&T. MultiTech has posted 2 PCNs which describes a specific modem configuration change that must be implemented to ensure operation after AT&T sunsets 3G in February 2022.
In October 2021, MultiTech released firmware version 5.3.5 which will make these changes for you.

AT&T users: