gobal iot multi-IMSI

What is a Multi-IMSI SIM Card?

Are you looking for a SIM card for any carrier? Multi-IMSI is the solution.

Multi-IMSI may not technically connect to every carrier’s network, but it gives you the option to connect to as many as you need. So, whether you have a device that needs to switch networks as it travels across the United States, or you’re looking for a solution for international connectivity without the cost and headache of roaming, we recommend a multi-IMSI SIM card.

But what is it and how does multi-IMSI work?

IMSI is short for “International Mobile Subscriber Identity.” Every SIM card has at least one of these unique numbers stored on it. 

There are two basic parts. The first identifies the geographic region (i.e. USA, China) and the Mobile Network Operator (MNO), such as Verizon or T-Mobile. Think of it like a routing number; everyone in your region and with your carrier has the same one.

The second part is closer to your account number. It’s unique to you, and it’s what authenticates your subscription so that you can access your MNO’s network alongside any networks with which the MNO has roaming agreements.

Most SIM cards only have one IMSI. Multi-IMSI cards can have as many as you want. It’s like having multiple keys on a ring. As long as the SIM has the right key, it can access the network.

Common use cases for multi-IMSI SIM cards

Businesses use multi-IMSI technology for Internet of Things (IoT) devices that rely on cellular connectivity.

One top use case is for devices that have to operate across wide geographic distances or even multiple countries. Since different carriers offer more or less coverage in different areas, multi-IMSI for IoT keeps the device connected and functional as it travels.

Asset and vehicle trackers are prime examples. If your company needs to keep track of goods or people in transit, loading these trackers with a multi-IMSI solution will help you to maintain visibility.

Emergency response is another common use case. First responders race against the clock to get to the location, set up their operations, and get to work. There’s no time to figure out which MNOs serve the area and which do not.  

By equipping a private cellular network with multi-IMSI, emergency crews can establish the essential communications that they need in a timely manner.

Although, multi-IMSI is for more than just traveling devices. This tech can also provide network failover for any device that relies on cellular connectivity. If one network goes down for any reason, the device will automatically switch to the backup network and stay connected.

Advantages of multi-IMSI over roaming

The main difference between multi-IMSI and roaming is that the latter is a temporary solution. Roaming can work in a pinch—like when you go on vacation for a week or two in a foreign country—but it’s not effective for businesses with devices that regularly need to connect to different cellular networks.

First off, roaming is expensive. Though the charges vary by carrier, it’s not uncommon to see rates around $3/MB of data. Considering that the average cost of cellular data in the US sits around $2.75/GB, roaming is over 1000x more costly.

Second, roaming is subject to regulatory issues. “In some countries, permanent roaming is prohibited by law—the regulatory agencies in some countries limit the amount of time a device can roam on its carriers’ networks,” explains a Twilio whitepaper. These countries include India, Turkey, Brazil, and Canada. This means that businesses operating in these countries will only be able to connect via roaming for a limited amount of time.

Third, roaming capabilities are limited by the home provider. Your primary MNO will determine which foreign networks you can connect to. Many carriers only partner with one network in a given country, and that’s subject to change. Businesses need more control, especially when IoT connectivity is mission-critical.

Finally, there’s no such thing as national roaming. So if, for instance, you need to track an asset as it moves across the US, a single-IMSI SIM card won’t be able to switch between networks as necessary in order to maintain a connection. Since different carriers have different coverage maps, multi-IMSI is the best way to maximize your connectivity options across the country.

Don’t think, however, that roaming and multi-IMSI are completely incompatible. A multi-IMSI SIM card can still roam before switching to a different IMSI profile.

If a device tries to connect to an area with no roaming partners on the approved list, and the MNO associated with the IMSI profile is also not in the area, then the local area will reject the connection. In this case, the SIM will switch to the second IMSI and try the same process. This will repeat until the device successfully establishes a connection.

Final Thoughts

Today’s connected devices are no longer fixed in one place. Modern companies operate across the country and even across the globe, and their IoT devices need to be able to go with them. 

Multi-IMSI SIM cards enable seamless connectivity to multiple carriers within one country or around the world. That makes them ideal for asset and vehicle tracking, establishing temporary networks, and more. 

Ready to unlock the full potential of cellular connectivity for your business? Reach out to Datablaze today to speak with an IoT expert.

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