eSIM – What Is All the Excitement About?

Apr 7, 2023


Everyone has heard of SIM cards. The SIM, short for Subscriber Identity Module, holds your digital credentials for wireless network access. These credentials, known as IMSIs (International Mobile Subscriber Identity), enable each SIM to securely identify itself and connect to a wireless network. In the United States, 95% of SIM cards contain only one set of credentials, allowing them to connect to their local wireless carrier. Wireless carriers prefer this type of SIM because it gives them control over which networks a device can use in the US and globally, allowing them to direct traffic to a specific roaming network that offers the best rate.

Around 15 years ago, SIM technology began to evolve, enabling multiple sets of credentials/IMSIs to be installed on a single SIM. These Multi-IMSI SIMs have an application that selects the available IMSI on the SIM based on its location. Suddenly, a single SIM could connect to hundreds of networks worldwide by using multiple IMSIs, eliminating the limitation of being tied to a specific carrier. In 2007, Globalgig introduced its first Multi-IMSI SIM, which now provides connectivity to over 600 networks in 200+ countries/regions.

However, the Multi-IMSI SIM had a few drawbacks. 

SIM Carriers Are “Baked In”

First, once a Multi-IMSI SIM left the factory with a portfolio of IMSIs, that portfolio could never change. In other words, the carriers that are accessible via the SIM are “baked in”. Therefore, if a new network with better pricing or more coverage became available, you would have to swap out your Multi-IMSI SIM with a new one that has the IMSIs required to access this new network. This represents a significant logistical challenge, particularly for customers with a large number of deployed SIMs who need access to the new network.


The second drawback is the cost. IMSIs are not free. While having access to a Multi-IMSI SIM is a good fit for mobile applications where the SIM frequently moves from country to country, a Multi-IMSI SIM is not optimal for stationary devices where the device remains in a single country. If the use-case for the SIM is stationary, the majority of the IMSIs are never used, and they can’t be used by another SIM, which results in wasted IMSIs.

eSIM is designed to overcome the drawbacks of the Multi-IMSI SIM by optimizing wireless connectivity through the dynamic use of IMSIs. Imagine that wherever the eSIM is deployed, it will download the most optimized credential/IMSI for that location. If the eSIM is mobile, it will always use the best IMSI for that country. Most importantly, if the “best” IMSI changes next month, not to worry, the eSIM will download the new IMSI automatically!

How It Works

Globalgig’s eSIM has a digital communication channel back to our Orchestra SIM Management platform. The eSIM uses that channel to communicate changes in its location, serving network, and the device it is inserted in. In addition, once a day or so, the IMSI checks in with Orchestra to see if there is a new, better IMSI that it should use at its current location. Each day, Orchestra will determine the best credential/IMSI to use, AND when a new IMSI is available, it will send it over-the-air to the eSIM.

With eSIM, Globalgig clients will have access to the most optimized and up-to-date networks immediately and will never again need to swap out a SIM. Each eSIM will have dynamic access, via our Orchestra platform, to our entire library of IMSIs, currently covering 200+ countries/regions with access to 600+ carriers. Each eSIM will not only have more choices when it comes to connectivity, but Globalgig will also leverage this flexibility to optimize data rate plans based on our clients’ specific requirements.

Globalgig’s eSIM functionality is not just for embedded eSIMs. Our eSIM functionality can be used anywhere you would use a traditional SIM. We offer our eSIM in the 2FF, 3FF, or 4FF SIM form factors, as well as a soldered chip for IoT devices.

Still have questions about how our eSIM solution can work for you?