Cellular connectivity remains among the most popular connectivity options in various IoT deployments, connecting billions of interconnected IoT devices all over the world.
A key advantage of cellular connectivity over other IoT connectivity options is its widest coverage area. Along with satellite technology, cellular connectivity is the only two connectivity solutions at the moment that are capable of global connectivity: connecting two or more devices that are separated halfway across the world.
However, it’s not saying that cellular connectivity is a perfectly ideal solution in all IoT use cases. The fact that most cellular connectivity still relies on SIM cards to connect to the respective network provider remains one of its key weaknesses, and this is where M2M SIM cards come in.
What Are the M2M SIM Cards?
What actually is an M2M SIM Card? What are the differences compared to standard SIM cards? In fact, many IoT users don’t really understand the necessity of M2M SIMs in IoT deployments
M2M stands for Machine to Machine, referring to how IoT devices send and receive data directly between each other, which allows us to automate virtually any process and eliminate the necessity of human supervision and interaction.
So, an M2M SIM card is, simply put, a SIM card specially designed for M2M connectivity in IoT deployments. M2M Sim cards offer various critical features and functionalities that aren’t available in standard SIM cards, as we will discuss below.
M2M SIM Cards VS Standard SIM Cards
There are four key advantages provided by M2M SIM cards that aren’t available in standard SIM cards, namely:
Centralized Provisioning and Management
Traditional mobile SIM cards, for example, those in our smartphones, are designed only to serve and manage connectivity for a single device.
IoT deployments, however, can involve a lot of interconnected devices, probably in the hundreds or even thousands, so we’ll require a centralized system where we can provision, monitor, and control all these interconnected SIMs in a single dashboard.
M2M SIMs, together with management software from IoT network providers can allow IoT operators to monitor the interconnected devices in a single dashboard.
Durability and Longevity
Standard SIM cards are only designed for normal day-to-day device usage, and will only last for around a couple of years of normal usage before you’ll need a replacement SIM card from the network provider.
This is not ideal for IoT projects, where IoT sensors and devices are often deployed in remote areas with extreme conditions (extreme hot/cold temperature, vibrations, etc.). M2M SiM cards, however, are designed for more durability and depending on the form factor, can last for up to a decade even in extreme environments.
With data becoming the most valuable asset for many individuals and businesses, data security is becoming a serious concern in various IoT projects. IoT devices can send and receive a massive amount of data every day, and if they aren’t thoroughly protected.
M2M SIM cards are designed for better data security. M2M SIM cards can offer fixed IP addresses allowing us to access any devices more securely and reliably regardless of location. Some M2M SIM cards might also be specially programmed to securely access APN (Access Point Name), so no one can’t connect to your IoT devices without knowing the credential to access your APN.
Data Plan Aggregation
M2M SIM cards allow us to aggregate data plans across your SIM estate, which is a really important factor especially in large-scale IoT projects involving a lot of interconnected devices.
It’s common in IoT deployments to have some devices overusing data, while some others are under-using, and without aggregation, we can end up spending too much on data plan costs.
With M2M SIM cards and IoT-specific data plans, every new device (and new SIM) added to the IoT network will increase the data cap, maximizing the scalability and cost-efficiency of the project.
eSIM VS M2M SIM: Different SIM Form Factors
A very common misconception in cellular IoT connectivity is to think that “M2M SIM” and “eSIM” are one and the same.
eSIM, or embedded SIM, is actually one of several form factors available for any SIM card (including M2M SIMs), and while eSIMs are now often used in various IoT deployments, not all eSIMs are M2M in nature.
M2M SIMs are available in several different form factors (shapes and sizes:
- Full-Size (1FF) SIM: about the same size as your credit card. Very rarely used in any devices at the moment, as most devices prefer smaller form factors.
- Mini (2FF) SIM: 25mm x 15mm x 0.76mm in size, the industry-standard SIM card size, still used in older smartphones, and in IoT projects, they are often used in vehicles, vending machines, and other bigger IoT devices.
- Micro (3FF) SIM: around half the size of 2FF SIMs, used in most smartphones and tablets nowadays, and also in various IoT devices.
- Nano (4FF) SIM: around 40% smaller than 3FF SIMs, commonly used in smaller wearables and IoT devices. However, 4FF SIMs are typically not very durable so they aren’t recommended for harsh environments.
- eSIM (MFF2): Embedded SIM is not a plastic SIM card, but a 6mm x 5mm x 1mm chip integrated into the device’s body. At the moment it is the most popular M2M SIM due to its durability and versatility.
Cellular IoT connectivity with M2M SIM cards is the most common connectivity solution used in a wide range of IoT projects all around the world. M2M SIM cards offer the widest coverage area at the moment and are relatively cost-effective compared to other IoT connectivity solutions.