IoT SIM cards vs. regular cellular SIM cards: key differences

Many of us have encountered regular cellular subscriber identity module (“SIM”) cards. When upgrading to a new cell phone, we switch out the SIM card to bring our phone number, billing information, contacts, and saved messages with us. Newer consumer cell phones may also offer “dual SIM” (for having two phone lines) and embedded SIM, or eSIM cards (where the card is not removable and can be updated online).

The growth of the Internet of Things demanded new business applications and operational models, driving the development of specialized SIMS for IoT connectivity. IoT SIM cards are similar to traditional SIMs but don’t require a person to interact with or activate the device. They’re often employed in remote commercial and industrial machinery. In addition to more memory and a longer lifetime than their consumer counterparts, IoT SIMs often need to withstand environmental challenges like vibration, corrosion, humidity, and extreme temperatures. They allow for scaling and updating with minimal disruption. IoT SIM cards enable consolidated management of devices, security maintenance, and reliable data transmission.

Recommended reading: What is the Difference Between SIM Card Types?‍

How cellular SIM cards have changed over time

The first SIM card was developed in 1991 to make the first GSM phone call. These credit card-sized (85mm x 53mm) first-generation SIMs supported up to 128KB of data. The form factor and storage capacity of SIMs evolved as physical phone size shrank and smartphone data needs grew. The Mini-SIM appeared in 1996, the Micro-SIM in 2003, the Nano-SIM in 2012, and most recently, the embedded SIM in 2016, measuring 6mm x 5mm. Today, SIM cards connect billions of devices to global cellular networks.‍

When did IoT SIM cards come into play?

The Internet of Things (IoT) refers to a system of internet-connected physical devices, all collecting and sharing real-time data without human intervention. Although the phrase was coined in 1999, technology took another decade to catch up with the vision. The IoT world required cheap and low-power processors, the adoption of IPv6 for enough IP addresses, and robust access to cellular and wireless networking. By 2025, the number of IoT devices is expected to grow to 42 billion.

Recommended Reading: The Ultimate Guide To The Internet of Things

Key differences between IoT SIM cards and cellular SIM cards

Ultimately, IoT SIM cards serve a different purpose than traditional cellular SIM cards. They connect devices to the cloud, where an IoT management platform aggregates and accesses collected data. In order to efficiently and remotely manage large groups of devices, IoT SIM cards provide more stability, flexibility, and support in the following areas: form factor, robustness & longevity, network connectivity and coverage, data usage, access and security, and management.

Appearance

IoT SIM cards look the same as traditional SIM cards. However, design and usage parameters for IoT devices (especially in healthcare and wearables) often prioritize minimizing size and weight. eSIM technology does not require a SIM card tray and is around half the size (6x5x0.7mm) of a Nano-SIM card (12.3x8.8x0.7mm). This reduces manufacturing costs and plastic waste.

Recommended Reading: What is an eSIM and how is it changing industries?

Robustness & longevity

Robustness and longevity are required for cellular SIMs, but even more so for IoT SIMs. IoT devices may be physically and logistically difficult to access. Industrial-grade removable IoT SIM cards are designed to withstand harsh environmental factors, such as extreme temperatures, humidity, corrosion, vibration, and impact.

An eSIM offers the best solution for hard-to-reach deployments, as it should last for the lifetime of the device and can be reprogrammed remotely. Remote provisioning allows for immediate updates, and eliminates potential physical issues with incompatible SIM card sizes and damage caused by swapping cards.

Network connectivity & coverage

Traditional cellular SIM contracts bind the user to one carrier network, with high roaming charges and rigid contract terms. These SIMs make IoT devices hard to manage at scale, expensive, complex to deploy across different regions, and logistically cumbersome.

IoT SIM cards have enterprise-focused features meant for global operations. A single IoT SIM allows access to multiple local networks, automatically prioritizing the best available connection. IoT contract terms streamline logistics and pricing across countries and networks while allowing flexibility to tailor to specific business usage needs.

Data usage

Traditional cellular SIM contracts structure their pricing tiers based on a fixed volume of data usage.

IoT SIM cards gather and transmit data at different rates — so connectivity service providers typically offer aggregate data packages that are tailored to the specific needs of the company and allow the entire fleet of devices to draw from a single data usage limit. Some IoT devices send small burst data, like updating a smart meter’s temperature sensor measurement. Others might create a huge influx of data traffic, like streaming multiple-angle video surveillance footage. IoT SIM contracts can offer customized data volumes based on each use case. Contracts can also be paused, canceled, and reactivated.

Power consumption

Cellular connectivity has a higher power consumption than other network types, but given the rise of cloud connectivity, IoT systems can off-load SDKs and encryption, reducing the power consumption and improving security. Cellular low-power wide-area networks (LPWAN) designed for IoT (LoRaWAN, NB-IoT, Sigfox) provide energy efficiency, coverage, and cost advantages.

Access & security

Traditional cellular SIM cards assign dynamic IP addresses each time a device establishes a data connection. Remote access requires a VPN client, dynamic DNS services, and private APNs.

IoT SIM cards can be accessed remotely when they are deployed in the field, allowing service personnel to update, troubleshoot, or change configurations.

Removable SIM cards present a risk as they may be taken from one device to equip in another. Other security issues due to flaws in software and encryption may leave IoT data at risk. Even with updateable eSIMs, the device’s physical location remains traceable because the SIM can’t simply be removed. Security and privacy depend on completely deleting user-related data and completely dismantling to disconnect the device.

Management

Smartphones have user interfaces for settings, network status, data usage, and other information, while many IoT devices may not even have screens. IoT network operators need a separate platform to provide insight on network connection, data usage, and other device information, as well as the ability to manage those options. APIs also integrate SIM management capabilities, which increases efficiency and optimization from the device level up to the system level.

Recommended Reading: What is Cellular IoT?

Secure your global cell network with Hologram’s IoT SIM card

Hologram offers Mini, Micro, Nano, and Embedded SIMs. For greater robustness and longevity, our industrial SIMs operate from -40C to 105C, with a minimum of 200M read/write cycles. Our eUICC-capable SIMs can be remotely updated and are available in both triple cut card and MFF2 embedded form factors. Our Hyper SIMs automatically connect to the best available signal across 470 carriers in 200 countries and offer connectivity tools for 2G to 4G LTE, plus new CAT-M and eSIM technologies.

Deploy and manage your IoT fleet with Hologram’s secure, future-proof IoT SIM cards, global network, and a cloud-based dashboard.