You don’t have to be a software engineer to understand the Internet of Things. Below you’ll find simple, non-technical explanations of key IoT concepts you need to know.
What Is a TAC Number? Type Allocation Codes Explained
26.07.2022 TAC numbers help cellular networks recognize devices that are approved to access network infrastructure. While it doesn’t identify individual devices (the IMEI number does this) or individual SIMs (that’s the ICCID number), it communicates the make and model and confirms that it meets regional standards and specifications.
What Is HLR? Home Location Register Explained
Home Location Registers are a component of 2G and 3G mobile networks. Every cellular carrier that facilitates telecommunications on one of these networks maintains its own HLR. Instead of an HLR, 4G networks have a Home Subscriber Server (HSS). In 5G networks, Unified Database Management (UDM) performs these functions.
What Is an MSISDN?
The abbreviation MSISDN is a little ambiguous. Major telecommunications organizations and standardization bodies have slightly different terms with this same abbreviation, but they all represent the same thing. Depending on the source and context, MSISDN can stand for:
What Is an International Mobile Subscriber Identity (IMSI)?
IMSI numbers are usually 15 digits, and they have three distinct parts:
What Is Multi-IMSI and How Does It Work?
An IMSI is a key component of a Subscriber Identity Module (SIM) profile, which is stored on a SIM card. Each one allows a device to connect to a limited number of networks. When a SIM card holds multiple IMSIs, it enables subscribers to switch carriers as needed and connect to significantly more networks.
What Is an ICCID Number?
Mobile Network Operators (MNOs) use ICCID numbers to determine which network to connect a subscriber to. Unlike an IMEI number, which refers to the mobile device, an ICCID number refers to the SIM card itself. Since each SIM card has a unique ICCID, you may sometimes hear it called the SIM card number.
What is an IMEI number?
A serial number that the manufacturer assigns to cellular devices. Just as people have their own ID number and every car has a vehicle number, every cellular device with a SIM card can be precisely identified by a so-called IMEI number – International Mobile Equipment Identity. The 15-digit number is guaranteed to be globally unique, meaning dual SIM devices have two IMEI numbers due to their two SIM card slots. To learn more about other cellular connectivity and SIM card identifiers, check out our previous blog on this topic which explains what the ICCID and IMSI numbers are.