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IoT glossary - All things IoT

Cellular IoT is on its way up. And, there are a lot of terms associated with the new technology.

Michael Bratschi
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Cellular IoT is on its way up. And, there are a lot of terms associated with the technology. Here’s a quick rundown of 20 essential cellular IoT terms that will help you better understand cellular IoT technology and the IoT market.

Active Steering

Active steering is a method of controlling a SIM card that enables device owners to specify which networks they want the device to connect to and which networks they don’t want the device to connect to. Active steering requires that the SIM card can be actively controlled while it’s in the device.

Core Network

A core network is the system of highly functional communication facilities that connect primary nodes. In telecom, the core network is the central communications infrastructure. End-users usually connect to the core network through sub-networks, which may or may not be operated by the core network operator.


eNB stands for “Evolved NodeB.” An eNodeB manages radio network resources to optimize communication for devices connected to the LTE network.


The EPC is the “Evolved Packet Core.” The EPC is a major component of the LTE network infrastructure formed by SGWs, PGWs, MMEs, HSS and PCRF.


eSIM stands for “Embedded Subscriber Identity Module.” An eSIM card is built into a device’s mainboard and can be programmed to work with any carrier network. An eSIM replaces a standard SIM card and enables cellular IoT devices to switch carrier networks using software.

Failover Connectivity

Failover connectivity is a backup connection or multiple connections that communications providers use to maintain communications access if their primary connection fails. 3G, 4G, and LTE cellular networks are common choices for failover connectivity.


IIoT is an acronym for the “Industrial Internet of Things.” IIoT is largely made up of devices and sensors that help enable industrial automation, improve quality control and reduce strain on maintenance resources. IIoT is one of the largest markets for IoT devices.


The HSS is the “Home Subscriber Server.” The HSS houses user identification numbers and addresses and user profile information. The HSS also handles network-terminal authentication.

Local Breakout

Local breakout is a method of handling roaming cellular traffic where the traffic is handled by a local operator, rather than tunneling back to the home network.


An MIP is a “Mobile IP address.” MIP is a communications protocol that enables mobile devices to maintain a permanent IP address when they move from one network to another.


An MME is a “Mobile Management Entity.” An MME manages end-user connections to an LTE network. User authentication and authorization, requests for access, and security key information management are all handled by MMEs.


IMSI stands for “International Mobile Subscriber Identity.” It’s a globally unique number that authenticates a device when it connects to a cellular network. Multi-IMSI means that a SIM card is capable of storing multiple IMSI profiles for seamlessly switching between operator networks.

Passive Steering

Passive steering is a method of commanding a SIM card to attach to wireless networks that relies on a priority list of possible networks. The SIM card will attempt to attach to wireless networks according to the priority list.

PCRF Server

The PCRF server is the “Policy and Charging Rules Function Server.” The PCRF server sends quality of service settings information for each user session.


A PGW is a “Packet Gateway.” A PDW provides access to external packet data networks and acts as an IP router that supports mobile-specific signaling protocols and tunneling.

Private LTE

Private LTE is an LTE network designed for a specific enterprise, government, educational or private operations. Private LTE networks can be optimized to perform best in very specific applications with very specific equipment.


A RAN is a “Radio Access Network.” A RAN is a system of radio antennas that provide cellular connectivity for devices within an area. The size of the area depends on the capabilities of the radio antennas. Typically, a RAN is used to connect cellular devices to a core network.

Roaming Operator

A roaming operator is a carrier that operates its own network and has mutually beneficial roaming agreements with other carriers. These agreements enable customers to connect to other operator networks if they are outside the coverage area of the home network or if the home network fails.


An SGW is a “Serving Gateway.” An SGW manages user data packets and acts as an IP router.


UE stands for “user equipment.” UE is the device an end-user uses to connect to an LTE network. Phones, cellular-capable tablets, and LTE compliant USB dongles are common UE.
Cellular IoT terminology is full of acronyms and ultra-technical words. But, learning the core terms will help you grasp many, if not most of the core cellular IoT concepts and principles. Now that you can talk the talk, learn what Telnyx can do for IoT solutions.
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