ResourcesIoT Glossary Filter by topic Filter by Sector Consumer Energy & Utilities Health ISPs & MSPs IT & Enterprise OEM/Industrial 4.0 Public Sector Retail Smart City Transport and Logistics eUICC & eSIM 5G NB-IoT LTE-M IoT Connectivity IoT Security SIMPro Mapping Sunset IoT Glossary What is a MSISDN?Mobile Station Integrated Services Digital Network (MSISDN) is crucial in ensuring secure connectivity between IoT components. IoT Glossary What is GPRS?General Packet Radio Service (GPRS) is an evolved second-generation cellular network protocol. IoT Glossary What is GSM?Global System for Mobile Communication (GSM) is the technology behind 2G networks. IoT Glossary What is a HLR?Home Location Register (HLR) is a database for managing subscribers on 2G & 3G networks. IoT Glossary What is HSDPA?High Speed Downlink Packet Access (HSDPA) boosted what’s possible on the 3G network. IoT Glossary What are SIM cards?SIM cards are essential for a number of industries, including transport and logistics. IoT Glossary What is 3G?3G was the third generation of mobile technology, and opened the door to data-intensive applications in a range of industries. IoT Glossary What is 4G?4G is the fourth generation of mobile telecommunications technology, and it opened the doors to a number of solutions, including IoT focussed variants such as LTE Cat M, LTE Cat NB and LTE Cat 1. IoT Glossary What is Industry 4.0?Industry 4.0 is the fourth industrial revolution, and has given rise to the smart factory.