GMLC Gateway Glossary

Public Land Mobile Network (PLMN)

Any wireless communications network designed for use by customers in cars or on foot is referred to as a public land mobile network (PLMN). A PLMN is often made up of various cellular technologies, such as GSM/2G, UMTS/3G, and LTE/4G, offered by a single operator inside a certain country.


SIGTRAN (Signaling Transport Working Group) is a group of protocols for transporting telecom signaling messages over IP. The telco switch sends SS7 signals to a signaling gateway (SG), transforming them into SIGTRAN packets. 

HLR (Home Location Register)

An HLR (Home Location Register) is a database used to manage subscribers on 2G and 3G networks. The database contains information about every active mobile network user, including their phone number, service eligibility, and history of number porting.

HSS (Home Subscriber Server)

A Home Subscriber Server (HSS) is an all-inclusive management tool for subscriber data and includes subscriber information, device profile, and state information. It was created to support GSM, UMTS, LTE, IMS, WiFi, and IoT network mobility management, authentication, and authorization needs.

VMSC (Visited Mobile Switching Center)

The Mobile Switching Center (MSC) serving a mobile in the VPLMN (Visited Public Land Mobile Network) is referred to as the Visited Mobile Switching Center.

SGSN (Serving GPRS Support Node)

The SGSN, which is a component of the GPRS infrastructure, offers switching capabilities, security, and authentication for GPRS users via the HLR. The GGSN, HLR, and PCU are the SGSN's three main interfaces.

MSC (Mobile Switching Center)

The core of a network switching subsystem (NSS) is a mobile switching centre (MSC).  The MSC is mostly used for communications switching operations such call setup, release, and routing.

MME (Mobility Management Entity)

An important part of the LTE Evolved Pack Core (EPC) is the Mobility Management Entity (MME). It facilitates subscriber authentication, roaming, and network handovers while providing mobility session management for the LTE network.


Mobile application part is an SS7 protocol that provides an application layer for the nodes in GSM, UMTS, and GPRS networks. It is used for setting up and controlling wireless calls over the public switched telephone network. 


The phone number used to identify a device during conversations or data sessions on a cellular network is called the MSISDN (Mobile Station Integrated Services Digital Network). It plays a critical role in maintaining safe connectivity amongst the various IoT network components.


Each base transceiver station (BTS) or sector of a BTS inside an area code is identified by a unique number called a GSM Cell ID (CID).


A Mobile Switching Center (MSC) is an essential component of the GSM/CDMA network architecture. It serves as the network switching subsystem's (NSS) command centre.

JAIN-SLEE platform

The Java open standard for an SLEE is called JAIN SLEE (Service Logic Execution Environment). It is an API for creating and deploying network services in the Java programming language.

External Short Messaging Entity

An application known as an External Short Messaging Entity (ESME) can send and/or receive SMS messages by establishing a connection with a Short Message Service Center (SMSC).

Start innovating with Mobius

What's next? Let's talk!

Mobius Software

As a company you'll get:

  • Get started quickly

  • Support any business model

  • Join millions of businesses