In the field of SMS marketing, and telecommunications in particular, there are many acronyms. Some are well-known and others more obscure, some even resemble each other a lot. To get a clearer picture and better understand the universe that encompasses the use of the SMS communication channel, here is the glossary of the main terms you might encounter.
API (Application Programming Interface)
An API is an interface that allows different servers, software, and/or applications to communicate with each other, therefore to connect their data without the need for manual intervention.
AuC (Authentication Center)
The authentication center allows a mobile phone or smartphone SIM card to authenticate itself on the mobile network.
ETSI (European Telecommunications Standards Institute)
The European Telecommunications Standards Institute is an independent non-profit organization, responsible for developing, testing, and distributing standards for Information and Communication Technologies (ICT) worldwide.
GSM (Global System for Mobile Communication)
GSM is a European mobile telephony standard established by the European Conference of Postal and Telecommunications Administrations (CEPT), then developed by ETSI. The purpose of GSM is to describe the protocols of digital cellular networks used by mobile devices (mobile phones and tablets).
HLR (Home Location Register)
The HLR is the central database of a mobile telephony network, on which all details of the SIM cards of the subscribers of this same network are stored. Each operator has an HLR which allows them to know if people are allowed to use the central GSM network, and to keep track of how calls and messages are sent.
IMEI (International Mobile Equipment Identity)
The IMEI is a number used to uniquely identify each device used on a mobile telephony network, so that the concerned operator can identify the mobile making the call, and allow or deny it to connect. The IMEI number includes between 15 and 17 digits: country of manufacture of the mobile device, serial number of the device, and IMEI code.
IMSI (International Mobile Subscriber Identity)
The IMSI is a unique number allowing a mobile telephony network to identify its subscribers. Each mobile with access to the cellular network has its IMSI. It usually consists of 15 digits (sometimes less): mobile country code (MCC), mobile network code (MNC), and Mobile Subscription Identification Number (MSIN).
MCC (Mobile Country Code)
The MCC refers to the mobile country code. It comes in the form of a unique three-digit number corresponding to the country from which the mobile phone number of a subscriber originates.
MNC (Mobile Network Code)
The mobile network code corresponds to the identifier of a mobile telephone operator in a country. It consists of 2 or 3 digits (2 for North America, 3 for Europe and for most other countries).
MCCMNC
The MNC is associated with the MCC, becoming MCCMNC, in order to uniquely identify a country and a mobile network operator.
MNO (Mobile Network Operator)
The MNO refers to the mobile network operator. It is therefore a company offering mobile services to users (plans, mobile devices,
internet access, etc.).
MVNO (Mobile Virtual Network Operator)
An MVNO is a virtual network operator that does not own its own mobile network or infrastructure, but provides services to subscribers using MNO networks.
MSC (Mobile Switching Center)
The MSC refers to the mobile switching center, which is a piece of mobile telephony equipment handling routing within the network, interconnection with other networks, and call coordination. For example, if a user makes a call and changes coverage area while moving, the MSC transfers the call to the geographically nearest equipment.
MSIN (Mobile Subscriber Identification Number)
The mobile subscriber identification number is a unique number of 9 or 10 digits, appearing at the end of the IMSI. It allows each SIM card to be individually identified. The MSIN includes the area code and the regional/subscriber mobile code.
MSISDN (Mobile Station International Subscriber Directory Number)
The MSISDN, or Mobile Station International Subscriber Directory Number, uniquely identifies a user on a mobile telephony network. In plain terms, it is a person’s phone number. It consists of up to 15 digits: the country of origin code, the mobile network operator code, and the subscriber number assigned by the operator. The MSISDN is defined by ITU recommendation E.164.
PSTN
The Public Switched Telephone Network (PSTN) is a telecommunications network allowing users to verbally communicate with each other from one telephone to another.
SIM (Subscriber Identity Module)
The SIM card, or Subscriber Identity Module, is a smart card placed in mobile phones and allows access to the network. It also allows the secure storage of the IMSI, and for some SIM cards, a user’s personal data, such as contacts and messages for example.
SRIforSM
This is a type of SS7 message sent from one SS7 operator to another, to request details from the recipient network about an MSISDN. The request is sent so that the originating network can know whether the phone number can receive communication, and where to send this communication.
SS7 (Signalling System No. 7)
SS7 refers to a set of signaling protocols used in most of the world’s telephone networks. Its main purpose is to manage fixed and mobile phone calls. It allows users of different networks to communicate with each other.
ITU (International Telecommunication Union)
The International Telecommunication Union is the United Nations agency specialized in the field of information and communication technologies (ICT). Among its main roles, it is responsible for the global allocation of radio frequencies and satellite orbits, the development of technical standards ensuring good interconnection of networks and technologies. It also deals with improving access to ICTs for underserved communities around the world.
UMTS (Universal Mobile Telecommunications System)
Better known as 3G, UMTS is a mobile telephony standard concerning third-generation mobile radio communication systems, standardized by the 3GPP. It allows for a higher data rate on a frequency band.
VLR (Visitor Location Register)
The visitor location register is a temporary database containing real-time information about roaming subscribers in a MSC coverage area. Among the VLR information are the TMSI, the MSRN, the MSC address, and the HLR address. The main purpose of the VLR is to minimize the number of requests that mobile switching centers have to make to the HLR. It also allows for storing information about the cellular network where the SIM card is located geographically.
VoIP
Voice over IP, or Voice over Internet Protocol, is a technology that allows for the transmission and reception of different types of data (calls, videos, text messages, images, etc.) over the internet rather than physical telephone line networks.
