In telecommunication, a public land mobile network (PLMN) is a combination of wireless communication services offered by a specific operator in a specific country. A PLMN typically consists of several cellular technologies like

GSM The Global System for Mobile Communications (GSM) is a family of standards to describe the protocols for second-generation (2G) digital cellular networks, as used by mobile devices such as mobile phones and Mobile broadband modem, mobile broadba ...

/ 2G,

UMTS The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. UMTS uses Wideband Code Division Multiple Access, wideband code-division multiple access (W-CDMA) radio access technolog ...

/ 3G,

LTE LTE may refer to: Science and technology * LTE (telecommunication) (Long-Term Evolution), a mobile telephony standard ** LTE Advanced, an enhancement ** LTE Advanced Pro, a further enhancement * Compaq LTE, a line of laptop computers * Leukotrie ...

/ 4G, NR/5G, offered by a single operator within a given country, often referred to as a

cellular network A cellular network or mobile network is a telecommunications network where the link to and from end nodes is wireless network, wireless and the network is distributed over land areas called ''cells'', each served by at least one fixed-locatio ...

PLMN code

A PLMN is identified by a globally unique PLMN code, which consists of a MCC (Mobile Country Code) and MNC (Mobile Network Code). Hence, it is a five- to six-digit number identifying a country, and a mobile network operator in that country, usually represented in the form 001-01 or 001–001. A PLMN is part of a: * Location Area Identity (LAI) (PLMN and Location Area Code) * Cell Global Identity (CGI) (LAI and Cell Identifier) * IMSI (see PLMN code and IMSI)

Leading zeros in PLMN codes

Note that an MNC can be of two-digit form and three-digit form with leading zeros. It is administered by the respective national numbering plan administrator.ITU-T Rec. E.212 (09/2016), section 3.4 mobile network code (MNC) From PLMN assignments, it is apparent that such dualities of two-digit and three-digit MNCs with the same number value are avoided (see the list of mobile country codes and mobile network codes). An example for an actual three-digit/two-digit MNC with leading zeros is in Bermuda MCC, 350-007 and 350-00, 350-01.

PLMN code and IMSI

The IMSI, which identifies a SIM or USIM for one subscriber, typically starts with the PLMN code. For example, an IMSI belonging to the PLMN 262-33 would look like 262330000000001. Mobile phones use this to detect

roaming Roaming is a wireless Wireless communication (or just wireless, when the context allows) is the transfer of information (''telecommunication'') between two or more points without the use of an electrical conductor, optical fiber or oth ...

, so that a mobile phone subscribed on a network with a PLMN code that mismatches the start of the USIM's IMSI will typically display an "R" on the icon that indicates connection strength.

PLMN services

A PLMN typically offers the following services to a mobile subscriber: * Emergency calls to local Fire/Ambulance/Police stations. * Voice calls to/from any PLMN ("cellular network") or

PSTN The public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telephony. The PSTN consists ...

landline A landline is a physical telephone connection that uses metal wires or optical fiber from the subscriber's premises to the network, allowing multiple phones to operate simultaneously on the same phone number. It is also referred to as plain old ...

VoIP Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as ...

). *

Short message service Short Message Service, commonly abbreviated as SMS, is a text messaging service component of most telephone, Internet and mobile device systems. It uses standardized communication protocols that let mobile phones exchange short text messages, ...

(SMS) services to/from any PLMN or SIP service (the original form of

texting Text messaging, or texting, is the act of composing and sending electronic messages, typically consisting of alphabetic and numeric characters, between two or more users of mobile phones, tablet computers, smartwatches, desktops/laptops, or ...

on a mobile phone, now often replaced by

Messaging apps Instant messaging (IM) technology is a type of synchronous computer-mediated communication involving the immediate ( real-time) transmission of messages between two or more parties over the Internet or another computer network. Originally involv ...

). *

Multimedia Messaging Service Multimedia Messaging Service (MMS) is a standard way to send messages that include multimedia content to and from a mobile phone over a cellular network. Users and providers may refer to such a message as a PXT, a picture message, or a multimedia ...

(MMS) services to/from any PLMN or SIP service. *

Unstructured Supplementary Service Data Unstructured Supplementary Service Data (USSD), sometimes referred to as "quick codes" or "feature codes", is a communications protocol used by GSM cellular telephones to communicate with the mobile network operator's computers. USSD can be use ...

(USSD) for operator specific interactions (e.g. dialing "*#100#" to indicate the current balance). * Internet data connectivity for arbitrary services, e.g. via

GPRS General Packet Radio Service (GPRS), also called 2.5G, is a mobile data standard on the 2G cellular communication network's Global System for Mobile Communications, global system for mobile communications (GSM). Networks and mobile devices wit ...

, IuPS in

, or

. The availability, quality and bandwidth of these services strongly depends on the particular technology used to implement a PLMN.

References

{{Mobile telecommunications standards Mobile technology