![Telephone-keypad](https://upload.wikimedia.org/wikipedia/commons/4/43/Telephone-keypad.svg)
Short Message/Messaging Service, commonly abbreviated as SMS, is a
text messaging
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 devices, desktops/laptops, or another type of compatible comput ...
service component of most
telephone
A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
,
Internet
The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
and
mobile device
A mobile device (or handheld computer) is a computer small enough to hold and operate in the hand. Mobile devices typically have a flat LCD or OLED screen, a touchscreen interface, and digital or physical buttons. They may also have a physica ...
systems. It uses standardized
communication protocols
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchron ...
that let mobile devices exchange short text messages. An intermediary service can facilitate a text-to-voice conversion to be sent to landlines.
SMS technology originated from
radio telegraphy
Wireless telegraphy or radiotelegraphy is transmission of text messages by radio waves, analogous to electrical telegraphy using cables. Before about 1910, the term ''wireless telegraphy'' was also used for other experimental technologies for t ...
in radio memo
pager
A pager (also known as a beeper or bleeper) is a wireless telecommunications device that receives and displays alphanumeric or voice messages. One-way pagers can only receive messages, while response pagers and two-way pagers can also acknow ...
s that used standardized phone protocols. These were defined in 1986 as part of the Global System for Mobile Communications (
GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
) series of standards.
[GSM Doc 28/85 "Services and Facilities to be provided in the GSM System" rev2, June 1985] The first SMS message was sent on 3 December 1992, when Neil Papworth, a test engineer for
Sema Group
Sema Group plc was an Anglo-French IT services company. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index. It was acquired by Schlumberger in 2001.
History
The Company was founded in 1988 by the merger of th ...
, sent "Merry Christmas" to the Orbitel 901 phone of colleague Richard Jarvis.
SMS rolled out commercially on many
cellular networks that decade and became hugely popular worldwide as a method of text communication. By the end of 2010, SMS was the most widely used data application, with an estimated 3.5 billion active users, or about 80% of all mobile phone subscribers.
The service allows users to send and receive messages of up to 160 characters (when entirely alpha-numeric) to and from GSM mobiles. Although most SMS messages are sent from one mobile phone to another, support for the service has expanded to include other mobile technologies, such as
CDMA
Code-division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, where several transmitters can send information simultaneously over a single communicatio ...
networks and
Digital AMPS.
Mobile marketing
Mobile marketing is a multi-channel online marketing technique focused at reaching a specific audience on their smartphones, feature phones, tablets, or any other related devices through websites, e-mail, SMS and MMS, social media, or mobile a ...
, a type of
direct marketing
Direct marketing is a form of communicating an offer, where organizations communicate directly to a pre-selected customer and supply a method for a direct response. Among practitioners, it is also known as ''direct response marketing''. By ...
, uses SMS. The global SMS messaging business was estimated to be worth over
US$
The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...
240 billion in 2013, accounting for almost half of all revenue generated by mobile messaging.
History
Initial concept
Adding text messaging functionality to mobile devices began in the early 1980s. The first action plan of the CEPT Group
GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
was approved in December 1982, requesting that "The services and facilities offered in the public switched telephone networks and public data networks ... should be available in the mobile system." This plan included the exchange of text messages either directly between mobile stations, or transmitted via message handling systems in use at that time.
The SMS concept was developed in the Franco-German GSM cooperation in 1984 by
Friedhelm Hillebrand
Friedhelm Hillebrand is a German engineer who has been influential in setting mobile telecommunications standards. Hillebrand is one of the inventors of the SMS, as he and Frenchman Bernard Ghillebaert created the concept for the service in 1984. ...
and
Bernard Ghillebaert
Bernard Ghillebaert (born 17 January 1952) is a French telecommunications engineer and businessman, and former Chief Executive of Orange UK. He is importantly known for setting the telecommunication standards for text messaging in 1985.
Early life ...
. The GSM is optimized for telephony, since this was identified as its main application. The key idea for SMS was to use this telephone-optimized system, and to transport messages on the
signalling paths needed to control the telephone traffic during periods when no signalling traffic existed. In this way, unused resources in the system could be used to transport messages at minimal cost. However, it was necessary to limit the length of the messages to 128 bytes (later improved to 160 seven-bit characters) so that the messages could fit into the existing signalling formats. Based on his personal observations and on analysis of the typical lengths of
postcard
A postcard or post card is a piece of thick paper or thin cardboard, typically rectangular, intended for writing and mailing without an envelope. Non-rectangular shapes may also be used but are rare. There are novelty exceptions, such as wood ...
and
Telex
The telex network is a station-to-station switched network of teleprinters similar to a telephone network, using telegraph-grade connecting circuits for two-way text-based messages. Telex was a major method of sending written messages electroni ...
messages, Hillebrand argued that 160 characters was sufficient for most brief communications.
SMS could be implemented in every mobile station by updating its software. Hence, a large base of SMS-capable terminals and networks existed when people began to use SMS. A new network element required was a specialized short message service centre, and enhancements were required to the radio capacity and network transport infrastructure to accommodate growing SMS traffic.
Early development
The technical development of SMS was a multinational collaboration supporting the framework of standards bodies. Through these organizations the technology was made freely available to the whole world.
The first proposal which initiated the development of SMS was made by a contribution of Germany and France in the GSM group meeting in February 1985 in Oslo. This proposal was further elaborated in GSM subgroup WP1 Services (Chairman Martine Alvernhe, France Telecom) based on a contribution from Germany. There were also initial discussions in the subgroup WP3 network aspects chaired by Jan Audestad (Telenor). The result was approved by the main GSM group in a June 1985 document which was distributed to industry. The input documents on SMS had been prepared by Friedhelm Hillebrand of
Deutsche Telekom, with contributions from Bernard Ghillebaert of
France Télécom. The definition that Friedhelm Hillebrand and Bernard Ghillebaert brought into GSM called for the provision of a message transmission service of alphanumeric messages to mobile users "with acknowledgement capabilities". The last three words transformed SMS into something much more useful than the electronic paging services used at the time that some in GSM might have had in mind.
SMS was considered in the main GSM group as a possible service for the new digital cellular system. In GSM document "''Services and Facilities to be provided in the GSM System,''"
both mobile-originated and mobile-terminated short messages appear on the table of GSM teleservices.
The discussions on the GSM services were concluded in the recommendation GSM 02.03 "''TeleServices supported by a GSM
PLMN
In telecommunication, a public land mobile network (PLMN) is a combination of wireless communication services offered by a specific operator in a specific country.3GPP TS 21.905 https://www.etsi.org/deliver/etsi_tr/121900_121999/121905/15.00.00_6 ...
.''"
[GSM TS 02.03](_blank)
Teleservices Supported by a GSM Public Land Mobile Network (PLMN). Here a rudimentary description of the three services was given:
# Short message mobile-terminated (SMS-MT)/ Point-to-Point: the ability of a network to transmit a Short Message to a mobile phone. The message can be sent by phone or by a software application.
# Short message mobile-originated (SMS-MO)/ Point-to-Point: the ability of a network to transmit a Short Message sent by a mobile phone. The message can be sent to a phone or to a software application.
# Short message
cell broadcast.
The material elaborated in GSM and its WP1 subgroup was handed over in Spring 1987 to a new GSM body called IDEG (the Implementation of Data and Telematic Services Experts Group), which had its kickoff in May 1987 under the chairmanship of Friedhelm Hillebrand (German Telecom). The technical standard known today was largely created by IDEG (later WP4) as the two recommendations
GSM 03.40 (the two point-to-point services merged) and GSM 03.41 (cell broadcast).
WP4 created a Drafting Group Message Handling (DGMH), which was responsible for the specification of SMS. Finn Trosby of Telenor chaired the draft group through its first 3 years, in which the design of SMS was established. DGMH had five to eight participants, and Finn Trosby mentions as major contributors Kevin Holley, Eija Altonen, Didier Luizard and Alan Cox. The first action plan mentions for the first time the Technical Specification 03.40 "Technical Realisation of the Short Message Service". Responsible editor was Finn Trosby. The first and very rudimentary draft of the technical specification was completed in November 1987. However, drafts useful for the manufacturers followed at a later stage in the period. A comprehensive description of the work in this period is given in.
The work on the draft specification continued in the following few years, where Kevin Holley of Cellnet (now Telefónica O2 UK) played a leading role. Besides the completion of the main specification
GSM 03.40, the detailed protocol specifications on the system interfaces also needed to be completed.
Support in other architectures
The
Mobile Application Part
The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to users. The ...
(MAP) of the
SS7 protocol included support for the transport of Short Messages through the Core Network from its inception.
[MAP phase 1 specification, available from th]
3GPP
web site. MAP Phase 2 expanded support for SMS by introducing a separate operation code for Mobile Terminated Short Message transport.
[MAP phase 2 specification, available from th]
web site. Since Phase 2, there have been no changes to the Short Message operation packages in MAP, although other operation packages have been enhanced to support CAMEL SMS control.
From
3GPP Releases 99 and 4 onwards,
CAMEL Phase 3 introduced the ability for the
Intelligent Network (IN) to control aspects of the Mobile Originated Short Message Service,
[CAMEL Phase 3 specification, available from th]
3GPP
web site. while CAMEL Phase 4, as part of 3GPP Release 5 and onwards, provides the IN with the ability to control the Mobile Terminated service.
[CAMEL Phase 4 specification, also available from the 3GPP specification page.] CAMEL allows the
gsmSCP to block the submission (MO) or delivery (MT) of Short Messages, route messages to destinations other than that specified by the user, and perform real-time billing for the use of the service. Prior to standardized CAMEL control of the Short Message Service, IN control relied on
switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...
vendor specific extensions to the
Intelligent Network Application Part (INAP) of SS7.
Early implementations
The first SMS message
[Hppy bthdy txt!](_blank)
December 2002, BBC News. was sent over the
Vodafone
Vodafone Group plc () is a British multinational telecommunications company. Its registered office and global headquarters are in Newbury, Berkshire, England. It predominantly operates services in Asia, Africa, Europe, and Oceania.
, Vod ...
GSM network in the United Kingdom on 3 December 1992, from
Neil Papworth
Neil Papworth (born 1969) is a British software architect, designer and developer. He is known as the sender of the first ever text message (also known as SMS message) in 1992.
Personal life
Neil Papworth was born on 28 December 1969 in Read ...
of
Sema Group
Sema Group plc was an Anglo-French IT services company. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index. It was acquired by Schlumberger in 2001.
History
The Company was founded in 1988 by the merger of th ...
(now
Mavenir Systems
Mavenir Systems ( NYSE:MVNR ) was a software-based telecommunications networking provider based in Richardson, Texas that existed from 2005 to 2015. The company's software was aimed to deliver internet protocol (IP)-based voice, video, rich commu ...
) using a personal computer to Richard Jarvis of Vodafone using an Orbitel 901 handset. The text of the message was "Merry Christmas."
[UK hails 10th birthday of SMS](_blank)
December 2002, The Times of India.
The first commercial deployment of a
short message service center
A Short Message Service Center (SMSC) is a network element in the mobile telephone network. Its purpose is to store, forward, convert and deliver Short Message Service (SMS) messages.
The full designation of an SMSC according to 3GPP is ''S ...
(SMSC) was by
Aldiscon Aldiscon Limited was a telecommunications software company founded in Dublin, Ireland, in 1988. The company supplied software products to mobile phone operators and became a leader in the supply of short message service centres (SMSC).
History
...
part of
Logica
Logica plc was a multinational IT and management consultancy company headquartered in London and later Reading, United Kingdom.
Founded in 1969, the company had offices in London and in a number of major cities across England, Wales and Scot ...
(now part of
CGI) with Telia (now
TeliaSonera
Telia Company AB is a Swedish multinational telecommunications company and mobile network operator present in Sweden, Finland, Norway, Denmark, Estonia, Latvia and Lithuania.
Telia also owns TV4 Media which includes TV4 in Sweden, MTV Oy in F ...
) in Sweden in 1993, followed by Fleet Call (now
Nextel
Nextel Communications, Inc. was an American wireless service operator that merged with and ceased to exist as a subsidiary of Sprint Corporation, which would later be bought by T-Mobile US and folded into that company. Nextel in Brazil, and forme ...
) in the US, Telenor in Norway and BT Cellnet (now O2 UK) later in 1993. All first installations of SMS gateways were for network notifications sent to mobile phones, usually to inform of voice mail messages.
The first commercially sold SMS service was offered to consumers, as a person-to-person text messaging service by Radiolinja (now part of Elisa) in Finland in 1993. Most early GSM mobile phone handsets did not support the ability to send SMS text messages, and
Nokia
Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational telecommunications, information technology, and consumer electronics corporation, established in 1865. Nokia's main headquarters are in Espoo, Finland, i ...
was the only handset manufacturer whose total GSM phone line in 1993 supported user-sending of SMS text messages. According to
Matti Makkonen Matti Makkonen (16 April 1952 – 26 June 2015) was a Finnish engineer in the field of mobile communications. He was employed (among others) by Nokia Networks and the then Telecom Finland (branded as Tele), as well as Oy. Makkonen played a leadin ...
, an engineer at Nokia at the time, the
Nokia 2010, which was released in January 1994, was the first mobile phone to support composing SMSes easily.
Initial growth was slow, with customers in 1995 sending on average only 0.4 messages per GSM customer per month.
[GSM World press release](_blank)
One factor in the slow takeup of SMS was that operators were slow to set up charging systems, especially for prepaid subscribers, and eliminate billing fraud which was possible by changing
SMSC settings on individual handsets to use the SMSCs of other operators. Initially, networks in the UK only allowed customers to send messages to other users on the same network, limiting the usefulness of the service. This restriction was lifted in 1999.
Over time, this issue was eliminated by switch billing instead of billing at the SMSC and by new features within SMSCs to allow blocking of foreign mobile users sending messages through it. By the end of 2000, the average number of messages reached 35 per user per month,
and on Christmas Day 2006, over 205 million messages were sent in the UK alone.
Text messaging outside GSM
![Landline text messaging](https://upload.wikimedia.org/wikipedia/commons/f/f2/Landline_text_messaging.JPG)
SMS was originally designed as part of GSM, but is now available on a wide range of networks, including
3G networks. However, not all text messaging systems use SMS, and some notable alternative implementations of the concept include
J-Phone
is a Japanese multinational conglomerate holding company headquartered in Minato, Tokyo which focuses on investment management. The Group primarily invests in companies operating in technology, energy, and financial sectors. It also runs th ...
's ''SkyMail'' and
NTT Docomo's ''Short Mail'', both in Japan. Email messaging from phones, as popularized by NTT Docomo's
i-mode
NTT DoCoMo's i-mode is a mobile internet (distinct from wireless internet) service popular in Japan. Unlike Wireless Application Protocols, i-mode encompasses a wider variety of internet standards, including web access, e-mail, and the pa ...
and the
RIM BlackBerry
The blackberry is an edible fruit produced by many species in the genus ''Rubus'' in the family Rosaceae, hybrids among these species within the subgenus ''Rubus'', and hybrids between the subgenera ''Rubus'' and ''Idaeobatus''. The taxonomy ...
, also typically uses standard mail protocols such as
SMTP
The Simple Mail Transfer Protocol (SMTP) is an Internet standard communication protocol for electronic mail transmission. Mail servers and other message transfer agents use SMTP to send and receive mail messages. User-level email clients ty ...
over
TCP/IP
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...
.
SMS today
![SMS messages sent monthly in USA (in billions)](https://upload.wikimedia.org/wikipedia/commons/2/27/SMS_messages_sent_monthly_in_USA_%28in_billions%29.svg)
, 6.1 trillion (6.1 × 10
12) SMS text messages were sent,
which is an average of 193,000 SMS per second. SMS has become a large commercial industry, earning $114.6 billion globally in 2010. The global average price for an SMS message is US$0.11, while mobile networks charge each other interconnect fees of at least US$0.04 when connecting between different phone networks.
In 2015, the actual cost of sending an SMS in Australia was found to be $0.00016 per SMS.
In 2014, Caktus Group developed the world's first SMS-based voter registration system in Libya. As of February 2015 more than 1.5 million people have registered using that system, providing Libyan voters with unprecedented access to the democratic process.
SMS is being increasingly challenged by
Internet Protocol
The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet.
...
-based messaging services such as
RCS,
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, where its wild ancestor, ' ...
's
iMessage
iMessage is an instant messaging service developed by Apple Inc. and launched in 2011. iMessage functions exclusively on Apple platforms: macOS, iOS, iPadOS, and watchOS.
Core features of iMessage, available on all supported platforms, in ...
,
Signal
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing' ...
,
Facebook Messenger
Messenger is a proprietary instant messaging app and platform developed by Meta Platforms. Originally developed as Facebook Chat in 2008, the company revamped its messaging service in 2010, released standalone iOS and Android apps in 2011, and ...
/
WhatsApp
WhatsApp (also called WhatsApp Messenger) is an internationally available freeware, cross-platform, centralized instant messaging (IM) and voice-over-IP (VoIP) service owned by American company Meta Platforms (formerly Facebook). It allows use ...
,
Telegram
Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas ...
,
Viber
Viber, or Rakuten Viber, is a cross-platform voice over IP (VoIP) and instant messaging (IM) software application owned by Japanese multinational company Rakuten, provided as freeware for the Google Android, iOS, Microsoft Windows, Apple macOS ...
,
WeChat
WeChat () is a Chinese instant messaging, social media, and mobile payment app developed by Tencent. First released in 2011, it became the world's largest standalone mobile app in 2018, with over 1 billion monthly active users. WeChat has b ...
(in China) and
Line (in Japan), available on smart phones with internet connections.
SMS Enablement
SMS enablement allows individuals to send an SMS message to a business phone number (traditional landline) and receive a SMS in return. Providing customers with the ability to text to a phone number allows organizations to offer new services that deliver value. Examples include chat bots, and text enabled customer service and call centers.
Technical details
GSM
The ''Short Message Service—Point to Point (SMS-PP)''—was originally defined in GSM recommendation 03.40, which is now maintained in
3GPP as TS 23.040.
GSM 03.41 (now 3GPP TS 23.041) defines the ''Short Message Service—Cell Broadcast (SMS-CB)'', which allows messages (advertising, public information, etc.) to be broadcast to all mobile users in a specified geographical area.
Messages are sent to a
short message service center
A Short Message Service Center (SMSC) is a network element in the mobile telephone network. Its purpose is to store, forward, convert and deliver Short Message Service (SMS) messages.
The full designation of an SMSC according to 3GPP is ''S ...
(SMSC), which provides a "
store and forward
Store and forward is a telecommunications technique in which information is sent to an intermediate station where it is kept and sent at a later time to the final destination or to another intermediate station. The intermediate station, or node in ...
" mechanism. It attempts to send messages to the SMSC's recipients. If a recipient is not reachable, the SMSC queues the message for later retry. Some SMSCs also provide a "forward and forget" option where transmission is tried only once. Both mobile terminated (MT, for messages sent ''to'' a mobile handset) and mobile originating (MO, for those sent ''from'' the mobile handset) operations are supported. Message delivery is "
best effort
Best-effort delivery describes a network service in which the network does ''not'' provide any guarantee that data is delivered or that delivery meets any quality of service. In a best-effort network, all users obtain best-effort service. Under ...
", so there are no guarantees that a message will actually be delivered to its recipient, but delay or complete loss of a message is uncommon, typically affecting less than 5 percent of messages. Some providers allow users to request delivery reports, either via the SMS settings of most modern phones, or by prefixing each message with *0# or *N#. However, the exact meaning of confirmations varies from reaching the network, to being queued for sending, to being sent, to receiving a confirmation of receipt from the target device, and users are often not informed of the specific type of success being reported.
SMS is a
stateless communication protocol in which every SMS message is considered entirely independent of other messages. Enterprise applications using SMS as a communication channel for stateful dialogue (where an MO reply message is paired to a specific MT message) requires that
session management
In computer science and networking in particular, a session is a time-delimited two-way link, a practical (relatively high) layer in the tcp/ip protocol enabling interactive expression and information exchange between two or more communication de ...
be maintained external to the protocol.
Message size
Transmission of short messages between the SMSC and the handset is done whenever using the
Mobile Application Part
The Mobile Application Part (MAP) is an SS7 protocol that provides an application layer for the various nodes in GSM and UMTS mobile core networks and GPRS core networks to communicate with each other in order to provide services to users. The ...
(MAP) of the
SS7 protocol. Messages are sent with the MAP MO- and MT-ForwardSM operations, whose payload length is limited by the constraints of the signaling protocol to precisely 140
byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
s (140 bytes * 8 bits / byte = 1120 bits).
Short messages can be encoded using a variety of alphabets: the default
GSM 7-bit alphabet,
the 8-bit data alphabet, and the 16-bit
UCS-2
The Universal Coded Character Set (UCS, Unicode) is a standard set of characters defined by the international standard ISO/IEC 10646, ''Information technology — Universal Coded Character Set (UCS)'' (plus amendments to that standard), w ...
alphabet.
[3GPP TS 23.038](_blank)
Alphabets and language-specific information. Depending on which alphabet the subscriber has configured in the handset, this leads to the maximum individual short message sizes of 160 7-
bit
The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...
characters, 140 8-bit characters, or 70 16-bit characters. GSM 7-bit alphabet support is mandatory for GSM handsets and network elements,
but characters in languages such as Hindi, Arabic, Chinese, Korean, Japanese, or Cyrillic alphabet languages (e.g., Russian, Ukrainian, Serbian, Bulgarian, etc.) must be encoded using the 16-bit
UCS-2
The Universal Coded Character Set (UCS, Unicode) is a standard set of characters defined by the international standard ISO/IEC 10646, ''Information technology — Universal Coded Character Set (UCS)'' (plus amendments to that standard), w ...
character encoding
Character encoding is the process of assigning numbers to Graphics, graphical character (computing), characters, especially the written characters of Language, human language, allowing them to be Data storage, stored, Data communication, transmi ...
(see
Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, wh ...
).
Routing data and other
metadata is additional to the payload size.
Larger content (
concatenated SMS In the cellular phone industry, mobile phones and their networks sometimes support concatenated short message service (or concatenated SMS) to overcome the limitation on the number of characters that can be sent in a single SMS text message transmis ...
, multipart or segmented SMS, or "long SMS") can be sent using multiple messages, in which case each message will start with a
User Data Header User Data Header (UDH) is a binary structure which may be present at the start of a short message in the Short Message Service in GSM. It does not contain any text, but it specifies how the message should be formatted and processed.
UDH can be use ...
(UDH) containing segmentation information. Since UDH is part of the payload, the number of available characters per segment is lower: 153 for 7-bit encoding, 134 for 8-bit encoding and 67 for 16-bit encoding. The receiving handset is then responsible for reassembling the message and presenting it to the user as one long message. While the standard theoretically permits up to 255 segments, 10 segments is the practical maximum with some carriers, and long messages are often billed as equivalent to multiple SMS messages. In some cases 127 segments are supported, but software limitations in some SMS applications do not permit this. Some providers have offered length-oriented pricing schemes for messages, although that type of pricing structure is rapidly disappearing.
Gateway providers
SMS gateway providers facilitate SMS traffic between businesses and mobile subscribers, including SMS for enterprises, content delivery, and entertainment services involving SMS, e.g. TV voting. Considering SMS messaging performance and cost, as well as the level of messaging services, SMS gateway providers can be classified as aggregators or
SS7 providers.
The aggregator model is based on multiple agreements with mobile carriers to exchange two-way SMS traffic into and out of the operator's
SMSC, also known as "local termination model". Aggregators lack direct access into the SS7 protocol, which is the protocol where the SMS messages are exchanged. SMS messages are delivered to the operator's SMSC, but not the subscriber's handset; the SMSC takes care of further handling of the message through the SS7 network.
Another type of
SMS gateway
An SMS gateway or MMS gateway allows a computer (also known as a Server) to send or receive text messages in the form of Short Message Service (SMS) or Multimedia Messaging Service (MMS) transmissions between local and/or international telecommu ...
provider is based on SS7 connectivity to route SMS messages, also known as "international termination model". The advantage of this model is the ability to route data directly through SS7, which gives the provider total control and visibility of the complete path during SMS routing. This means SMS messages can be sent directly to and from recipients without having to go through the SMSCs of other mobile operators. Therefore, it is possible to avoid delays and message losses, offering full delivery guarantees of messages and optimized routing. This model is particularly efficient when used in mission-critical messaging and SMS used in corporate communications. Moreover, these
SMS gateway
An SMS gateway or MMS gateway allows a computer (also known as a Server) to send or receive text messages in the form of Short Message Service (SMS) or Multimedia Messaging Service (MMS) transmissions between local and/or international telecommu ...
providers are providing branded SMS services with masking but after misuse of these gateways most countries' governments have taken serious steps to block these gateways.
Interconnectivity with other networks
Message Service Centers communicate with the
Public Land Mobile Network (PLMN) or
PSTN
The public switched telephone network (PSTN) provides infrastructure and services for public telecommunication. The PSTN is the aggregate of the world's circuit-switched telephone networks that are operated by national, regional, or local teleph ...
via Interworking and Gateway
MSCs.
Subscriber-originated messages are transported from a handset to a service center, and may be destined for mobile users, subscribers on a fixed network, or
Value-Added Service Providers (VASPs), also known as application-terminated. Subscriber-terminated messages are transported from the service center to the destination handset, and may originate from mobile users, from fixed network subscribers, or from other sources such as VASPs.
On some carriers nonsubscribers can send messages to a subscriber's phone using an
Email-to-SMS gateway. Additionally, many carriers, including
AT&T Mobility,
T-Mobile USA
T-Mobile US, Inc. is an American wireless network operator headquartered in Overland Park, Kansas
Overland Park ( ) is the second-most populous city in the U.S. state of Kansas. Located in Johnson County, Kansas, it is one of four principal ...
,
Sprint, and
Verizon Wireless
Verizon is an American wireless network operator that previously operated as a separate division of Verizon Communications under the name Verizon Wireless. In a 2019 reorganization, Verizon moved the wireless products and services into the div ...
, offer the ability to do this through their respective websites.
For example, an AT&T subscriber whose phone number was 555-555-5555 would receive emails addressed to 5555555555@txt.att.net as text messages. Subscribers can easily reply to these SMS messages, and the SMS reply is sent back to the original email address. Sending email to SMS is free for the sender, but the recipient is subject to the standard delivery charges. Only the first 160 characters of an email message can be delivered to a phone, and only 160 characters can be sent from a phone. However, longer messages may be broken up into multiple texts, depending upon the telephone service provider.
Text-enabled fixed-line handsets are required to receive messages in text format. However, messages can be delivered to non enabled phones using
text-to-speech conversion.
Short messages can send binary content such as
ringtones or logos, as well as
Over-the-air programming
Over-the-air programming (OTA programming) refers to various methods of distributing new software, configuration settings, and even updating encryption keys to devices like mobile phones, set-top boxes, electric cars or secure voice communication ...
(OTA) or configuration data. Such uses are a vendor-specific extension of the GSM specification and there are multiple competing standards, although
Nokia
Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational telecommunications, information technology, and consumer electronics corporation, established in 1865. Nokia's main headquarters are in Espoo, Finland, i ...
's
Smart Messaging is common. An alternative way for sending such binary content is
EMS messaging, which is standardized and not dependent on vendors.
SMS is used for M2M (
Machine to Machine Machine to machine (M2M) is direct communication between devices using any communications channel, including wired and wireless.
Machine to machine communication can include industrial instrumentation, enabling a sensor or meter to communicate th ...
) communication. For instance, there is an LED display machine controlled by SMS, and some
vehicle tracking
A vehicle tracking system combines the use of automatic vehicle location in individual vehicles with software that collects these fleet data for a comprehensive picture of vehicle locations. Modern vehicle tracking systems commonly use GPS or G ...
companies use SMS for their data transport or
telemetry
Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', "remote", an ...
needs. SMS usage for these purposes is slowly being superseded by
GPRS services owing to their lower overall cost. GPRS is offered by smaller telco players as a route of sending SMS text to reduce the cost of SMS texting internationally.
AT commands
Many mobile and satellite
transceiver
In radio communication, a transceiver is an electronic device which is a combination of a radio ''trans''mitter and a re''ceiver'', hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. Thes ...
units support the sending and receiving of SMS using an extended version of the
Hayes command set
The Hayes command set (also known as the AT command set) is a specific command language originally developed by Dennis Hayes for the Hayes Smartmodem 300 baud modem in 1981.
The command set consists of a series of short text strings which can be ...
. The extensions were standardised as part of the GSM Standards and extended as part of the 3GPP standards process.
The connection between the terminal equipment and the transceiver can be realized with a serial cable (e.g.,
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
), a
Bluetooth
Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
link, an
infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
link, etc. Common AT commands include AT+CMGS (send message), AT+CMSS (send message from storage), AT+CMGL (list messages) and AT+CMGR (read message).
However, not all modern devices support receiving of messages if the message storage (for instance the device's internal memory) is not accessible using AT commands.
Premium-rated short messages
Short messages may be used normally to provide
premium rate services to subscribers of a telephone network.
Mobile-terminated short messages can be used to deliver digital content such as news alerts, financial information, logos, and ring tones. The first premium-rate media content delivered via the SMS system was the world's first paid downloadable ringing tones, as commercially launched by Saunalahti (later Jippii Group, now part of
Elisa Group), in 1998. Initially, only Nokia branded phones could handle them. By 2002 the ringtone business globally had exceeded $1 billion of service revenues, and nearly US$5 billion by 2008. Today, they are also used to pay smaller payments online—for example, for file-sharing services, in mobile application stores, or VIP section entrance. Outside the online world, one can buy a bus ticket or beverages from ATM, pay a parking ticket, order a store catalog or some goods (e.g., discount movie DVDs), make a donation to charity, and much more.
The
Value-added service provider (VASP) providing the content submits the message to the mobile operator's SMSC(s) using a
TCP/IP
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...
protocol such as the
short message peer-to-peer protocol
Short Message Peer-to-Peer (SMPP) in the telecommunications industry is an open, industry standard protocol designed to provide a flexible data communication interface for the transfer of short message data between External Short Messaging Entit ...
(SMPP) or the
External Machine Interface (EMI). The SMSC delivers the text using the normal Mobile Terminated delivery procedure. The subscribers are charged extra for receiving this premium content; the revenue is typically divided between the
mobile network operator and the VASP either through revenue share or a fixed transport fee. Submission to the SMSC is usually handled by a third party.
Mobile-originated short messages may also be used in a premium-rated manner for services such as
televoting
Televoting, telephone voting or phone voting is a method of decision making and opinion polling conducted by telephone. Televoting can also extend to voting by SMS text message via a mobile cell phone.
Broadcast contest televoting
Televoting ...
. In this case, the VASP providing the service obtains a
short code
codes, or short numbers, are short digit sequences, significantly shorter than telephone numbers, that are used to address messages in the Multimedia Messaging System (MMS) and short message service (SMS) systems of mobile network operators ...
from the telephone network operator, and subscribers send texts to that number. The payouts to the carriers vary by carrier; percentages paid are greatest on the lowest-priced premium SMS services. Most information providers should expect to pay about 45 percent of the cost of the premium SMS up front to the carrier. The submission of the text to the SMSC is identical to a standard MO Short Message submission, but once the text is at the SMSC, the Service Center (SC) identifies the Short Code as a premium service. The SC will then direct the content of the text message to the VASP, typically using an
IP protocol such as SMPP or EMI. Subscribers are charged a premium for the sending of such messages, with the revenue typically shared between the network operator and the VASP. Short codes only work within one country, they are not international.
An alternative to inbound SMS is based on
long numbers
A long number (e.g. +44 7624 800555 in international notation or 07624 800555 in UK national notation), also known as a virtual mobile number (VMN), dedicated phone number MSISDN or long code, is a reception mechanism used by businesses to receive ...
(international number format, such as "+44 762 480 5000"), which can be used in place of short codes for SMS reception in several applications, such as TV voting, product promotions and campaigns. Long numbers work internationally, allow businesses to use their own numbers, rather than short codes, which are usually shared across many brands. Additionally, long numbers are nonpremium inbound numbers.
Threaded SMS
Threaded SMS is a visual styling orientation of SMS message history that arranges messages to and from a contact in chronological order on a single screen.
It was first invented by a developer working to implement the SMS client for the BlackBerry, who was looking to make use of the blank screen left below the message on a device with a larger screen capable of displaying far more than the usual 160 characters, and was inspired by threaded Reply conversations in email.
Visually, this style of representation provides a back-and-forth chat-like history for each individual contact. Hierarchical-threading at the
conversation-level (as typical in blogs and on-line messaging boards) is not widely supported by SMS messaging clients. This limitation is due to the fact that there is no
session identifier or subject-line passed back and forth between sent and received messages in the
header data (as specified by SMS protocol) from which the client device can properly thread an incoming message to a specific dialogue, or even to a specific message within a dialogue.
Most smart phone text-messaging-clients are able to create some contextual threading of "group messages" which narrows the context of the thread around the common interests shared by group members. On the other hand, advanced enterprise messaging applications which push messages from a remote server often display a dynamically changing reply number (multiple numbers used by the same sender), which is used along with the sender's phone number to create
session-tracking capabilities analogous to the functionality that
cookies
A cookie is a baked or cooked snack or dessert that is typically small, flat and sweet. It usually contains flour, sugar, egg, and some type of oil, fat, or butter. It may include other ingredients such as raisins, oats, chocolate chi ...
provide for web-browsing. As one pervasive example, this technique is used to extend the functionality of many Instant Messenger (IM) applications such that they are able to communicate over two-way dialogues with the much larger SMS user-base. In cases where multiple reply numbers are used by the enterprise server to maintain the dialogue, the visual conversation threading on the client may be separated into multiple threads.
Application-to-person (A2P) SMS
While SMS reached its popularity as a person-to-person messaging, another type of SMS is growing fast: application-to-person (A2P) messaging. A2P is a type of SMS sent from a subscriber to an application or sent from an application to a subscriber. It is commonly used by businesses, such as banks, e-gaming, logistic companies, e-commerce, to send SMS messages from their systems to their customers.
In the US, carriers have traditionally preferred that A2P messages must be sent using a short code rather than a standard
long code
A long number (e.g. +44 7624 800555 in international notation or 07624 800555 in UK national notation), also known as a virtual mobile number (VMN), dedicated phone number MSISDN or long code, is a reception mechanism used by businesses to receive ...
. However, recently multiple US carriers, including Verizon have announced plans to officially support A2P messages over long codes. In the United Kingdom A2P messages can be sent with a dynamic 11 character sender ID; however, short codes are used for OPTOUT commands.
Satellite phone networks
All commercial
satellite phone networks except
ACeS and
OptusSat support SMS. While early
Iridium
Iridium is a chemical element with the symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, it is considered the second-densest naturally occurring metal (after osmium) with a density of ...
handsets only support incoming SMS, later models can also send messages. The price per message varies for different networks. Unlike some mobile phone networks, there is no extra charge for sending international SMS or to send one to a different satellite phone network. SMS can sometimes be sent from areas where the signal is too poor to make a voice call.
Satellite phone networks usually have web-based or email-based SMS portals where one can send free SMS to phones on that particular network.
Unreliability
Unlike dedicated texting systems like the
Simple Network Paging Protocol
Simple Network Paging Protocol (SNPP) is a protocol that defines a method by which a pager can receive a message over the Internet. It is supported by most major paging providers, and serves as an alternative to the paging modems used by many tele ...
and Motorola's ReFLEX protocol, SMS message delivery is not guaranteed, and many implementations provide no mechanism through which a sender can determine whether an SMS message has been delivered in a timely manner.
SMS messages are generally treated as lower-priority traffic than voice, and various studies have shown that around 1% to 5% of messages are lost entirely, even during normal operation conditions, and others may not be delivered until long after their relevance has passed. The use of SMS as an emergency notification service in particular has been questioned.
Vulnerabilities
![SMS Phishing Attack Example](https://upload.wikimedia.org/wikipedia/commons/c/c1/SMS_Phishing_Attack_Example.jpg)
The Global Service for Mobile communications (
GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
), with the greatest worldwide number of users, succumbs to several security vulnerabilities. In the GSM, only the airway traffic between the
Mobile Station
A mobile station (MS) comprises all user equipment and software needed for communication with a mobile network.
The term refers to the global system connected to the mobile network, i.e. a mobile phone or mobile computer connected using a mob ...
(MS) and the
Base Transceiver Station
A base transceiver station (BTS) is a piece of equipment that facilitates wireless communication between user equipment (UE) and a network. UEs are devices like mobile phones (handsets), WLL phones, computers with wireless Internet connectivity, ...
(BTS) is optionally encrypted with a weak and broken
stream cipher (
A5/1 or
A5/2
A5/2 is a stream cipher used to provide voice privacy in the GSM cellular telephone protocol. It was designed in 1992-1993 (finished March 1993) as a replacement for the relatively stronger (but still weak) A5/1, to allow the GSM standard to b ...
). The
authentication
Authentication (from ''authentikos'', "real, genuine", from αὐθέντης ''authentes'', "author") is the act of proving an assertion, such as the identity of a computer system user. In contrast with identification, the act of indicatin ...
is unilateral and also vulnerable. There are also many other security vulnerabilities and shortcomings. Such vulnerabilities are inherent to SMS as one of the superior and well-tried services with a global availability in the
GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
networks. SMS messaging has some extra security vulnerabilities due to its store-and-forward feature, and the problem of fake SMS that can be conducted via the Internet. When a user is roaming, SMS content passes through different networks, perhaps including the Internet, and is exposed to various vulnerabilities and attacks. Another concern arises when an adversary gets access to a phone and reads the previous unprotected messages.
In October 2005, researchers from
Pennsylvania State University published an analysis of vulnerabilities in SMS-capable cellular networks. The researchers speculated that attackers might exploit the open functionality of these networks to disrupt them or cause them to fail, possibly on a nationwide scale.
SMS spoofing
The
GSM
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...
industry has identified a number of potential fraud attacks on mobile operators that can be delivered via abuse of SMS messaging services. The most serious threat is SMS Spoofing, which occurs when a fraudster manipulates address information in order to impersonate a user that has roamed onto a foreign network and is submitting messages to the home network. Frequently, these messages are addressed to destinations outside the home network—with the home SMSC essentially being "hijacked" to send messages into other networks.
The only sure way of detecting and blocking spoofed messages is to screen incoming mobile-originated messages to verify that the sender is a valid subscriber and that the message is coming from a valid and correct location. This can be implemented by adding an intelligent routing function to the network that can query originating subscriber details from the
home location register
Network switching subsystem (NSS) (or GSM core network) is the component of a GSM system that carries out call out and mobility management functions for mobile phones roaming on the network of base stations. It is owned and deployed by mobi ...
(HLR) before the message is submitted for delivery. This kind of intelligent routing function is beyond the capabilities of legacy messaging infrastructure.
Limitation
In an effort to limit telemarketers who had taken to bombarding users with hordes of unsolicited messages, India introduced new regulations in September 2011, including a cap of 3,000 SMS messages per subscriber per month, or an average of 100 per subscriber per day. Due to representations received from some of the service providers and consumers,
TRAI TRAI (Telecom Regulatory Authority of India) is a statutory body set up by the Government of India.
TRAI or Trai may also refer to:
People
Trai is a masculine given name which has its root in Middle English. Notable people with the name include:
...
(Telecom Regulatory Authority of India) has raised this limit to 200 SMS messages per SIM per day in case of
prepaid services, and up to 6,000 SMS messages per SIM per month in case of
postpaid
The postpaid mobile phone is a mobile phone for which service is provided by a prior arrangement with a mobile network operator. The user in this situation is billed after the fact according to their use of mobile services at the end of each mon ...
services with effect from November 1, 2011. However, it was ruled unconstitutional by the Delhi high court, but there are some limitations.
Flash SMS
A Flash SMS is a type of SMS that appears directly on the main screen without user interaction and is not automatically stored in the inbox. It can be useful in
emergencies
An emergency is an urgent, unexpected, and usually dangerous situation that poses an immediate risk to health, life, property, or environment and requires immediate action. Most emergencies require urgent intervention to prevent a worsening ...
, such as a
fire alarm
A fire alarm system warns people when smoke, fire, carbon monoxide or other fire-related or general notification emergency, emergencies are detected. These alarms may be activated automatically from smoke detectors and heat detectors or may also ...
or cases of
confidentiality
Confidentiality involves a set of rules or a promise usually executed through confidentiality agreements that limits the access or places restrictions on certain types of information.
Legal confidentiality
By law, lawyers are often required ...
, as in delivering
one-time password
A one-time password (OTP), also known as a one-time PIN, one-time authorization code (OTAC) or dynamic password, is a password that is valid for only one login session or transaction, on a computer system or other digital device. OTPs avoid seve ...
s.
Silent SMS
In 2010 Germany, almost half a million "silent SMS" messages were sent by the federal police, customs and the secret service "
Verfassungsschutz
The Federal Office for the Protection of the Constitution (german: Bundesamt für Verfassungsschutz or BfV, often ''Bundesverfassungsschutz'') is Germany's federal domestic intelligence agency. Together with the Landesämter für Verfassungss ...
" (offices for protection of the constitution). These silent messages, also known as "silent TMS", "stealth SMS", "stealth ping" or "Short Message Type 0",
are used to locate a person and thus to create a complete movement profile. They do not show up on a display, nor trigger any acoustical signal when received. Their primary purpose was to deliver special services of the network operator to any cell phone.
See also
*
Process driven messaging service A process driven messaging service (PDMS) is a service that is process oriented and exchanges messages/data calls. A PDMS is a service where jobs and triggers can be put together to create a workflow for a message.
Messaging platforms are conside ...
*
Comparison of mobile phone standards
This is a comparison of standards of mobile phones. A new generation of cellular standards has appeared approximately every tenth year since 1G systems were introduced in 1979 and the early to mid-1980s.
Issues
Global System for Mobile Commun ...
*
Instant messaging
Instant messaging (IM) technology is a type of online chat allowing real-time text transmission over the Internet or another computer network. Messages are typically transmitted between two or more parties, when each user inputs text and trigge ...
*
Text messaging
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 devices, desktops/laptops, or another type of compatible comput ...
*
Thumbing
*
GSM 03.40
*
Data Coding Scheme Data Coding Scheme is a one-octet field in Short Messages (SM) and Cell Broadcast Messages (CB) which carries a basic information how the recipient handset should process the received message. The information includes:
* the character set or mess ...
*
Enhanced Messaging Service Enhanced Messaging Service (EMS) was a cross-industry collaboration between Samsung, Ericsson, Motorola, Siemens and Alcatel among others, which provided an application-level extension to Short Message Service (SMS) for cellular phones available on ...
(EMS)
*
Multimedia Messaging Service (MMS)
*
Rich Communication Services
Rich Communication Services (RCS) is a communication protocol between mobile telephone carriers and between phone and carrier, aiming at replacing SMS messages with a text-message system that is richer, provides phonebook polling (for service dis ...
(RCS)
*
Short Message Service Center
A Short Message Service Center (SMSC) is a network element in the mobile telephone network. Its purpose is to store, forward, convert and deliver Short Message Service (SMS) messages.
The full designation of an SMSC according to 3GPP is ''S ...
(SMSC)
*
Short message service technical realisation (GSM) The Short Message Service is realised by the use of the Mobile Application Part (MAP) of the SS7 protocol, with Short Message protocol elements being transported across the network as fields within the MAP messages.Mobile Application Part specifica ...
*
SMS gateway
An SMS gateway or MMS gateway allows a computer (also known as a Server) to send or receive text messages in the form of Short Message Service (SMS) or Multimedia Messaging Service (MMS) transmissions between local and/or international telecommu ...
(sending text to or from devices other than phones)
*
SMS hubbing
SMS hubbing is a new structure for the international flow of SMS between operators, reshaping the way that international mobile inter-operability works by implementing hubs to intermediate the SMS traffic and to offer a larger SMS coverage.
The ...
*
SMS home routing
SMS Home Routing is a modification to the original GSM specifications that changed the way inbound (off-net) SMS messages are treated by mobile telecommunications networks. Adopted by the 3GPP in 2007, Home Routing was devised to enable mobile net ...
*
SMS language
Short Message Service (SMS) language, textism, or textese is the abbreviated language and slang commonly used in the late 1990s and early 2000s with mobile phone text messaging, and occasionally through Internet-based communication such as ema ...
References
External links
3GPP– the organization that maintains the SMS specification
ISO Standards (In Zip file format)GSM 03.38 to Unicode– how the GSM 7-bit default alphabet characters map into Unicode
{{DEFAULTSORT:Sms
3GPP standards
Mobile telecommunication services
Mobile telecommunications standards
Text messaging
Finnish inventions
Mobile phones
Communication