Short Message Service or Silent Messaging Service (
SMS) is a communication service standardized in the GSM mobile communication system, using standardized communications protocols allowing the interchange of short text messages between
mobile telephone devicesA mobile phone or mobile is a long-range, electronic device used for mobile telecommunications...
. SMS text messaging is the most widely used data application on the planet, with 2.4 billion active users, or 74% of all mobile phone subscribers sending and receiving text messages on their phones. The SMS technology has facilitated the development and growth of
text messagingText messaging, or texting, is a colloquial term referring to the exchange of brief written messages between mobile phones, over cellular networks. While the term most often refers to messages sent using the Short Message Service , it has been extended to include messages containing image, video,...
. The connection between the phenomenon of text messaging and the underlying technology is so great that in parts of the world the term "SMS" is used as a synonym for a text message or the act of sending a text message, even when a different protocol is being used.
SMS as used on modern handsets was originally defined as part of the
GSMGSM is the most popular standard for mobile phones in the world. Its promoter, the GSM Association, estimates that 80% of the global mobile market uses the standard...
series of standards in 1985 as a means of sending messages of up to 160 characters (including spaces), to and from GSM mobile handsets. Since then, support for the service has expanded to include other mobile technologies such as
ANSI CDMA networksInterim Standard 95 is the first CDMA-based digital cellular standard pioneered by Qualcomm. The brand name for IS-95 is cdmaOne. IS-95 is also known as TIA-EIA-95....
and
Digital AMPSIS-54 and IS-136 are second-generation mobile phone systems, known as Digital AMPS . It was once prevalent throughout the Americas, particularly in the United States and Canada...
, as well as satellite and
landlineA landline, main line or fixed-line is a telephone line which travels through a solid medium, either metal wire or optical fibre. This is distinguished from a mobile cellular line, where the medium used is the airwaves...
networks. Most SMS messages are mobile-to-mobile text messages, though the standard supports other types of broadcast messaging as well.
Initial concept
The idea of adding text messaging to the services of mobile users was latent in many communities of mobile communication services at the beginning of the 1980s. The first action plan of the CEPT Group GSM approved in December 1982 requested "The services and facilities offered in the public switched telephone networks and public data networks ...should be available in the mobile system". This target includes the exchange of text messages either directly between mobile stations or the transmission via Message Handling Systems widely in use since the beginning of the 1980s.
The innovation in SMS is indicated by the word
Short in Short Message Service. The GSM system is optimized for telephony, since this was identified as its main application. The key idea for SMS was to use this telephony-optimized system and to transport messages on the signaling paths needed to control the telephony traffic during time periods when no signaling traffic existed. In this way unused resources in the system could be used to transport messages without additional cost. However, it was necessary to limit the length of the messages to 128 bytes (later improved to 140 bytes, or 160 7-bit characters), so that the messages could fit into the existing signaling formats. Therefore the service was named “
Short Message Service”.
This concept allowed implementing the SMS in every mobile station with additional software routines. A new network element required was a specialised Short Message Service Centre, as well as enhancement to the radio capacity and network transport infrastructure. It needed capacity expansions of course with growing SMS traffic. This concept was instrumental for the implementation of SMS in every mobile station ever produced and in every network from early days on. Hence a large base of SMS capable terminals and networks existed when the users began to utilise the SMS.
Early development
No individual expert or company can claim to be the ‘father’ or ‘creator’ of the SMS. The GSM project as a whole was indeed a multi-national collaboration at its best. Therefore the responsibility for the SMS innovation is not with a single person but with a network of closely cooperating persons who have created this innovation. They did this with the supporting framework of Standard Bodies and through these organisations made the technology freely available to the whole world. This is described and supported by evidence in the following sections.
The first proposal for SMS which initiated the development of SMS in the group GSM was made by a contribution of Germany and France into the GSM 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 group GSM in a document of June 85 which was distributed to industry. The input documents on SMS had been prepared by Friedhelm Hillebrand (
Deutsche TelekomDeutsche Telekom AG is a telecommunications company headquartered in Bonn, Germany. It is the largest telecommunications company in Europe....
) with contributions from Bernard Ghillebaert (
France TélécomFrance Télécom is the main telecommunications company in France, the third-largest in Europe and one of the largest in the world. It currently employs about 191,000 people and has nearly 159 million customers worldwide . In 2008 the group had revenue of €53.5 billion...
).
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 then concluded in the recommendation GSM 02.03 "
TeleServices supported by a GSM PLMNIn telecommunication, a public land mobile network is a network that is established and operated by an administration or by a recognized operating agency for the specific purpose of providing land mobile telecommunications services to the public....
". 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
Cell Broadcast messaging is a mobile technology feature defined by the ETSI’s GSM committee and is part of the GSM standard.It is also known as Short Message Service - Cell Broadcast ....
.
The material elaborated in GSM and its subgroups WP1 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 together) and GSM 03.41 (cell broadcast).
WP4 created a drafting group message handling (DGMH) who was responsible for the specification of SMS. It was chaired by Finn Trosby (Telenor). DGMH had about 5 to 8 participants (Finn Trosby mentions as contributors Alan Cox of Vodafone). 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 draft of the technical specification was completed in November 1987. A comprehensive description.
The work on the draft specification continued in the following few years, where Kevin Holley of Cellnet (now O2) played a leading role. Besides the completion of the main specification GSM 03.40 also the detailed protocol specifications on the system interfaces needed to be completed.
Support in other architectures
The
Mobile Application PartThe Mobile Application Part is an SS7 protocol which 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 mobile phone users...
(MAP) of the SS7 protocol included support for the transport of Short Messages through the Core Network from its inception. MAP Phase 2 expanded support for SMS by introducing a separate operation code for Mobile Terminated Short Message transport. 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
3GPPThe 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, to make a globally applicable third generation mobile phone system specification within the scope of the International Mobile Telecommunications-2000 project of the International...
Releases 99 and 4 onwards,
CAMELCustomised Applications for Mobile networks Enhanced Logic, or CAMEL for short, is a set of standards designed to work on either a GSM core network or UMTS network. They allow an operator to define services over and above standard GSM services/UMTS services...
Phase 3 introduced the ability for the
Intelligent Network (IN)The Intelligent Network, typically stated as its acronym IN, is a network architecture intended both for fixed as well as mobile telecom networks...
to control aspects of the Mobile Originated Short Message Service, 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 allows the
gsmSCPA service control point is a standard component of an intelligent network telephone system which is used to control the service. Standard SCPs in the telecom industry today are deployed using SS7, Sigtran or SIP technologies. The SCP queries the service data point which holds the actual...
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 vendor specific extensions to the
Intelligent Network Application Part (INAP)The Intelligent Network Application Part is a signalling protocol used in the intelligent network architecture. It is part of the SS7 protocol suite, typically layered on top of TCAP.It can also be termed as logic for controlling telecommunication services migrated from traditional switching...
of SS7.
Early implementations
The first SMS message was sent over the
VodafoneVodafone is a British mobile network operator, with its headquarters in Newbury, Berkshire, England, UK. It is the largest mobile telecommunications network company in the world by turnover, and has a market value of about £75 billion...
GSM network in the
United KingdomThe United Kingdom of Great Britain and Northern Ireland is a sovereign state located off the northwestern coast of continental Europe. It is an island country, spanning an archipelago including Great Britain, the northeastern part of Ireland, and many small islands...
on 3 December 1992, from Neil Papworth of
Sema GroupSema 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 but was acquired by Schlumberger in 2001.-History:...
(now
Airwide SolutionsAirwide Solutions is a privately-held United States-based mobile messaging and wireless internet infrastructure company.The company was founded in 2004 through the merger of Taral Networks and Schlumberger's Messaging Solutions unit, formerly Sema Group...
) using a personal computer to Richard Jarvis of Vodafone using an
OrbitelOrbitel is Bulgarian wireline telecommunications and Internet service provider with national licenses for voice and data. Through its national packet-switched network Orbitel provides convergent telecommunication solutions for telephony, high speed Internet and VPNs throughout Bulgaria...
901 handset. The text of the message was "Merry Christmas". The first SMS typed on a GSM phone is claimed to have been sent by Riku Pihkonen, an engineering student at
NokiaNokia Corporation is a Finnish multinational communications corporation that is headquartered in Keilaniemi, Espoo, a city neighbouring Finland's capital Helsinki...
, in 1993.
The first commercial deployment of a Short Message Service Centre (SMSC) was by
AldisconAldiscon was a telecommunications software company founded in Dublin, Ireland in 1988. The company was an innovator in supplying software products to the mobile sector and became a market leader in the supply of Short Message Service Centre's to mobile operators globally.Aldiscon invented SMPP,...
(now Acision) with
TeliaSoneraTeliaSonera AB is the dominant telephone company and mobile network operator in Sweden and Finland. The company just launched fiber broadband in Denmark, and is also active in other countries in Northern, Eastern Europe, Central Asia and Spain, with a total of 106 million mobile customers...
in Sweden in 1993,, followed by Fleet Call (now Nextel) in the US, Telenor in Norway and BT Cellnet (now O2 UK) later in 1993.
Initial growth was slow, with customers in 1995 sending on average only 0.4 messages per GSM customer per month. 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
SMSCA Short Message Service Center is a network element in the mobile telephone network which delivers SMS messages.-Operation:When a user sends a text message to another user, the message gets stored in the SMSC which delivers it to the destination user when they are available...
settings on individual handsets to use the SMSCs of other operators.
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 by Christmas Day 2006, over 205m texts were sent in the UK alone.
It is also alleged that the fact that roaming customers, in the early days, rarely received bills for their SMSs after holidays abroad had a boost on text messaging as an alternative to voice calls.
Text messaging outside GSM
SMS was originally designed as part of GSM, but is now available on a wide range of networks, including
3GInternational Mobile Telecommunications-2000 , better known as 3G or 3rd Generation, is a family of standards for mobile telecommunications defined by the International Telecommunication Union, which includes GSM EDGE, UMTS, and CDMA2000 as well as DECT and WiMAX...
networks. However, not all text messaging systems use SMS, and some notable alternate implementations of the concept include J-Phone's
SkyMail and
NTT Docomois the predominant mobile phone operator in Japan. The name is officially an abbreviation of the phrase, "do communications over the mobile network", and is also from a compound word dokomo, meaning "everywhere" in Japanese...
's
Short Mail, both in
Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. E-mail messaging from phones, as popularized by NTT Docomo's
i-modeNTT DoCoMo's i-mode is a wireless internet service popular in Japan. Unlike Wireless Application Protocol or WAP, i-mode encompasses a wider variety of internet standards, including web access, e-mail and the packet-switched network that delivers the data...
and the RIM
BlackBerryBlackBerry is a line of wireless handheld devices that was introduced in 1999 as a two-way pager. In 2002, the more commonly known smartphone BlackBerry was released, which supports push e-mail, mobile telephone, text messaging, internet faxing, web browsing and other wireless information services....
, also typically use standard mail protocols such as
SMTPSimple Mail Transfer Protocol is an Internet standard for electronic mail transmission across Internet Protocol networks. SMTP was first defined in RFC 821 , and last updated by RFC 5321 which includes the extended SMTP additions, and is the protocol in widespread use today...
over
TCP/IPThe Internet Protocol Suite is the set of communications protocols used for the Internet and other similar networks. It is named from two of the most important protocols in it: the Transmission Control Protocol and the Internet Protocol , which were the first two networking protocols defined in...
.
SMS today
Commercially SMS is a massive industry in 2006 worth over 81 billion dollars globally. SMS has an average global price of 0.11 USD while costing providers almost nothing. Mobile networks charge each other so-called interconnect fees of at least £0.03 when connecting between different phone networks
GSM
The
Short Message Service - Point to Point (SMS-PP) is defined in GSM recommendation 03.40. GSM 03.41 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 CentreA Short Message Service Center is a network element in the mobile telephone network which delivers SMS messages.-Operation:When a user sends a text message to another user, the message gets stored in the SMSC which delivers it to the destination user when they are available...
(SMSC) which provides a
store-and-forwardStore 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 a networking context, verifies the integrity of...
mechanism. It attempts to send messages to their 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 that are sent from the mobile handset, operations are supported. Message delivery is
best effortBest effort delivery describes a network service in which the network does not provide any guarantees that data is delivered or that a user is given a guaranteed quality of service level or a certain priority. In a best effort network all users obtain best effort service, meaning that they obtain...
, so there are no guarantees that a message will actually be delivered to its recipient and delay or complete loss of a message is not uncommon, particularly when sending between networks. Users may request delivery reports to confirm that messages reach the intended recipients, either via the SMS settings of most modern phones, or by prefixing each message with *0# or *N#.
Message size
Transmission of short messages between the SMSC and the handset is done whenever using the
Mobile Application PartThe Mobile Application Part is an SS7 protocol which 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 mobile phone users...
(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
octetIn computing, an octet is a grouping of eight bits.Octet, with the only exception noted below, always refers to an entity having exactly eight bits. As such, it is often used where the term byte might be ambiguous. For that reason, computer networking standards almost exclusively use octet...
s (140 octets = 140 * 8 bits = 1120 bits). Short messages can be encoded using a variety of alphabets: the default GSM 7-
bitIn computing and telecommunications a bit is a basic unit of information storage and communication . It is the maximum amount of information that can be stored by a device or other physical system that can normally exist in only two distinct states...
alphabet (see
GSM 03.38The GSM 03.38 charset is defined in GSM recommendation 03.38. It is used in the Short Message Service of GSM based cell phones. Messages sent via this encoding can sent be sent as the default GSM 7-bit alphabet, the 8-bit data alphabet, and the 16-bit UTF-16 alphabet...
for details), the 8-bit data alphabet, and the 16-bit UTF-16 alphabet. Depending on which alphabet the subscriber has configured in the handset, this leads to the maximum individual Short Message sizes of 160 7-
bitIn computing and telecommunications a bit is a basic unit of information storage and communication . It is the maximum amount of information that can be stored by a device or other physical system that can normally exist in only two distinct states...
characters, 140 8-bit characters, or 70 16-bit characters (including spaces). Support of the GSM 7-bit alphabet is mandatory for GSM handsets and network elements, but characters in languages such as Arabic, Chinese, Korean, Japanese or Cyrillic alphabet languages (e.g. Russian, Serbian, Bulgarian, etc) must be encoded using the 16-bit UTF-16
character encodingA character encoding system consists of a code that pairs each character from a given repertoire with something else, such as a sequence of natural numbers, octets or electrical pulses, in order to facilitate the transmission of data through telecommunication networks or storage of text in...
(see
UnicodeUnicode is a computing industry standard allowing computers to consistently represent and manipulate text expressed in most of the world's writing systems...
).
RoutingRouting is the process of selecting paths in a network along which to send network traffic. Routing is performed for many kinds of networks, including the telephone network, electronic data networks , and transportation networks...
data and other
metadataMetadata is "data about data", of any sort in any media. Metadata is text, voice, or image that describes what the audience wants or needs to see or experience. The audience could be a person, group, or software program...
is additional to the payload size.
Larger content (
Concatenated SMSIn the cellular phone industry, mobile phones and their networks sometimes support concatenated short message service to overcome the limitation on the number of characters that can be sent in a single SMS text message transmission...
, 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 (UDH) containing segmentation information. Since UDH is inside the payload, the number of characters per segment is lower: 153 for 7-bit encoding, 133 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, 6 to 8 segment messages are the practical maximum, and long messages are often billed as equivalent to multiple SMS messages. See
Concatenated SMSIn the cellular phone industry, mobile phones and their networks sometimes support concatenated short message service to overcome the limitation on the number of characters that can be sent in a single SMS text message transmission...
for more information. Some providers have offered length-oriented pricing schemes for SMSs, however, the phenomenon is disappearing.
SMS Gateway providers
SMS gateway providers facilitate the SMS traffic between businesses and mobile subscribers, being mainly responsible for carrying mission-critical messages, 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
SS7SS-7 can stand for:* Signaling System #7, a set of telephone signaling protocols.* The R-16 missile, with NATO reporting name SS-7 Saddler.* China Railways SS7, an electric locomotive model in China.* Super Socket 7, a chip socket introduced by AMD...
providers.
The aggregator model is based on multiple agreements with mobile carriers to exchange 2-way SMS traffic into and out of the operator’s SMS platform (Short Message Service Centre – SMS-C), 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 in the operator’s SMS-C, but not the subscriber’s handset, the SMS-C takes care of further handling of the message through the SS7 network
Another type of SMS gateway 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 the SMS routing. This means SMS messages can be sent directly to and from recipients without having to go through the SMS-Centres of other mobile operators. Therefore, it’s possible to avoid delays and message losses, offering full delivery guarantees of messages and optimised routing. This model is particularly efficient when used in mission-critical messaging and SMS used in corporate communications.
Interconnectivity with other networks
Message Service Centres communicate with the
Public Land Mobile Network (PLMN)In telecommunication, a public land mobile network is a network that is established and operated by an administration or by a recognized operating agency for the specific purpose of providing land mobile telecommunications services to the public....
or
PSTNThe public switched telephone network is the network of the world's public circuit-switched telephone networks, in much the same way that the Internet is the network of the world's public IP-based packet-switched networks...
via Interworking and Gateway MSCs.
Subscriber-originated messages are transported from a handset to a Service Centre, and may be destined for mobile users, subscribers on a fixed network, or
Value-Added Service Providers (VASPs)A value-added service is popular as a telecommunications industry term for non-core services or, in short, all services beyond standard voice calls and fax transmissions but, it can be used in ANY service industry for the services providers provide for no cost to promote their main service business...
, also known as application-terminated. Subscriber-terminated messages are transported from the Service Centre to the destination handset, and may originate from mobile users, from fixed network subscribers, or from other sources such as VASPs.
It is also possible, on some carriers, for non-subscribers to send messages to a subscriber's phone using an E-Mail to SMS gateway. Additionally, many carriers, including
AT&TAT&T Inc. is the largest provider of local, long distance telephone services in the United States, and also serves digital subscriber line Internet access. AT&T is the second largest provider of wireless service in the United States, with over 77 million wireless customers, and more than 150...
,
T-MobileT-Mobile is a subsidiary of Deutsche Telekom and belongs to the FreeMove Business alliance.T-Mobile is a group of mobile phone corporate subsidiaries that operate GSM and UMTS networks in Europe and the United States. The T stands for Telekom. T-Mobile also has financial stakes in mobile operators...
,
SprintSprint Nextel Corporation is a telecommunications company based in Overland Park, Kansas.The company owns and operates the third-largest wireless telecommunications network in United States, with 49.3 million customers, behind Verizon Wireless and AT&T Mobility.Sprint is a global Internet carrier ...
, and
Verizon WirelessCellco Partnership, doing business as Verizon Wireless, owns and operates the largest wireless telecommunications network in the United States, based on a total of 87.7 million U.S. subscribers. Verizon Wireless has the largest revenue of all United States wireless companies reporting $58.6 billion...
, 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 e-mails to 5555555555@txt.att.net as text messages. Sending a message this way is free but subject to the normal length limit.
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 conversionSpeech synthesis is the artificial production of human speech. A computer system used for this purpose is called a speech synthesizer, and can be implemented in software or hardware...
.
Short messages can also be used to send binary content such as ringtones or logos, as well as
Over-the-air programmingOver-the-air programming may refer to either free-to-air, terrestrial television, or in the mobile content world, over-the-air service provisioning , over-the-air provisioning or over-the-air parameter administration , methods of distributing new software updates to cellphones or provisioning...
(OTA) or configuration data. Such uses are a vendor-specific extension of the GSM specification and there are multiple competing standards, although
NokiaNokia Corporation is a Finnish multinational communications corporation that is headquartered in Keilaniemi, Espoo, a city neighbouring Finland's capital Helsinki...
's
Smart MessagingSmart message is a protocol designed by Intel and Nokia, and by which various software upgrades -- including ringtones -- can be made "over the air", through your wireless connection....
is by far the most common. An alternative way for sending such binary content is
EMSEnhanced Messaging Service , is a cross-industry collaboration between Samsung, Ericsson, Motorola, Siemens and Alcatel, among others. It is an application-level extension to Short Message Service for cellular phones available on GSM, TDMA and CDMA networks.EMS is an intermediate technology,...
messaging which is standardised and not dependent on vendors.
Today, SMS is also used for M2M (
Machine to MachineM2M refers to data communications between machines. M2M is most commonly translated as Machine-to-Machine but has sometimes been translated as Man-to-Machine, Machine-to-Man, Machine-to-Mobile and Mobile-to-Machine. Among cellular telephone service providers, M2M means Mobile-to-Mobile, and is used...
) communication. For instance, there is an LED display machine controlled by SMS, and some
vehicle trackingA vehicle tracking system is an electronic device installed in a vehicle to enable the owner or a third party to track the vehicle's location. Most modern vehicle tracking systems use Global Positioning System modules for accurate location of the vehicle...
companies use SMS for their data
transportTransport or transportation is the movement of people and goods from one location to another. Transport is performed by modes, such as air, rail, road, water, cable, pipeline and space...
or
telemetryTelemetry is a technology that allows remote measurement and reporting of information. The word is derived from Greek roots tele = remote, and metron = measure. Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand.Although the term commonly...
needs. SMS usage for these purposes is slowly being superseded by
GPRSGeneral packet radio service is a packet oriented mobile data service available to users of the 2G cellular communication systems global system for mobile communications , as well as in the 3G systems...
services due to their lower overall costs. GPRS is also offered by some smaller telco players as a route of sending SMS text to help reduce the cost of SMS texting internationally.
AT commands
Many mobile and satellite
transceiverA transceiver is a device that has both a transmitter and a receiver which are combined and share common circuitry or a single housing. If no circuitry is common between transmit and receive functions, the device is a transmitter-receiver. The term originated in the early 1920s. Technically,...
units support the sending and receiving of SMS using an extended version of the
Hayes command setThe Hayes command set is a specific command-language originally developed for the Hayes Smartmodem 300 baud modem in 1977. The command set consists of a series of short text strings which combine together to produce complete commands for operations such as dialing, hanging up, and changing the...
, a specific
command-languageA command language is a domain-specific interpreted language; a common example of a command language are shell or batch programming languages. These languages can be used directly at the command line, but can also automate tasks that would normally be performed manually at the command line...
originally developed for the
HayesHayes Microcomputer Products was a U.S.-based manufacturer of modems. They are particularly well known for their Smartmodem, which introduced the ability to control the modem through commands sent in the data stream itself. The "smart modem" approach dramatically simplified operation, making modems...
Smartmodem 300
baudIn telecommunications and electronics, baud is synonymous to symbols per second or pulses per second. It is the unit of symbol rate, also known as baud rate or modulation rate; the number of distinct symbol changes made to the transmission medium per second in a digitally modulated signal or a...
modem in 1977.
The connection between the terminal equipment and the transceiver can be realized with a serial cable (i.e. USB), a
BluetoothBluetooth is an open wireless protocol for exchanging data over short distances from fixed and mobile devices, creating personal area networks . It was originally conceived as a wireless alternative to RS232 data cables...
link, an
infraredInfrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light , but shorter than that of terahertz radiation and microwaves...
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.
Short messages may be used to provide
Premium-rated short messages
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 Value-added service provider (VASP) providing the content submits the message to the mobile operator's SMSC(s) using a
TCP/IPThe Internet Protocol Suite is the set of communications protocols used for the Internet and other similar networks. It is named from two of the most important protocols in it: the Transmission Control Protocol and the Internet Protocol , which were the first two networking protocols defined in...
protocol such as the
short message peer-to-peer protocolThe Short Message Peer-to-Peer protocol is a telecommunications industry protocol for exchanging SMS messages between SMS peer entities such as short message service centers and/or External Short Messaging Entities. It is often used to allow third parties The Short Message Peer-to-Peer (SMPP)...
(SMPP) or the
External Machine Interface (EMI)External Machine Interface , an extension to Universal Computer Protocol , is a protocol primarily used to connect to short message service centres for mobile telephones...
. The SMSC delivers the text using the normal Mobile Terminated delivery procedure. The subscribers are charged extra for receiving this premium content, and the amount is typically divided between the
mobile network operatorA mobile network operator , also known as mobile phone operator , carrier service provider , wireless service provider, wireless carrier, mobile phone operator, or cellular company, is a telephone company that provides services for mobile phone subscribers.The process of becoming a...
and the VASP either through revenue share or a fixed transport fee.
Mobile originated short messages may also be used in a premium-rated manner for services such as
televotingTelevoting, 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:...
. In this case, the VASP providing the service obtains a
short codeShort codes, also known as short numbers, are special telephone numbers, significantly shorter than full telephone numbers, which can also be used to address SMS and MMS messages from mobile phones or fixed phones....
from the telephone network operator, and subscribers send texts to that number. The payouts to the carriers vary by carrier and the percentages paid are greatest on the lowest priced premium SMS services. Most information providers should expect to pay about 45% 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 Centre 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
IPThe Internet Protocol Suite is the set of communications protocols used for the Internet and other similar networks. It is named from two of the most important protocols in it: the Transmission Control Protocol and the Internet Protocol , which were the first two networking protocols defined in...
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. Limitations of short codes include the limitation to national borders (short codes have to be activated in each country where the campaign takes place), as well as being expensive to sign up together with mobile operators.
An alternative to inbound SMS is based on
long numbersLong number, also known as a virtual mobile number or long code, is a reception mechanism used by businesses to receive SMS messages and voice calls...
(international number format, e.g. +44 7624 805000),which can be used in place of short codes for SMS reception in several applications, such as TV voting, product promotions and campaigns.
Long numbersLong number, also known as a virtual mobile number or long code, is a reception mechanism used by businesses to receive SMS messages and voice calls...
are internationally available, as well as enabling businesses to have their own number, rather than short codes which are usually shared across a lot of brands. Additionally,
long numbersLong number, also known as a virtual mobile number or long code, is a reception mechanism used by businesses to receive SMS messages and voice calls...
are non-premium inbound numbers.
SMS in satellite phone networks
All commercial
satellite phoneA satellite telephone, satellite phone, or satphone is a type of mobile phone that connects to orbiting satellites instead of terrestrial cell sites. Depending on the architecture of a particular system, coverage may include the entire Earth, or only specific regions.The mobile equipment, also...
networks except
ACeSACeS is a regional satellite telecommunications company based in Jakarta, Indonesia. It offers GSM-like satellite telephony services to Asian market. The coverage area includes Indonesia, Malaysia, Thailand, Philippines, Sri Lanka, Vietnam, China and some part of India. The company operates Garuda...
and
OptusSatThis is a list of the satellites operated by Optus, an Australian telecommunications company.-A-Class:*Satellite Type: Hughes HS-376*Design Life: 7 Years for A1 & A2 - 10 Years for A3...
fully support SMS. While early Iridium handsets only support incoming SMS, later models can also send them. The price per message varies for the different networks and is usually between 25 and 50 cents per message. 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 a web-based or email-based SMS portals where one can send free SMS to phones on that particular network.
Vulnerabilities
The Global Service for Mobile communications (GSM), with the greatest worldwide number of users, succumbs to several security vulnerabilities. In the GSM, only the airway traffic between the
Mobile StationThe mobile station comprises all user equipment and software needed for communication with a Wireless telephone network.MS refers to the Mobile Phone.i.e. the handset held by the users in the mobile network. This is the terminology of 2G systems like GSM...
(MS) and the
Base Transceiver StationA base transceiver station or cell site is a piece of equipment that facilitates wireless communication between user equipment and a network. UEs are devices like mobile phones , WLL phones, computers with wireless internet connectivity, WiFi and WiMAX gadgets etc...
(BTS) is optionally encrypted with a weak and broken
stream cipherIn cryptography, a stream cipher is a symmetric key cipher where plaintext bits are combined with a pseudorandom cipher bit stream , typically by an exclusive-or operation. In a stream cipher the plaintext digits are encrypted one at a time, and the transformation of successive digits varies...
(
A5/1A5/1 is a stream cipher used to provide over-the-air communication privacy in the GSM cellular telephone standard. It was initially kept secret, but became public knowledge through leaks and reverse engineering. A number of serious weaknesses in the cipher have been identified.-History and...
or
A5/2A5/2 is a stream cipher used to provide voice privacy in the GSM cellular telephone protocol.The cipher is based around a combination of four linear feedback shift registers with irregular clocking and a non-linear combiner.In 1999, Ian Goldberg and David A...
). The
authenticationAuthentication is the act of establishing or confirming something as authentic, that is, that claims made by or about the subject are true...
is unilateral and also vulnerable. There are also many other security vulnerabilities and shortcomings. Such vulnerabilities are inherent to the
Short Message ServiceShort Message Service or Silent Messaging Service is a communication service standardized in the GSM mobile communication system, using standardized communications protocols allowing the interchange of short text messages between mobile telephone devices...
(SMS) as one of the superior and well-tried services with a global availability in the GSM networks. The 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, the SMS content passes through different networks, and perhaps the Internet, and is exposed to various vulnerabilities and attacks. Another concern arises when an adversary gets access to the phone and reads the previous unprotected messages.
In October 2005, researchers from
Pennsylvania State UniversityThe Pennsylvania State University is a state-related, land-grant, space grant public research university located in the University Park area and within State College and College Township in Pennsylvania, United States...
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 industry has identified a number of potential fraud attacks on mobile operators that are caused by abuse of SMS messaging services. The most serious of threats is SMS Spoofing. SMS Spoofing 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 100%-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 HLR before the message is submitted for delivery. This kind of intelligent routing function is beyond the capabilities of legacy messaging infrastructure.
See also
- Comparison of mobile phone standards
Global System for Mobile Communications and IS-95 are the two most prevalent mobile communication technologies...
- SMS language
SMS language or Textese is a term for the abbreviations and slang most commonly used due to the necessary brevity of mobile phone text messaging, though its use is common on the Internet, including e-mail and instant messaging...
- Telegram
- Text messaging
Text messaging, or texting, is a colloquial term referring to the exchange of brief written messages between mobile phones, over cellular networks. While the term most often refers to messages sent using the Short Message Service , it has been extended to include messages containing image, video,...
- Thumbing
Thumbing may refer to:*The act of typing on a small keyboard solely using the thumbs. It is primarily used with mobile phones for SMS text messaging, and also with devices such as PDAs with built-in keyboards....
Details
- Short Message Service Centre
A Short Message Service Center is a network element in the mobile telephone network which delivers SMS messages.-Operation:When a user sends a text message to another user, the message gets stored in the SMSC which delivers it to the destination user when they are available...
(SMSC)
- Short message service technical realisation (GSM)
The Short Message Service is realised by the use of the Mobile Application Part of the SS#7 protocol, with Short Message protocol elements being transported across the network as fields within the MAP messages. These MAP messages may be transported using 'traditional' TDM based signalling, or...
- SMS gateways
SMS gateway is a device or service offering SMS transit, transforming messages to mobile network traffic from other media, or vice versa, allowing transmission or receipt of SMS messages with or without the use of a mobile phone...
(sending texts to or from devices other than phones)
Related protocols
- 3rd Generation Partnership Project
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, to make a globally applicable third generation mobile phone system specification within the scope of the International Mobile Telecommunications-2000 project of the International...
(3GPP)
- Enhanced Messaging Service
Enhanced Messaging Service , is a cross-industry collaboration between Samsung, Ericsson, Motorola, Siemens and Alcatel, among others. It is an application-level extension to Short Message Service for cellular phones available on GSM, TDMA and CDMA networks.EMS is an intermediate technology,...
(EMS)
- Multimedia Messaging Service
Multimedia Messaging Service, or MMS, is a standard way to send messages that include multimedia content to and from mobile phones. It extends the core SMS capability which only allowed exchange of text messages up to 160 characters in length.The most popular use is to send photographs from...
(MMS) (a newer standard)
- Short message peer-to-peer protocol
The Short Message Peer-to-Peer protocol is a telecommunications industry protocol for exchanging SMS messages between SMS peer entities such as short message service centers and/or External Short Messaging Entities. It is often used to allow third parties The Short Message Peer-to-Peer (SMPP)...
(SMPP)
- External Machine Interface (EMI)
External Machine Interface , an extension to Universal Computer Protocol , is a protocol primarily used to connect to short message service centres for mobile telephones...
, an extension to the Universal Computer Protocol (UCP)
- WAP Push
- Signaling System 7
Related technology
- BlackBerry
BlackBerry is a line of wireless handheld devices that was introduced in 1999 as a two-way pager. In 2002, the more commonly known smartphone BlackBerry was released, which supports push e-mail, mobile telephone, text messaging, internet faxing, web browsing and other wireless information services....
- Instant messaging
Instant messaging is a form of real-time communication between two or more people based on typed text. The text is conveyed via devices connected over a network such as the Internet.-Overview:...
- Mobile dating
Mobile dating services, also known as cell dating, cellular dating,or cell phone dating, allow individuals to chat, meet, and possibly become romantically involved by means of text messaging, mobile chatting, and the mobile web....
- Short code
Short codes, also known as short numbers, are special telephone numbers, significantly shorter than full telephone numbers, which can also be used to address SMS and MMS messages from mobile phones or fixed phones....
- USSD
- Twitter
Twitter is a free social networking and micro-blogging service that enables its users to send and read messages known as tweets. Tweets are text-based posts of up to 140 characters displayed on the author's profile page and delivered to the author's subscribers who are known as followers...
- SPOT Satellite Messenger
The SPOT Satellite Messenger is a portable GPS and satellite communication device designed to be carried into remote locations where the user may require emergency assistance. It is manufactured by Axonn LLC and marketed by SPOT Inc., a subsidiary of Globalstar Inc.-How it works:To determine its...