Unstructured Supplementary Service Data

Unstructured Supplementary Service Data is a capability of all GSM phones. It is generally associated with real-time or instant messaging type phone services. There is no store-and-forward capability, such as is typical of other short-message protocols (in other words, an SMSC is not present in the processing path). Response times for interactive USSD-based services are generally quicker than those used for SMS.

USSD Phase 1, specified in GSM 02.90, only supports mobile initiated operation (pull operation). In the core network the message is delivered over MAP. USSD Phase 2, specified in GSM 03.90, supports network-initiated operation (pull and push operation).

As an analogy, USSD is similar to telnet, while SMS is similar to mail.

USSD is typically used as a 'trigger' to invoke independent calling services that don't require the overhead and additional usage costs of an SMSC, such as a callback service (e.g. cheaper phone charges while roaming), or interactive data service (e.g. stock quotes, sports results).

USSD is a standard for transmitting information over GSM signalling channels. It is mostly used as a method to query the available balance and other similar information in pre-paid GSM services. The function that is triggered when sending USSD is network-dependent and depends on the specific services the operator is offering.

Example USSD codes:
* *101#
* *109*72348937857623#

After entering a USSD code on your GSM handset, the reply from the GSM operator is displayed within a few seconds.

USSD is the base of some payment methods such as SharEpay in South Africa, Mobipay in Spain, and mPay in Poland.

Companies Working On USSD

*Ducont FZ LLC
* [http://www.inswitch.us INSwitch Solutions]
* [http://www.opencode.com Opencode Systems]
*Contakt Tech Solutions
*Spice communications Ltd.
*Group 2000
*Symsoft
*Bharti Telesoft Ltd.
* [http://www.wnipl.com WiFi Networks Pvt Ltd]
*eServGlobal
*Netxcell
*Cellebrum
*Eyeline Communications Inc.
*Cosmote
*Vodafone Romania
*InterAcct Solutions
*Syriatel
*ActiveXperts
*Orange
*Globitel
*uk2abroad
* [http://www.margento.com Margento]
*Ducont
*Comverse Technology
*TechUnified
*Myzus
* [http://www.pyrogroup.com/ Pyro Networks]
*Esmertec previously Cellicium
* [http://www.oksijen.com/ OKSIJEN]
*Sicap
*Telecom Italia Mobile
* [http://www.truteq.com Truteq Wireless]
*Flash Media Group
*Switchlab
*Syniverse
*Smartcall Technology Solutions
* [http://www.evistel.com/ Evistel]
*Pharos Avantgard
*Wind Mobile
*MCTEL
*Etisalat
*IMImobile
*ONMOBILE
*Six DEE Telecom Solution Pvt Ltd
*6d Technologies
*Noo Mobile Limited
* [http://www.m-ontheweb.com M Cash]
* [http://www.tkd.co.id Trans Komunikasi Data]
* [http://www.vidamo-group.com Vidamo | mobile marketing and enterprise solutions]
* [http://www.protei.com R&D Protei, Russia]
* [http://www.mobilearts.com Mobile Arts AB, Sweden]

Mobile payment using USSD

* [http://www.inswitch.us INSwitch Solutions]
*Group 2000
*Opencode Systems
*Contakt Tech Solutions
* [http://www.trivnet.com Trivnet]
*SEP Bulgaria
*mChek
*Sharepay
* [http://www.redknee.com Redknee]
*Mobipay
*EZY mPay
*mPay
*Payme
*Telepin Software
*du
*Etisalat
* [http://www.m-ontheweb.com M Cash]
*Swisscom Mobile
*Six DEE telecom Solutions Pvt. Ltd.
*Tigo Cash (Millicom)
*Mono (Magticom)

References

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External links

* [http://www.telecomspace.com/messaging-ussd.html USSD Overview at TelecomSpace.com]
* [http://www.3gpp.org/ftp/Specs/html-info/0390.htm GSM 03.90 (ETSI TS 100 549) Specification (USSD) at 3Gpp.org]
* [http://www.kenneyjacob.com/2007/06/12/ussd-applications-and-services/ USSD Applications and Services]
* [http://www.eyeline.mobi/blog/2008/06/19/is-ussd-hungry-for-ss7-the-answer-is-no/ Is USSD Hungry for SS7? No.]
* [http://www.eyeline.mobi/blog/2008/05/23/ussd-iphone/ An Example of USSD Use]