Unstructured Supplementary Service Data (USSD), sometimes referred to as "quick codes" or "feature codes", is a communications protocol used by GSMcellular telephones to communicate with the mobile network operator's computers. USSD can be used for WAP browsing, prepaid callback service, mobile-money services, location-based content services, menu-based information services, and as part of configuring the phone on the network.[1]
USSD messages are up to 182 alphanumeric characters long. Unlike short message service (SMS) messages, USSD messages create a real-time connection during a USSD session. The connection remains open, allowing a two-way exchange of a sequence of data. This makes USSD more responsive than services that use SMS.[1]
When a user sends a message to the phone company network, it is received by a computer dedicated to USSD. The computer's response is sent back to the phone, generally in a basic format that can easily be seen on the phone display. Messages sent over USSD are not defined by any standardization body, so each network operator can implement whatever is most suitable for its customers.
USSD can be used to provide independent calling services such as a callback service (to reduce phone charges while roaming), enhance mobile marketing capabilities or interactive data services.
USSD is commonly used by prepaid GSM cellular phones to query the available balance. The vendor's "check balance" application hides the details of the USSD protocol from the user. On some pay as you go networks, such as Tesco Mobile, once a user performs an action that costs money, the user sees a USSD message with their new balance. USSD can also be used to refill the balance on the user's SIM card and to deliver one-time passwords or PIN codes.
Some operators use USSD to provide access to real-time updates from social-networking websites like Facebook and Twitter.[2]Wikipedia uses USSD to send articles to some feature phones.[3]
USSD is sometimes used in conjunction with SMS. The user sends a request to the network via USSD, and the network replies with an acknowledgement of receipt:
"Thank you, your message is being processed. A message will be sent to your phone."
Subsequently, one or more mobile terminated SMS messages communicate the status and/or results of the initial request.[4] In such cases, SMS is used to "push" a reply or updates to the handset when the network is ready to send them.[5] In contrast, USSD is used for command-and-control only.
Technical details
Most GSM phones have USSD capability.[6] USSD is generally associated with real-time or instant messaging services. There is no store-and-forward capability, as is typical of other short-message protocols like SMS. In other words, an SMSC is not present in the processing path.
USSD Phase 1, as specified in GSM 02.90, only supports mobile-initiated ("pull") operations.[7] In the core network, the message is delivered over MAP, USSD Phase 2, as specified in GSM 03.90.[8] After entering a USSD code on a GSM handset, the reply from the GSM operator is displayed within a few seconds.
Format
A typical USSD message starts with an asterisk (*) followed by digits that comprise commands or data. Groups of digits may be separated by additional asterisks. The message is terminated with a hash symbol (#).[1]
USSD mode
Mobile-initiated
USSD/ PULL or USSD/ P2A
when the user dials a code, e.g. *139# from a GSM mobile handset
Network-initiated
USSD/ PUSH or USSD/A2P
when the user receives a push message from the network; primarily used for promotional services
The codes below are not USSD codes, but rather MMI Supplementary Service codes; they are standardized so they are the same on every GSM phone. They are interpreted by the handset first before a corresponding command (not the code itself) is sent to the network. These codes might not always work when using an AT interface; there are standard AT commands defined for each of these actions instead.[9][10]
BS is the type of bearer service, some valid values are:
11 for voice
13 for fax
16 for SMS (only valid for barring)
25 for data
<leave blank> for all.
T is number of seconds for the No Reply Condition Timer, default is 20 seconds if not specified.
GSM USSD codes and their functions with various network operators
Code
Function
Note
Switch on
Switch off
Display status
002
all diversions
unconditional, busy, unreachable, does not answer
* * 002 * number * BS * T #
# # 002 * * BS #
* # 002 * * BS #
004
all conditional redirections
busy, unreachable, does not answer
* * 004 * number * BS * T #
# # 004 * * BS #
* # 004 * * BS #
03
Change Network password
password is network dependent, default on some networks is 0000. See call barring functions *33
* * 03 * 330 * old password * new password * new password #
What’s the difference between USSD, MMI and SS codes?
Android USSD codes list (MMI code list)
January 06, 2023
unstructured, supplementary, service, data, ussd, redirects, here, organization, united, states, society, dams, ussd, sometimes, referred, quick, codes, feature, codes, communications, protocol, used, cellular, telephones, communicate, with, mobile, network, o. USSD redirects here For the organization see United States Society on Dams Unstructured Supplementary Service Data USSD sometimes referred to as quick codes or feature codes is a communications protocol used by GSM cellular telephones to communicate with the mobile network operator s computers USSD can be used for WAP browsing prepaid callback service mobile money services location based content services menu based information services and as part of configuring the phone on the network 1 USSD on a Sony Ericsson mobile phone 2005 USSD messages are up to 182 alphanumeric characters long Unlike short message service SMS messages USSD messages create a real time connection during a USSD session The connection remains open allowing a two way exchange of a sequence of data This makes USSD more responsive than services that use SMS 1 Contents 1 Uses 2 Technical details 2 1 Format 2 2 USSD mode 3 Code table 4 See also 5 References 6 External linksUses EditWhen a user sends a message to the phone company network it is received by a computer dedicated to USSD The computer s response is sent back to the phone generally in a basic format that can easily be seen on the phone display Messages sent over USSD are not defined by any standardization body so each network operator can implement whatever is most suitable for its customers USSD can be used to provide independent calling services such as a callback service to reduce phone charges while roaming enhance mobile marketing capabilities or interactive data services USSD is commonly used by prepaid GSM cellular phones to query the available balance The vendor s check balance application hides the details of the USSD protocol from the user On some pay as you go networks such as Tesco Mobile once a user performs an action that costs money the user sees a USSD message with their new balance USSD can also be used to refill the balance on the user s SIM card and to deliver one time passwords or PIN codes Some operators use USSD to provide access to real time updates from social networking websites like Facebook and Twitter 2 Wikipedia uses USSD to send articles to some feature phones 3 USSD is sometimes used in conjunction with SMS The user sends a request to the network via USSD and the network replies with an acknowledgement of receipt Thank you your message is being processed A message will be sent to your phone Subsequently one or more mobile terminated SMS messages communicate the status and or results of the initial request 4 In such cases SMS is used to push a reply or updates to the handset when the network is ready to send them 5 In contrast USSD is used for command and control only Technical details EditMost GSM phones have USSD capability 6 USSD is generally associated with real time or instant messaging services There is no store and forward capability as is typical of other short message protocols like SMS In other words an SMSC is not present in the processing path USSD Phase 1 as specified in GSM 02 90 only supports mobile initiated pull operations 7 In the core network the message is delivered over MAP USSD Phase 2 as specified in GSM 03 90 8 After entering a USSD code on a GSM handset the reply from the GSM operator is displayed within a few seconds Format Edit A typical USSD message starts with an asterisk followed by digits that comprise commands or data Groups of digits may be separated by additional asterisks The message is terminated with a hash symbol 1 USSD mode Edit Mobile initiated USSD PULL or USSD P2A when the user dials a code e g 139 from a GSM mobile handsetNetwork initiated USSD PUSH or USSD A2P when the user receives a push message from the network primarily used for promotional servicesExample USSD codes 101 139 1 1234567890 Code table EditThis section may contain material unrelated or insufficiently related to the topic of the article Please help improve this section or discuss this issue on the talk page September 2016 Learn how and when to remove this template message The codes below are not USSD codes but rather MMI Supplementary Service codes they are standardized so they are the same on every GSM phone They are interpreted by the handset first before a corresponding command not the code itself is sent to the network These codes might not always work when using an AT interface there are standard AT commands defined for each of these actions instead 9 10 BS is the type of bearer service some valid values are 11 for voice 13 for fax 16 for SMS only valid for barring 25 for data lt leave blank gt for all T is number of seconds for the No Reply Condition Timer default is 20 seconds if not specified GSM USSD codes and their functions with various network operators Code Function Note Switch on Switch off Display status002 all diversions unconditional busy unreachable does not answer 002 number BS T 002 BS 002 BS 004 all conditional redirections busy unreachable does not answer 004 number BS T 004 BS 004 BS 03 Change Network password password is network dependent default on some networks is 0000 See call barring functions 33 03 330 old password new password new password 04 Change PIN 04 old PIN new PIN new PIN 042 Change PIN2 Only with Phase 2 SIM 042 old PIN2 new PIN2 new PIN2 05 Change PIN by PUK 05 PUK new PIN new PIN 052 Change PIN2 via PUK Only with Phase 2 SIM 052 PUK new PIN2 new PIN2 06 read device number IMEI 06 21 unconditional divert all incoming calls will be diverted 21 number BS 21 BS 21 BS 30 get the caller s number displayed CLIP as a callee get the CLIP displayed 30 30 30 31 suppressing the transmission of caller s phone number CLIR for all subsequent calls 31 31 31 31 temporary change of the transmission of CLIR valid just for the next call no final 31 number 31 number330 total incoming and outgoing service barring password is network dependent default on some networks is 0000 330 password BS 330 password BS 330 BS 33 outgoing call barring password is network dependent default on some networks is 0000 33 password BS 33 password BS 33 BS 331 outgoing international call barring password is network dependent default on some networks is 0000 331 password BS 331 password BS 331 BS 332 outgoing international call barring excluding to home password is network dependent default on some networks is 0000 332 password BS 332 password BS 332 BS 333 total outgoing service barring password is network dependent default on some networks is 0000 333 password BS 333 password BS 333 BS 35 incoming call barring password is network dependent default on some networks is 0000 Incompatible with call diversion 35 password BS 35 password BS 35 BS 351 incoming call barring when international roaming password is network dependent default on some networks is 0000 351 password BS 351 password BS 351 BS 353 total incoming service barring password is network dependent default on some networks is 0000 353 password BS 353 password BS 353 BS 37 Call back on busy CCBS valid on some mobile networks only 37 37 37 43 incoming call notification when busy aka call waiting 43 BS 43 BS 43 BS 61 call divert when not answered 61 number BS T 61 BS 61 BS 62 call divert when off or not reachable 62 number BS 62 BS 62 BS 67 call divert when busy or pressing reject 67 number BS 67 BS 67 BS Code Function Note Switch on Switch off Display statusSee also EditUSSD Gateway Ultra Mobile Broadband Supplementary service codes Call forwarding Mobile cell phones SIM Application ToolkitReferences Edit a b c Unstructured Supplementary Services Data USSD Telecom Space Retrieved August 23 2010 TATA Docomo introduces Facebook Twitter access via USSD 16 July 2011 Retrieved 12 Nov 2019 Wadhwa Kul 22 February 2013 Getting Wikipedia to the people who need it most Wikimedia blog Wikimedia Foundation Retrieved 10 May 2013 Monitor usage on your phone AT amp T Residential Wireless Support Archived from the original on 11 May 2012 Retrieved 14 May 2012 Manage your account AT amp T Residential Wireless Support AT amp T Retrieved 11 May 2013 Windows Phone 7 doesn t support USSD Microsoft Answers Microsoft 8 February 2012 Retrieved 11 May 2013 GSM 02 90 ETSI TS 100 625 V7 0 0 Specification USSD Stage 1 3gpp org 3rd Generation Partnership Project Retrieved 11 May 2013 GSM 03 90 ETSI TS 100 549 V7 0 0 Specification USSD Stage 2 3gpp org 3rd Generation Partnership Project Retrieved 11 May 2013 http www etsi org deliver etsi ts 122000 122099 122030 10 00 00 60 ts 122030v100000p pdf bare URL PDF What s the difference between USSD MMI and SS codes External links EditGSM 04 90 ETSI EN 300 957 V7 0 1 Specification USSD Stage 3 3GPP 3GPP TS 22 030 What s the difference between USSD MMI and SS codes Android USSD codes list MMI code list Retrieved from https en wikipedia org w index php title Unstructured Supplementary Service Data amp oldid 1108999597, wikipedia, wiki, book, books, library,
