Unstructured Supplementary Service Data

"USSD" redirects here. For the organization, see United States Society on Dams.
USSD on a Sony Ericsson mobile phone (2005)

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] The service does not require a messaging app, and does not incur charges.[2]

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 faster than services that use SMS.[1]

While GSM is being phased out in the 2020s with 2G and 3G technologies, USSD services can be supported over LTE, 5G, and IMS.

  1. ^ a b "Unstructured Supplementary Services Data (USSD)". Telecom Space. Archived from the original on March 3, 2021. Retrieved August 23, 2010.
  2. ^ Scard, Jen (12 July 2022). "What is USSD?". Wireless Logic.