Definition of USSD

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Definition:

USSD or Unstructured Supplementary Service Data is a protocol used by GSM based mobile phones to communicate with the network operator’s computer.

USSD is widely used for a variety of purposes, such as prepaid callback service, location-based content service, WAP browsing and so on. Additionally, it is also used as a part of configuring the user’s handheld on the network.

Unlike the SMS, the USSD establishes a connection in real-time between the parties involved, thereby enabling a two-way communication of information as long as the connection remains open.