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USSD or Unstructured Supplementary Service Data is a communication protocol accessible on each GSM-enabled mobile device and used by GSM cellular telephones to interface with the service provider’s computers.
USSD messages can contain up to 182 alphanumeric characters and the time it takes from a request to a response is 2 seconds while it takes 6 seconds for an SMS to reach a mobile phone.
USSD is a session-based text communication lacking a store-and-forward mechanism that is common for interactional transmission, such as banking or education.
USSD is session-based text communication protocol available on every GSM-enabled mobile tool.