USSD Notification Process

The Notification Server sends Unstructured Supplementary Service Data (USSD) notifications to the engine for processing. The USSD service library converts the notification message text to USSD format and sends the notification to the Network Enabler for delivery.

USSD notifications are processed in the following way.
  1. A MATRIXX notification is triggered by the Charging Server and sent to the ActiveMQ gateway. The ActiveMQ gateway delivers it to the message broker (ActiveMQ).
  2. The Notification Server gets the message in compact MDC format from the ActiveMQ notification request queue.
  3. Because the delivery channel for the notification is USSD, the Notification Server sends the message to the ActiveMQ USSD request queue in a MtxUssdCallOutRequestMsg MDC. The MtxUssdCallOutRequestMsg MDC includes USSD properties such as the USSD coding scheme to use, the destination SCCP address, the MAP protocol version to use, and others.
  4. The ActiveMQ gateway receives the MtxUssdCallOutRequestMsg MDC from the ActiveMQ USSD request queue.
  5. Based on the configured USSD coding scheme, the USSD service library compresses the notification text and converts it to USSD format. For information about USSD coding schemes, see the 3G TS 23.038 protocol specification.
    1. The USSD service library creates a TCAP session from the MtxUssdCallOutRequest message, and returns the MtxUssdCallOutRequest message containing the TCAP OID to the ActiveMQ USSD response queue.

      A message is written to the system log file recording the Notify ID and TCAP OID for the initial USSD request message sent from the Notification Server.

    2. The USSD service library sends a TCAP Begin(MAP USSD Notify) message containing the USSD message to the Network Enabler. Based on the SCCP address in the USSD message, Network Enabler sends the TCAP message to the network and forwards the returned result to the Charging Server.

      The result is logged in the system log file. The log message includes the Notify ID and the TCAP OID. This information can be used to correlate the returned results with the original USSD request message, for example, in case of errors.

  6. The Notification Server receives the MtxUssdCallOutRequest message including the TCAP OID from the ActiveMQ USSD response queue.
  7. The Notification Server creates a message MDC acknowledgement which includes the TCAP OID and the USSD notification message being delivered and sends it to the ActiveMQ notification response queue.
  8. The ActiveMQ gateway gets the message MDC and deletes the notification.
Figure 1 shows how USSD notification messages are handled by MATRIXX Engine:
Figure 1. USSD Notification Process