1. Service Capability Exposure Function User Guide
  2. SCEF Functional Summary
  3. Non-IP Data Delivery
  4. Reliable Data Service

Reliable Data Service

Reliable Data Service (RDS) is used by the UE and SCEF when using PDN Connection of PDN Type 'Non-IP'. This service provides a mechanism for the SCEF to determine if the data was delivered to the UE and for UE to determine if the data was delivered to SCEF.

When this service is enabled, a protocol is used between the end-points of the Non-IP PDN Connection. This protocol uses a packet header to identify if the packet requires an acknowledgement or is an acknowledgment and to allow detection and elimination of duplicate PDUs at the receiving endpoint. The port numbers in the header are used to identify the application on the originator and to identify the application on the receiver.

The UE indicates its capability of supporting RDS in the Protocol Configuration Options (PCO) to SCEF or P-GW. If SCEF or P-GW supports and accepts RDS, then it indicates to UE in the PCO that RDS is used if it is enabled in the APN configuration.

With the implementation of this feature, the SCEF supports the following:
  • SCEF supports Reliable data transfer for the Non-IP data delivery between UE and SCS/AS.
  • SCEF supports MT NIDD Submit Request with Reliable Data Service Configuration option.

    When non-IP data is sent to an External Group Identifier, RDS Configuration indicates that no reliable data service acknowledgment is requested.

  • SCEF suports RDS Configuration parameter in the NIDD Configuration Request.

    RDS Configuration is an optional parameter that is used to configure RDS.

  • SCEF suport s updating RDS Configuration parameter in the NIDD Configuration Request update.
  • SCEF includes Reliable Data Service Indication in the NIDD Configuration Response.

    RDS Indication indicates if the RDS is enabled in the APN configuration.

  • MT NIDD data delivery supports RDS Configuration parameter.
  • SCEF includes Reliable Data Service Acknowledgement Indication in the MT NIDD Submit Response.

    The RDS Acknowledgement Indication is used to indicate if an acknowledgment is received from UE for the MT NIDD. If RDS was requested, then MT NIDD Submit Response is sent to the SCS/AS after the acknowledgment is received from the UE. If acknowledgment is not received, then MT NIDD Submit Response is sent to SCS/AS with a cause value indicating that acknowledgment is not received.

    The UE sends RDS Acknowledgement Indication using the MO UL data.