Sx Interface

Sx Session Level Reporting Procedure

Detection of first Downlink Data for Idle-Mode UE (by SAEGW-U):

When SAEGW-U receives the downlink packet but no S1-bearer for transmission and the buffering is performed by SAEGW-U, it reports the detection of first downlink data to SAEGW-C, for the purpose of paging the UE.

PFCP Session Report Request

The PFCP Session Report Request is sent over the Sxab interface by the User Plane function to report information related to a PFCP session to the Control Plane function.

Information elements

P

Condition / Comment

Appl.

IE Type

Sxa

Sxb

Sxc

N4

Report Type

M

This IE shall indicate the type of the report.

X

X

X

X

Report Type

Downlink Data Report

C

This IE shall be present if the Report Type indicates a Downlink Data Report.

X

-

-

X

Downlink Data Report

Downlink Data Report IE within PFCP Session Report Request

The Downlink Data Report grouped IE is encoded as shown in the following table.

Octet 1 and 2

Downlink Data Report IE Type = 83 (decimal)

Octets 3 and 4

Length = n

Information elements

P

Condition / Comment

Appl.

IE Type

Sxa

Sxb

Sxc

N4

PDR ID

M

This IE shall identify the PDR for which downlink data packets have been received at the UP function.

More than one IE with this type may be included to represent multiple PDRs having received downlink data packets.

X

-

-

X

PDR ID

Notification to User Plane Function for DDN Failure

The Control Plane function notifies User Plane function for any failure so that buffered packets can be dropped and DDN related flags can be reset through DROBU flag in PFCP Sx Modification message.

PFCPSMReq-Flags

C

DROBU (Drop Buffered Packets): The CP function shall set this flag if the UP function is requested to drop the packets currently buffered for this PFCP session (see NOTE 1).