6.5.5 Handling of Error Event procedure

25.4153GPPRelease 17TSUTRAN Iu interface user plane protocols

6.5.5.1 Successful operation

The purpose of the Handling of Error Event procedure is to handle the error reporting. Over the Iu UP protocol the error reports are made with ERROR EVENT control frames. The Handling of Error Event procedure in the Iu UP can be triggered by:

– An error detected by the Iu UP functions (by receiving an erroneous frame or by receiving a frame with unknown or unexpected data). In this case an Iu UP- Status Indication may be used to inform the upper layers;

– A request by the upper layers.

When an Error event is reported by an ERROR EVENT control frame the following information shall be included:

– A cause value;

– Error distance (=0 if Iu UP function detected, =1 if requested by upper layers).

Upon reception of an ERROR EVENT control frame the Iu UP functions should take appropriate local actions based on the cause value. This may include reporting the error to the upper layers with an Iu UP status indication.

Figure 15b: Successful Error event

6.5.5.2 Unsuccessful operation

If the ERROR EVENT control frame is incorrectly formatted and cannot be correctly treated by the receiving Iu UP protocol layer appropriate local actions are taken (e.g. upper layers are informed). An error in an ERROR EVENT control frame should not generate the sending of a new ERROR EVENT control frame.

Figure 16c: Unsuccessful Transfer of ERROR EVENT control frame: 1) Frame loss 2) Corrupted Frame