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pdcp status report & discard timer
Posted on 17. Jun, 2013 by lohith
in LteWorld Forum
Hi All,
I am not getting clear idea , when we should use pdcp status report ? Whether it is used only during the re-establishment( i.e handover ) or in all the general cases .
And same with the discard timer. Whether timer should be started in all the cases in RLC AM mode . Please reply as soon as possible.
Thanks,
Lohith
3GPPi does not define all the
It seems that 3GPPi does not define all the cases but it should be used whenever upper layers request a PDCP re-establishment, for radio bearers that are mapped on RLC AM, as defined in section 5.3.1 of 36.323.
Same spec mentions to start the discardTimer associated with PDCP SDUi (if configured);
36.331 specifies the PDPi config as below
PDCP-Config ::= SEQUENCE {
discardTimer ENUMERATED {
ms50, ms100, ms150, ms300, ms500,
ms750, ms1500, infinity
} OPTIONAL, -- Cond Setup
:
:
:
:
Condition Setup => The field is mandatory present in case of radio bearer setup. Otherwise the field is optionally present, need ON.
pdcp discard timer
Hi ,
Thanks for the reply.I am not getting clear idea , When sdu is received from upper layer in pdcp , it is stored in transmission buffer and discard timer will be started and pdu has been passed to lower layers. Whether peer pdcp entity should send status report for each pdu? on reception of status report discard timer should be stopped ? and pdu should be removed from transmission buffer. or based on the delivery report of lower layer , discard timer should be stopped and pdu should be removed from transmission buffer?
I am not getting clear idea on this . please can you clarify this?
If no ack from local RLC
If no ack from local RLC within discard timer then packet can be dropped.
See link http://www.linkedin.com/groups/What-is-use-PDCP-discard-1180727.S.159971058