What is PDCP configuration for SRB1 and 2 ?

Question

For SRB's mentioned default parameter values :

RLC configuration CHOICE
ul-RLC-Config
>t-PollRetransmit
>pollPDU
>pollByte
>maxRetxThreshold
dl-RLC-Config
>t-Reordering
>t-StatusProhibit
Logical channel configuration
priority
prioritisedBitRate
bucketSizeDuration
logicalChannelGroup

So is their any default parameters value for DRB for RLC AM mode in LTE for UL & DL?

Answer 1

eNodeB will not provide any PDCP configuration for SRB 1 and 2.
In general as per the RRC specification, while establishing DRB's eNodeB will provide the below configurations:-
rlc-mode, ROHC profile, integrity protection flag, PDU discard timer and sequence number bit length etc..

But for SRB's by default PDCP has the below configuration as per the PDCP specification:-
rlc-mode(AM), Integrity Protection enabled, and fixed 5 bit sequence number bit length.

Comments

Does this default PDCP configuration included PDCP-discard timer ?

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packet time based discard mechanism is introduced in PDCP Buffer Management Scheme.Packets are time stamped upon their arrival to the PDCP buffer. Waiting time of packets in the PDCP buffer is monitored at the MAC scheduling data sending trigger events. All the packets which exceed the maximum limit of waiting time are discarded and packets which are in sequence next are sent to the RLC layer for the transmission over the Uu interface. With the help of this scheme a precise upper bound on PDCP buffering delay can be achieved. Discard timer mechanism is applied independently on PDCP buffer on each bearer.
So i think the PDCP-discard timer will applicable for both SRB & DRB.