If anybody can highlight which Layer 2 messages should appear in 5G logfiles in EN-DC and why?
As we know EN-DC all control is going through MCG, rest PDCP harq and other messages should be seen in Layer 2 when analysing a 5G logfile?
There is no PDCP Harq. Harq is implemented at MAC layer.
I think beam changes should be seen in Layer 2.
Also al MAC control elements.
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I believe in 5G PDCP can do retransmissions, during HO.
You mean when 5G base station is connected to 5G core network?
I can not recall if it is the same with NSA.
BUT FOR 5G SA, yes.
But restransmission is done by RLC layer, and AM do this job.
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Yes RLC does retrasmissions.
Harq retransmissions are also possible at MAC layer, there is no harq at PDCP layer.
For the initial question, PDCP, RLC and MAC.
Layer 3 RRC reconfiguration in Master LTE node gives the details of PDCP entity in 5G NR as shown below:
Here the PDCP bearer is split at MCG(LTE node) and then more than one RLC layer ie LTE RLC and 5G RLC is used for data transmission,
[5G-NR RRC_F40 Data] :
value RadioBearerConfig ::=
drb-ToReleaseList
4
[5G-NR RRC_F40 Data] :
value RadioBearerConfig ::=
drb-ToAddModList
cnAssociation eps-BearerIdentity : 5,
drb-Identity 6,
pdcp-Config
drb
discardTimer infinity,
pdcp-SN-SizeUL len18bits,
pdcp-SN-SizeDL len18bits,
headerCompression notUsed : NULL
,
moreThanOneRLC
primaryPath
cellGroup 0 ## means uses more than 1 RLC with MCG SPLIT
,
ul-DataSplitThreshold infinity,
pdcp-Duplication FALSE
,
t-Reordering ms200
,
securityConfig
securityAlgorithmConfig
cipheringAlgorithm nea2
,
keyToUse secondary ## uses 5G NR also in lower layer
[5G-NR RRC_F40 Data] :
please, why has SCG split been more preferred by industry vs. MCG split?