Yeah, there's some ambiguity here. For example, the wait event descriptions for 11.2 are:
"LNS wait on SENDREQ:
Total time spent waiting for redo data to be written to all ASYNC and SYNC redo transport destinations"
which suggests LNS will be handling sync.
However, in 12, the events are renamed, and this is one of the new ones:
"SYNC Remote Write:
The time spent by LGWR doing SYNC RFSWRITE operations"
which of course suggests the opposite :-)
And just for good measure, one of the features of moving to 11.2 for DataGuard was that 'sync' performance was improved, because:
"transmitting redo to the remote standby is done in parallel with LGWR writing redo to the local online log file of the primary database"
You'll see see a whole lot of new background process from 11.2 onwards, solely for redo transport,
SQL> select name, description from v$bgprocess
2 where lower(description) like '%redo%' order by name;
NAME DESCRIPTION
----- -----------------------------------------------------
LGWR Redo etc.
NSS1 Redo transport NSS1
NSS2 Redo transport NSS2
NSS3 Redo transport NSS3
NSS4 Redo transport NSS4
NSS5 Redo transport NSS5
NSS6 Redo transport NSS6
...
...
so the world changes rapidly :-)
Some good reading here
http://www.oracle.com/technetwork/database/features/availability/maa-096107.html Hope this helps.