26 Nov
2013
26 Nov
'13
9:22 a.m.
On Mon, Nov 25, 2013 at 08:24:27AM +0100, Andreas Eversberg wrote:
generally there is always a re-send due to delay
between pcu and the
radio interface. if all rlc/mac data blocks of an llc frame have been
sent to the phone, a packet downlink ack control block is requested and
scheduled. the pcu repeats all unacknowledged data blocks in a loop
until it receives that requested control block. this way the pcu starts
re-sending data blocks that might got lost, before it actually knows if
and which blocks still need to be resend. (this procedure is described
in TS 04.60.)
Are you referring to 9.1.3.1 "Acknowledge state array V(B) for GPRS
TBF Mode"?
"
If there are no further RLC data blocks available for transmission
(i.e. the RLC data block with BSN= V(S) does not exist), the sending
side shall transmit the oldest RLC data block whose corresponding
element in V(B) has the value PENDING_ACK, then the next oldest block
whose corresponding element in V(B) has the value PENDING_ACK, etc.
"
With statistics in place it appears that for CS4 close to 50% of the
sent RLC blocks are re-sends. Is that what you expected when implementing
it?
holger
--
- Holger Freyther <hfreyther(a)sysmocom.de> http://www.sysmocom.de/
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