some RF boards might have issues with the sharp filters that are needed
for the reduced sample rate operation that we use by default.
This switch allows to use the default LTE sampling rates and
configure this at run-time, not compile time.
this potentially fixes the issue we see during HO and RLF
under high DL load.
The issue happens because buffered DL PDUs are delivered to
RLC after reestablishing RLC that confuse the receiving
RLC entity bc the sequence numbers are very high, as opposed
to begin with zero again after reestablishment.
* mac_test: add extended TBSR unit test
unit test to MAC UL packing after sending a TBSR
this fixes the MAC issues described in issue #2002
* mux: fix updating of LCG buffer state after packing PDU
we've previously lowered the buffer state of the LCG according
to the bytes that have been scheduled, but not according to
those that have been actually included in the PDU.
* proc_bsr: fix LCG buffer state updating for TBSR
when sending a TBSR do not update the internal buffer
state of the BSR proc.
This caused issues because the buffer state for all LCG that
are not included in the TBSR are set to zero, although at least
one LCG does have data to transmit.
* rlc_am: include LCID when logging retx of SN
the current implementation was somehow broken after a
NAS refactor. It was undetected because we didn't really
use it.
this fixes the simulation by using a single timer to simulate
airplane mode transitions.
the timer is rearmed in the timer_expire() function
if the correspondig event is set.
Has been tested to work well with, e.g.:
--sim.airplane_t_on_ms 5000 --sim.airplane_t_off_ms 10000
fix for #1934
This fixes a race condition between Stack thread and DL
PDU processing that lead to updates of the RLC buffer that
are undetected by the BSR routine.
What happens is that in a UL SCH PDU all outstanding data is transmitted
and and a LBSR with all zero buffers is sent.
14:39:47.327301 [MAC ] [D] [ 3793] BSR: LCID=3 old_buffer=59
14:39:47.330600 [MAC ] [I] [ 3793] UL LCID=3 len=58 LBSR: b=0 0 0 0
Note that "old_buffer" isn't set to zero here.
At the same time (same TTI), the MAC PDU processing thread handles DL-SCH PDUs
that may generate new UL PDUs:
14:39:47.330749 [RLC ] [I] DRB1 Tx SDU (54 B, tx_sdu_queue_len=1)
14:39:47.330762 [RLC ] [I] DRB1 Tx SDU (54 B, tx_sdu_queue_len=2)
14:39:47.330775 [RLC ] [I] DRB1 Tx SDU (54 B, tx_sdu_queue_len=3)
..
Those PDUs are "new data" since the previous buffer state was zero.
Here is the race now between the threads, at the end of the bsr::step() function
old_buffer of each LCG is updated with the previous new_buffer, so
the buffer state of LCG=2 is now 59.
Now MAC starts the next TTI:
14:39:47.331910 [MAC ] [D] [ 3794] Running MAC tti=3794
14:39:47.331928 [MAC ] [D] [ 3794] Update Bj: lcid=0, Bj=0
14:39:47.331934 [MAC ] [D] [ 3794] Update Bj: lcid=1, Bj=0
14:39:47.331938 [MAC ] [D] [ 3794] Update Bj: lcid=2, Bj=0
14:39:47.331941 [MAC ] [D] [ 3794] Update Bj: lcid=3, Bj=-1752
14:39:47.331951 [MAC ] [D] [ 3794] BSR: LCID=0 update new buffer=0
14:39:47.331960 [MAC ] [D] [ 3794] BSR: LCID=1 update new buffer=0
14:39:47.331964 [MAC ] [D] [ 3794] BSR: LCID=2 update new buffer=0
14:39:47.331971 [MAC ] [D] [ 3794] BSR: LCID=3 update new buffer=335
14:39:47.331976 [MAC ] [D] [ 3794] BSR: check_new_data() -> get_buffer_state_lcg(0)=0
14:39:47.331980 [MAC ] [D] [ 3794] BSR: check_new_data() -> get_buffer_state_lcg(1)=0
14:39:47.331984 [MAC ] [D] [ 3794] BSR: check_new_data() -> get_buffer_state_lcg(2)=59
14:39:47.331988 [MAC ] [D] [ 3794] BSR: check_new_data() -> get_buffer_state_lcg(3)=0
14:39:47.331993 [MAC ] [D] [ 3794] BSR: LCID=0 old_buffer=0
14:39:47.332000 [MAC ] [D] [ 3794] BSR: LCID=1 old_buffer=0
14:39:47.332003 [MAC ] [D] [ 3794] BSR: LCID=2 old_buffer=0
14:39:47.332007 [MAC ] [D] [ 3794] BSR: LCID=3 old_buffer=335
And since the buffer state of LCG=2 isn't zero, the new data for LCID=3 of that LCG is considered.
So effectivly, the BSR missed the "empty" buffer state for a fraction of time and doesn't
consider the outgoing data generated in the same TTI as new. It therefore
doesn't transmit a BSR.
in which a BSR wasn't
this was a very noisy log that was printed in pretty much
every TTI because the BSR procedure starts a SR whenever
it needs to send a regular BSR. The SR is canceled when a UL
grant arrives but the log line stays there.
Since we are printing a log when we actually signal a SR
to the PHY, this line is not needed.
this fixes the trigger logic for periodic BSRs. Previously we
would always trigger the "new data for highest priority LCID"
whenever new data becomes available for a LCID for which
a BSR has already been sent.
However, a BSR should only be sent if the priority is in fact higher
(lower int number).
the BSR routine had a bug in which it would generate a BSR even
before the reTx timer expires if new data becomes availble
for a LCID that already had data and a BSR was already sent.
The RA test here relies on a BSR in the generated MAC PDU to pass.
However, since after fixing the BSR bug the PDU the MUX unit
no longer generates a BSR, we need generate data for a LCID
which has higher priority than the one for which a BSR has
already been sent.
Xavier Arteaga
Andre Puschmann
Francisco
Pedro Alvarez
David Rupprecht
Ismael Gomez