Not sure if the problem is in the MAC layer or in the RLC v2 layer.
Maybe the buffer status reporting in RLC v2 is not good. Let's remove
two AssertFatal in the MAC for the time being.
Limitation: this fix only works if there is only one eNB,
because we force module_id = 0 in the function deliver_sdu where
(as the code is today) we have no way to know which module_id is
concerned. More generally, the rlc v2 does not work with more than
1 eNB.
The old method was wrong.
The new method is better, but not accurate, especially when the
TX buffer contains SDU of size > 2047 bytes.
Plus it's probably too slow.
To be refined at some point.
This commit introduces an alternative RLC implementation
based on 36.322 version 8. AM and UM done, TM not done.
See openair2/LAYER2/rlc_v2/TODO for missing parts.
Instead of looping over UEs and all DL config Req/HI DCI0, loop first
over all DL config Req/HI DCI0, and for each, match UE. Lowers CPU
traffic for high traffic situations.
This refactors the preprocessor. The new preprocessor implements the
same scheduling strategy (Modified Round-Robin: give resources according
to round-robin, then group) but should be fairer by changing every time
the RR start UE (i.e., 1st TTI UE 0 starts, 2nd TTI UE 1, etc) when the
UE number is not a divisor/multiple of the RBG size (and the last RBG is
often smaller). This also removes all unneeded code of the preprocessor
such as allocate(), positioning(), etc.
* do not check rlc_ind()
* Simplify retransmission part and remove nb_rb_available var
* Simplify new transmission code
* Simplify fill_DLSCH_dci(), avoid unnecessary copies
* fix: first check No. RBs, then check CCE alloc
Previously, the various rlc_*_ind() functions had a parameter to enable
the MAC to specify the max TB size that a subsequent call to the
corresponding rlc_*_req() (!) function would return. This patch removes
this parameter from the rlc_*_ind() functions and makes the parameter
working that is already in the rlc_*_req() functions.
store_dlsch_buffer() puts the RLC buffer status results in the
UE_TEMPLATE, which is per-CC. Since the DLSCH scheduler works per-CC,
too, we pass the right CC. However, this is not strictly necessary, as
we could do this once before every CC, and it might be updated.
UE_list_t is now used as a separate list. It can be e.g. used in the
scheduler to mark groups of users. The original UE_list_t is renamed to
UE_info_t to reflect that it is a container for information about UEs.
Cedric Roux