Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

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.

Not very clean, but will do the job 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 UE code to compute BSR is too complex, has to be reworked/simplified.
This commit just removes the assert, does not solve anything.

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.

simply ignore the error

maybe not the best solution

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.

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

The UE code to compute BSR is too complex, has to be reworked/simplified.
This commit just removes the assert, does not solve anything.

hotfix: better CQI requests, especially for TDD

See merge request oai/openairinterface5g!708

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

 --> also adding TDD monolithic test at 20MHz with default scheduler
 --> putting IF4.p5 TDD scenarios with default scheduler
Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Fix cqi_req clear timing, and schedule PUSCH when CQI has not been received for a long time in fairRR scheduler.

In TDD mode, CQI requests are not possible in special subframes (at
least for some TDD configurations, see 36.213 7.2.3 that says "a
DL subframe is valid if it does not contain a DwPTS field if the
length is less than  7680 Ts").

In the code, we simply disable CQI requests in special subframes,
no matter what the length of DwPTS.

A problem can arise if the DCI0 for a given UE are sent only in
those special subframes. In this case the UE will never report
CQI and the eNB will use low MCS for this UE, impacting performances.

Another, related, problem is when there are several UEs. There again
one UE might always get its DCI0 in special subframes and thus never
report CQI. There again, performance issues.

This commit is an attempt to improve the situation.

It does two things.

1 - tag the UE as schedulable in the function UE_is_to_be_scheduled
    if the cqi_req_timer is expired

2 - use cqi_req_timer as a criterium when ordering UEs for UL scheduling

The value chosen for the expiration of the cqi_req_timer in
UE_is_to_be_scheduled is quite high (300) because as the code is
today we may overschedule the UE for short bursts until we receive
a CQI from the UE. [TODO: fix the code properly to avoid this behavior.]

Note: the fairRR scheduler has not been analyzed and this commit may
      not fix anything in case the fairRR scheduler is used.

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

	ACKNOWLEDGEMENT:
 	1. This commit was developed at Vicomtech (https://www.vicomtech.org) under UE project CDN-X-ALL: "CDN edge-cloud computing for efficient cache and reliable streaming aCROSS Aggregated unicast-multicast LinkS"
 	2. Project funded by Fed4FIRE+ OC5 (https://www.fed4fire.eu)
Signed-off-by: Javier Morgade <javier.morgade@ieee.org>

Signed-off-by: Javier Morgade <javier.morgade@ieee.org>

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.

simply ignore the error

maybe not the best solution

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.

	ACKNOWLEDGEMENT:
 	1. This commit was developed at Vicomtech (https://www.vicomtech.org) under UE project CDN-X-ALL: "CDN edge-cloud computing for efficient cache and reliable streaming aCROSS Aggregated unicast-multicast LinkS"
 	2. Project funded by Fed4FIRE+ OC5 (https://www.fed4fire.eu)
Signed-off-by: Javier Morgade <javier.morgade@ieee.org>

Signed-off-by: Javier Morgade <javier.morgade@ieee.org>

Develop Integration Branch: 2019 week 41

See merge request oai/openairinterface5g!689