In the configuration file, to enable measurements, add:

    enable_measurement_reports = "yes";

Note that if x2 is enabled then the option 'enable_measurement_reports'
is not taken into account and the measurements are enabled.

The following Merge Requests are included:

* MR 557 : Implement CDRX in FDD mode
* MR 571 : Improvement on documentation
* MR 572 : Fix CU/DU protocol split
* MR 574 : Fix a flexran free issue
* MR 578 : CI -- Improve OAI UE testing with USRP

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

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

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

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

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

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

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

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

 --> looping during the initOAIUE stage

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

* Instead of partly initializing in read_config_and_init(), everything of
  PDCP is initialized in main() of lte-softmodem
* Omit RC.rrc access in RRU through checking of RC.nb_inst > 0
* Includes FlexRAN, i.e. do not start FlexRAN in RRU
* Function pointers to PDCP functions have to be set explicitly (avoid
  confusion of multiply setting function pointers)

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

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

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

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

Merge branch '421-cdrx-for-lte' of https://gitlab.eurecom.fr/oai/openairinterface5g into 421-cdrx-for-lte

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

  -> slight increase on the ping RTT by 10 ms
  -> notification in the HTML report that CDRX was activated

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

Merge branch 'orange_cdrx_test' of https://gitlab.forge.orange-labs.fr/afyf6286/oai-orange into orange_cdrx_test

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

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