Merge remote-tracking branch 'origin/foxconn-doc' into integration_2025_w13 (!3331)

Add documentation for Foxconn RU

This MR adds documentation for using the Foxconn RU with OAI, as it piques the
interest of some in the community. Note that this RU is not continuously tested
with OAI L1. Additionally, we have observed throughput degradation in OAI
versions beyond tag 2024.w30, and the issue is under investigation. For now, we
are providing documentation based on what we have tested in our lab.

doc/ORAN_FHI7.2_Tutorial.md

@@ -72,6 +72,7 @@ tested any RU without S-plane. Radio units we are testing/integrating:
 |LiteON RU        |01.00.08/02.00.03     |
 |Benetel 650      |RAN650-1v1.0.4-dda1bf5|
 |Benetel 550 CAT-A|RAN550-1v1.0.4-605a25a|
+|Foxconn RPQN     |v3.1.15q.551_rc10     |
 
 Tested libxran releases:
 
@@ -671,6 +672,40 @@ The RU configuration is stored in `/etc/rumanager.conf`. The required modificati
 
 At this stage, RU must be rebooted so the changes apply.
 
+### Foxconn RPQN RU
+
+**Version v3.1.15q.551_rc10**
+
+The OAI configuration file [`gnb.sa.band78.273prb.fhi72.4X4-foxconn.conf`](../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4X4-foxconn.conf) corresponds to:
+- TDD pattern `DDDSU`, 2.5ms
+- Bandwidth 100MHz
+- MTU 8000
+
+#### RU configuration
+
+After switching on or rebooting the RU, the `/home/root/test/init_rrh_config_enable_cuplane` script should be run.
+
+The RU configuration file is located in `/home/root/test/RRHconfig_xran.xml`. The required modifications:
+1.  `RRH_DST_MAC_ADDR`
+2.  `RRH_SRC_MAC_ADDR`
+3.  `RRH_EAXC_ID_TYPE1`
+4.  `RRH_EAXC_ID_TYPE3`
+5.  `RRH_CMPR_HDR_PRESENT` -> `0`
+6.  `RRH_C_PLANE_VLAN_TAG`
+7.  `RRH_U_PLANE_VLAN_TAG`
+8.  `RRH_LO_FREQUENCY_KHZ` -> `3750000, 0`
+9.  `RRH_DISABLE_USING_CAL_TABLES` -> `YES`
+10. `RRH_TX_ATTENUATION` -> must be larger than 10dB
+11. `RRH_RX_ATTENUATION` -> must be lower than 30dB
+
+RU must be rebooted so the changes apply.
+
+**Note**
+
+- The RU was tested with the `2024.w30` tag of OAI.
+- The measured throughput was **520 Mbps DL** and **40 Mbps UL**.
+- With newer OAI versions, throughput degrades. This issue is currently under investigation.
+
 ## Configure Network Interfaces and DPDK VFs
 
 The 7.2 fronthaul uses the xran library, which requires DPDK. In this step, we