From 702c608ca1f0bafde7f6e432be36565bde9d2628 Mon Sep 17 00:00:00 2001 From: Robert Schmidt Date: Fri, 9 Feb 2024 11:49:47 +0100 Subject: [PATCH] O-RAN 7.2 doc: explain layer mapping, streamline start gNB section --- doc/ORAN_FHI7.2_Tutorial.md | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/doc/ORAN_FHI7.2_Tutorial.md b/doc/ORAN_FHI7.2_Tutorial.md index 6a810379fe..77e3ae69f3 100644 --- a/doc/ORAN_FHI7.2_Tutorial.md +++ b/doc/ORAN_FHI7.2_Tutorial.md @@ -622,17 +622,25 @@ Edit the sample OAI gNB configuration file and check following parameters: * `eAxC_offset`: PRACH antenna offset * `kbar`: the PRACH guard interval, provided in RU -xRAN SRS reception is not supported. The eAxC offsets for DL/UL are determined -from the antenna configuration. +Layer mapping (eAxC offsets) happens as follows: +- For PUSCH/PDSCH, the layers are mapped to `[0,1,...,N-1]` where `N` is the + respective RX/TX number of antennas. +- For PRACH, the layers are mapped to `[No,No+1,...No+N-1]` where No is the + `fhi_72.fh_config.[0].prach_config.eAxC_offset` and `N` the number of receive + antennas. + +xRAN SRS reception is not supported. # Start and Operation of OAI gNB +Run the `nr-softmodem` from the build directory: ```bash -cd ran_build/build - +cd ~/openairinterface5g/ran_build/build sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/oran.fh.band78.fr1.273PRB.conf --sa --reorder-thread-disable 1 --thread-pool ``` +You have to set the thread pool option to non-isolated CPUs, since the thread +pool is used for L1 processing which should not interfere with DPDK threads. For example if you have two NUMA nodes in your system (for example 18 CPUs per socket) and odd cores are non-isolated, then you can put the thread-pool on `1,3,5,7,9,11,13,15`. On the other hand, if you have one NUMA node, you can use