From 45827ee213d5e6e078a1ac14bfb6201ff1c8c4f2 Mon Sep 17 00:00:00 2001 From: Jaroslava Fiedlerova Date: Thu, 4 Dec 2025 15:42:34 +0100 Subject: [PATCH] Clarify doc for IF setup --- doc/RUNMODEM.md | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/doc/RUNMODEM.md b/doc/RUNMODEM.md index 6e46a361fe..640529cb61 100644 --- a/doc/RUNMODEM.md +++ b/doc/RUNMODEM.md @@ -468,19 +468,30 @@ The hardcoded DRBs will be treated like GBR Flows. Due to code limitations at th ## IF setup with OAI -OAI is also compatible with Intermediate Frequency (IF) equipment. This allows to use RF front-end that with arbitrary frequencies bands that do not comply with the standardised 3GPP NR bands. +OAI is also compatible with Intermediate Frequency (IF) equipment, allowing the +use of RF front-ends operating on arbitrary frequency bands that do not conform +to the standardized 3GPP NR bands. -To configure the IF frequencies it is necessary to use two command-line options at UE side: -- `if_freq`, downlink frequency in Hz -- `if_freq_off`, uplink frequency offset in Hz +### OAIUE configuration +To configure IF frequencies on the UE side, provide the following command-line +options: +- `if_freq`: DL frequency in Hz +- `if_freq_off`: UL frequency offset in Hz -Accordingly, the following parameters must be configured in the RUs section of the gNB configuration file: -- `if_freq` -- `if_offset` +### gNB configuration +On the gNB side, the corresponding parameters must be set in the RUs section of +the configuration file: +- `if_freq`: DL frequency in Hz +- `if_offset`: UL frequency offset in Hz + +> Note: When using a libconfig-based configuration file for the gNB, ensure that +> `if_freq` numeric value is suffixed with "L" so it is correctly parsed as +> 64-bit integer. ### Run OAI with custom DL/UL arbitrary frequencies -The following example uses DL frequency 2169.080 MHz and UL frequency offset -400 MHz, with a configuration file for band 66 (FDD) at gNB side. +The following example uses DL frequency 2169.080 MHz and UL frequency offset +-400 MHz, with a configuration file for band 66 (FDD) at gNB side. On two separate machines with USRPs, run: