5G Quectel KPI AT ROS1 & ROS2

Author: Emanuele Pagliari

This ROS1 package gathers the main 5G RF quality indexes from Quectel 5G modems (Tested on RM520N-GL) and publish them in the proper ROS1 topic (quectel_nr5g).

The ROS2 porting is available in the ROS2 folder.

Requirements

The only requirements are Python3 with its related ROS1 dependencies and pySerial installed. Also, a Quectel 5G modem properly connected to the host computer is needed with a good quality USB-C 3.0 cable.

First connection 5G modem setup

If the the 5G modem, not only Quectel RM520N-GL but also the Sierra Wireless EM9293 and EM9191 have never been used on the robotic platform or computer, it might be needed to upgrade both ModemManager as well as NetworkManager, plus to setup the connection in NetworkManager.

To install and update ModemManager, run the following command:

snap install modem-manager modem-manager

To update NetworkManager, run the following command:

sudo apt-get install network-manager

A reboot is recommended after the installation of these dependencies.

Once they are installed, the 5G modem is going to be detected and visible from the network setting menu. However, I reccomend to setup the cellular connection and APN using the following command:

sudo nmcli connection add type gsm ifname '*' con-name '5GSA' apn '5gsa.lulea' connection.autoconnect yes

where con-name '5GSA' is the name of the connection that you want to add, while apn '5gsa.lulea' is the APN for the 5G network at LTU. These parameters must be set accordendly to the cellular network you want to connect to. As an example, Telia parameters APN is apn 'online.telia.se'.

Selecting modem operating mode

The developed ROS1 and ROS2 package in this repository works only to gather 5G KPI. Using this package with 4G network will crash the script or result in no output in the ROS topic, since the parser process only the 5G-related RF metrics.

Therefore, it is needed to force the modem to 5G SA only, thus excluding the fallback on 4G LTE tecnology. In order to do this, after the modem has been setup, it is possible to force the 5G SA only operating mode trough the following ModemManager commands.

First of all, the target modem must be individuated. To do this, the following command can be used:

mmcli -L

It will output the available connected modems, in our case the Sierra Wireless EM9293:

/org/freedesktop/ModemManager1/Modem/0 [Sierra Wireless] EM9293

Then, using its ID, it is possible to force the 5G SA only modem operating modem likes follow:

mmcli -m 0 —set-allowed-modes='5g|none'

An output should appear based on the used modem.

Output example

To do

Modify the parser and the publisher to include more data.

Known issues

A proper boot sequence for the modem is needed, otherwise the AT ports will not be available. Troublwshooting in progress ...