Eduroam is an Internet access service for academics. In most universities and research center, there is a WiFi Eduroam one can connect to for free.

First, you need to sign up, with “annuaire UPMC” credentials. There is no need to be within the campus to sign up, you can sign up while you're traveling.

For Mac/Windows/Linux:

• Go to https://cat.eduroam.org/
• Click on “Download the Eduroam installer”
• Choose UPMC in the list
• Continue. UPMC id/password are requested.
• A certificat is now installed on your computer.
• To connect to Eduroam, simply click on Eduroam in you Wifi manager. Authentication is automatic.
  

For iPhone/Android, there is a similar procedure, but it didn't work on my Android 9 (Max, 06/07/2019).