Collaboration projects are open to all members, free of charge (except Catalyst projects). To join a project group you must register on www.tmforum.org, log in and and agree to the IPR mode that the project is operating under.  The project listing page is here 

Logging in to Confluence

• Once you have been approved to join the project (see Joining a Project above) you will be able to access the workspace for your project. This is called Confluence.
• To access the workspace navigate to www.tmforum.org and click the Collaboration menu item and select Collaboration Projects : https://www.tmforum.org/collaboration/current-projects/ and locate your project
• Click the name of the project
• As this is your first time accessing Confluence you will be taken to a login screen: 
  
• Here you can login using your www.tmforum.org username and password (your username will be your email address)
•  Tip: Click the "Remember Me" checkbox so that Confluence remembers your login for future visits