It's been months since its release but DICE is now opening up the Community Test Environment for Battlefield 4. DICE says that since the launch of the game, the "players have been pivotal in giving us valuable feedback." Now, they're opening the CTE to "engage with our fans in new ways."
The Community Test Environment (CTE) will provide passionate fans the chance to evolve Battlefield 4 with us and become a part of the development process. We’ll be able to test new ideas and solutions to current issues before we roll them out to all Battlefield players.

Among the first things we will work on is the “Netcode,” which is what the player experiences with the game world including player-to-player interactions like damage registration. This involves tweaking to the “tickrate” servers and networking in general.

By launching this new program, not only will we be able to address player feedback at an early stage, but also increase the overall quality of the game. We are excited to explore the possibilities together with you.

Better late than never?
How to Access the CTE
This community program will be available on PC only. However, the goal is for our learnings to benefit all platforms when possible. To access the CTE, you will need to be a Battlefield 4 Premium member. Players will have to download a separate game client, then connect to an infrastructure and Battlelog version solely set up for testing purposes.
  1. Visit http://cte.battlelog.com/bf4/communitytest/
  2. Read and accept the Terms of Service and Agreement
  3. Log into Origin with your existing account username and password (your account must have Premium activated in order to proceed)
  4. Start Origin and download the new Battlefield 4 CTE game client that now should be visible
  5. Install the Battlelog browser plugin
  6. Get familiar with the guidelines by visiting the Forums on http://cte.battlelog.com/bf4/forum/

Right now, only Premium members will be able to opt-in to this new service.