This paper is a good summary: https://arxiv.org/pdf/1910.11002.pdf https://arxiv.org/pdf/1910.11002.pdf And of course all other unlicensed band users do this.

This paper is a good summary: https://arxiv.org/pdf/1910.11002.pdf https://arxiv.org/pdf/1910.11002.pdf And of course all other unlicensed band users do this. Again, this is a regulatory requirement. And ultimately, it is not just that you need to ensure others have access to the band, you also need to be robust in the face of persistent high interference given the number of users in the unlicensed bands. It's not a good fit for default LTE.