Scotty & Spock figured it out near the post-TNG timeframe and future Spock gives reboot Scott the solution. Just as an aside there's a hilarious Cracked post a

Scotty & Spock figured it out near the post-TNG timeframe and future Spock gives reboot Scott the solution. Just as an aside there's a hilarious Cracked post about how transwarp beaming obsoletes the Enterprise.