[dreamcompiler]

In addition to all the above, phones move a lot during a call. You'd need very good sensors to keep track of the phone's orientation in space. If you're only shooting for 50%, the sensors in phones are probably good enough, but what happens when the user puts their head between the phone and the base station? The phone could say "please rotate your body to reconnect call" but that would be a lousy user experience.

[londons_explore]

There are neat tricks to keep phased array antennas in alignment. One for example is to just send the signal back in the same direction you're receiving from. (ie. Same phase delays in every antenna element)

Then however much the phone is tumbling, you'll always be exactly sending the data in the right direction.

Turns out the problem is moot anyway - unless you have a huge antenna to get a really narrow beam, sub-degree positional errors won't make any impact.