The batteries are powered by solar panels. In either case the same arguments apply - space is notoriously low power.
Phones can't use directional antennas, otherwise you'd have to point them at radio towers. Using phased array antennas in which directionality is software controlled, there's a trade off between size of antenna and how much you can focus the beam - it wouldn't work in a phone (and would be too expensive anyway).
Phones can't use directional antennas, otherwise you'd have to point them at radio towers. Using phased array antennas in which directionality is software controlled, there's a trade off between size of antenna and how much you can focus the beam - it wouldn't work in a phone (and would be too expensive anyway).