Apparently Tokyo depends, a bit more that we are used to, on over-the-air, i.e. rooftop antennae, television signals.
For years, this was handled by the well-known 333 meters tall "Tokyo Tower" downtown.
Now, however, with the increasing number of tall neighboring buildings, and the advent of high-definition digital TV signals, that old tower cannot do the job.
(drumroll. . .)
Now, please meet the Tokyo "Sky Tree", 637 meters tall!