You have a bad habit of assuming that since it hasn't been directly addressed in the show, that something doesn't work at all.
You have a bad habit of trying to write for the series--filling in for the avoidance of reason.
What access to satellite communications has our little group had?
I'm talking about all characters--even more established groups like that seen at Woodbury, or an indivdual who was not living in primitive shambles such as Jenner at the CDC.
No excuses.
Do you think they should be sitting around watching satellite TV? (as if it would work)
...and exactly how did it all fall apart in mere days? Again, you cannot avoid the strong suggestion that society fell while Rick was in the hospital--and considering the peculiar habits of walkers, he would not have lasted for an extended amount of time.
So, tell us how society (including communications) fell so quickly.