I've been having the exact same issue. I spoke with Verizon and they were unable to help me. Anyone with a better answer than "CL"? (Turning off data connection doesn't get to the root of the problem.)
As far as I understand the wireless connection is the same as any wireless connection in your home. It means that that is all that is available because it is a busy time.
Try turning your wireless router off, wait 30 seconds, and then turn it back on. Depending on your router you might have a switch or you might have to unplug it. Some times the routers get "stupid" and need to be rebooted.