I'm seeing a lot of people talking about Zello and other apps as backup communication during a disaster. Specifically how well this worked in Houston during Harvey. There's an important distinction to be made here.
In Houston, much of the communication infrastructure was still operable. Power stayed on to the cell towers and they still had connectivity. [1/5]
The problem there was that the telephony network was saturated. That network is designed around the notion that you get a guaranteed circuit, even if virtual, for that call. Put another way, if you place a call, it either goes through or it doesn't. There's no middle ground.
Internet connectivity is "best effort". That is to say, each router will fling your packet in the appropriate direction and hope for the best. [2/5]
For the most part this works surprisingly well, as demonstrated by the Cajun Navy. The occasional dropped packet just means a short gap in voice. Text messages can be retried automatically.
So the real question you have to look at for your area is: Will the cell towers be overloaded, or will your Internet go away entirely? If the former, you can probably still use Zello. If the latter, you'd better have some other options in mind. [3/5]
