In reading Andy Opsahi’s article Satellite Technology Provides Disaster Communications When Cell Towers Fail at http://www.emergencymgmt.com/disaster/Satellite-Technology-Provides-Disaster.html, I was at first heartened with the statement:
Emergency managers know that having foolproof disaster communications plan is nothing more than fantasy. That’s because even the most redundant backup strategies can leave responders unable to communicate.
Unfortunately, Andy missed two major drawbacks to satellite communications in the article that appears bias toward the positives of using satellite. It isn’t surprising as they are frequently overlooked. A clear view of the sky, and the spot beam capacity. Although he was dead on when he said it was expensive.
All satellite devices need clear view of the sky. Depending on the orbit and other factors, it may require specific view or large view of the entire sky. Satellite pagers/trackers are nice, but dead weight when the end-users stuff them in the backpack.
A handheld satellite phone is the same way. The user will need to get out of the vehicle or building to see the sky. This could also expose them to whatever broke their primary communications in the first place. I’ve lost count of how many people have complained about satellite phones haven’t worked, only to learn they didn’t followed the first direction: have clear view of the sky. Imagine asking first responder in tall urban location to find clear view of the sky.
Sales people will commonly talk about the capacity of the end-user device or the satellite as whole. Few get into the technical details about the capacity of the spot beam. A satellite’s view is usually broken down into individual spot beams. This allows the satellite owner to geographically segment users on the same frequency to get more capacity out of the satellite. The user in Calfornia doesn’t interfere with the user in Texas, who doesn’t interfere with Florida and so on. Spot beams can range in size to where the lower-48 United States would take up to 30 spot beams to cover it. This usually doesn’t cause an issue since the expectation is that the users are equally spread out geographically. And the satellite can be designed to have more spot beams focused on higher use areas. The downside occurs when people from all over the county converge on single area and overload spot beam. Think of all the people who respond to catastrophic disaster, oversee the presidential inauguration, or cover national sporting event. During these times, everyone is going to yank out their satellite phone, BGAN or whatever. They’ll learn that the satellite in space gets just as overwhelmed as the cell tower a few miles away.
My recommendation is to go back to Andy’s first statement in the article. Even redundant communications can fail. Satellite technology is only the “technological catnip” for people who are looking for quick buzz-word solution. The rest of us toss it in our bag of tricks as yet another solution that we can call on.