From a communications perspective, the aftermath of Hurricane Katrina was a real-life example of Murphy's Law: Everything that could go wrong, did. Not only did the storm's winds knock down a few towers, but even surviving towers were disabled due to the fact that many systems' electronics eventually were under water, lacked the power to operate, or did not have backhaul.

This unfortunate episode has forced everyone to re-evaluate the survivability and operability of communications systems, dealing with the question we all want to avoid: "What happens when nothing on the ground works?"

Probably the first alternative that comes to mind is satellite telephony from companies like Iridium. Certainly the satellite handsets were valuable in the immediate aftermath of Katrina, because the system does not rely on terrestrial infrastructure. When nothing else worked, they literally served as lifelines.

But the downsides of satellite phones are numerous. The service is expensive enough that some agencies won't be able to afford it, and handsets are pricey, so getting them into the hands of everyone who needs them can be difficult. More important, the current generation of satellite phones requires the user to hold the handset in a manner that maintains a link with the satellite.

For those working in a communications center, this isn't a big deal; for those out in the field trying to rescue people in far-from-ideal environments, it's a problem -- in fact, some first responders at Katrina chose to turn in their satellite phones rather than be frustrated by them.

It may be that the satellite phones are not as limited as some of the users indicated, because it's doubtful that there was a lot of time dedicated to training after the handsets were distributed. But there can be little argument on two points: first responders (and people, in general) prefer to communicate with the device they use on a daily basis, and the satellite phone technology available today is a decade old.

These points continue to nag me as we see various proposals to introduce broadband and interoperable communications systems nationwide. While most of them cite Hurricane Katrina as a reason for existing, only a few of these plans really address the need for non-terrestrial redundancy that will ensure communications exist when conditions bring even the most hardened terrestrial networks to their knees.

Where such redundancy is addressed, the typical solution is to overlay the terrestrial systems with satellite communications. On the surface, the strategy makes sense, but there are some practical problems.

Satellite phones require much larger antennas than those found on typical LMR or cellular handsets. That means first responders would need to carry an additional handset or a single handset that could communicate with both a terrestrial network and the satellite overlay network. Either way, we're talking about buying new handsets for everyone, which would get outrageously expensive.

Furthermore, the large investment associated with launching satellites dictates that they need to remain in use for at least 10-15 years to make economic sense. Proposals such as the one from Cyren Call recommend keeping this important communications system technologically "evergreen," but being tied to a single satellite technology for a decade would not seem to fit this vision.

An alternative to a satellite overlay is a system developed by Space Data, which uses weather balloons to suspend base stations in near space, 75,000 to 100,000 feet above sea level. Used for commercial vehicle tracking and in testing connected with U.S. Air Force communications, these balloon-supported base stations move very predictably at this altitude and can provide as much as 600 square miles of coverage, says Space Data CEO Gerald Knoblach.

Not only does the Space Data solution let users continue to use their existing handsets with no modifications, the base stations are brought back to earth when they reach the end of the coverage range and are launched again every few days.

"If you launch a satellite, you're stuck for 15 years with the technology that's in there the day you launched it -- and that's typically obsolete from the first day, because it took you two or three years to build a satellite and launch it," Knoblach says. "With ours, you can upgrade it every single day, so you can keep up with that Moore's Law path with consumer cell phones and electronics shrinking every day."

Space Data's solution is "typically 10 times lower cost" than satellite in a rural area and can be used to provide interoperability between disparate systems. In addition, the Space Data base stations are easy enough to deploy that additional balloons can be launched to provide extra capacity in a given area when it is needed.

Given these characteristics -- lower costs, no need to change existing handsets, interoperability capability, the ability to add capacity, and the flexibility to upgrade to new technologies in an ever-changing wireless marketplace -- the powers that be should give strong consideration to the weather-balloon solution when contemplating the best way to provide survivable communications redundancy.

E-mail me at donald.jackson@penton.com.