Contemplating the seemingly unthinkable
There is no shortage of watershed events in U.S. history, events that changed the course of history. Two that come immediately to mind are Colonel Jimmy Doolittle’s daring bombing raid on Tokyo, which shifted momentum to the U.S. in the Pacific during World War II, and President John F. Kennedy’s declaration in 1961 that America would place a man on the moon before the end of the decade, which delivered a sharp blow to the former Soviet Union during the Cold War.
The common denominator between these events is that in both cases the conventional wisdom was that it couldn’t be done. In Doolittle’s case, bombers had never before flown the distance they would have to fly to bomb Japan, more than 2000 miles. Also, none of the raiders had ever launched from an aircraft carrier before. In Kennedy’s case, America was well behind the Soviets in the space race; in fact, nine months would pass after the president’s declaration before the U.S. put its first astronaut into orbit.
Despite all of this, both of these previously unthinkable events not only occurred, but they did so with stunning impact. It makes me wonder whether another seemingly unthinkable event might one day be possible: satellite technology providing the basis for public-safety communications.
Imagine the impact that would have: no more terrestrial infrastructure to build and maintain; no more network outages because infrastructure has been rendered inoperable by natural or man-made disasters; and, perhaps, drastically reduced coverage and interference issues.
Of course, there are limitations inherent to satellite communications in their present form that preclude their use for mission-critical communications. For example, weather can wreak havoc with satellite signals, the so-called rain fade phenomenon. It’s the reason many people continue to get their TV service from more-expensive cable providers rather than the satellite providers.
However, satellite technology providers are finding solutions to weather-related interference, according to George Choquette, senior vice president of engineering for Hughes Network Systems. Choquette said Hughes can control how much downlink power its satellites transmit on a spot-beam basis to overcome the effects of weather.
“We get radar data from the National Weather Service and other sources, and when weather comes into an area, we step up the transmit power,” he said. “It’s pretty cool. Now, when the 30,000-foot thunder cloud comes in and it’s hailing, [communications cease]. But you can effectively use this technique with much more severe storms than any conventional satellite system.”
Latency and jitter are taboos in public-safety voice and video communications. But Hughes has addressed the latter, according to Choquette, by engineering into its system both constant-rate and on-demand bandwidth. “The satellite keeps track of how many of the connections are active at any particular time, and gives out slot-by-slot, packet-by-packet bandwidth to these terminals to service them,” he said.
In other words, the satellite can be programmed from the ground to allocate necessary bandwidth to public-safety terminals, essentially taking it from the general commercial pool when needed. “Not only is each terminal a router, the satellite is a router,” Choquette said.
Given the pace of technology evolution, it seems reasonable to think that the satellite technology developers will figure out a way to address other shortcomings, such as the fact satellite signals don’t penetrate buildings particularly well, which would be of utmost concern to first responders, particularly firefighters.
Hughes, SkyTerra (formerly Mobile Satellite Ventures) and TerraStar have launched, or will soon launch, giant satellites—“birds,” as they are known in the industry—that will allow form factors for satellite communications antennas and devices on the ground to shrink. Given that, let’s say, hypothetically, that these smaller-form-factor antennas are placed in every apparatus a fire department has. Would it be too far-fetched to think that, in the future, satellite communications from a remote command post or a dispatch center could be received by these in-vehicle satellite antennas, relayed through a gateway to an in-vehicle land mobile radio system that would then transmit the signal to firefighters on a peer-to-peer basis or via an in-building system?
I’m not an engineer, and I’m sure that some of our readers who are will scoff at this suggestion. But before you say it can’t be done, think back to Doolittle and Kennedy. And then think back to a decade ago. Did anyone 10 years ago think that IP-based communications ever would be used in the public-safety sector, for any reason? Or that satellite handsets one day would be in form factors similar to today’s cellular handsets and PDAs? Talk about the unthinkable.
What do you think? Tell us in the comment box below.
