Laser communications systems are wireless connections that work similarly to fiber optic links, except the beam is transmitted through free space.
The U.S. government's new Lasercom Interoperability Standard has been tested by Boeing, and demonstrated to the Military Satellite Communications (MILSATCOM) user community that it can rely on a 10 to 40 gigabit per second TSAT backbone between satellites. Just imagine that kind of bandwidth ..
TSAT is designed to provide the secure, long-haul, high capacity backbone and full Internet-like functionality for U.S. forces to ensure that they have information superiority in any situation throughout the world.
The Japanese Experiment Module "Kibo" on the International Space Station, which can now attach to & interface with the ISS, will carry the 1st laser communications experiments based on TSAT technology. This experiment will demonstrate large-capacity, high-data-rate (2.5 Gbps) two-way communications, between the ISS and ground stations.
As to what that means: Real-time voice communication, among other things.
- Talk about "lightning fast" wireless remote speech recognition ..
Across how many miles .. ??
One of our readers left a comment that asked:
" ..surely the latency is the same as laser and radiowave both travel the distance at the same speed? "
We posed this question to our leading wireless audio engineer.
Here's what our engineer replied with:
"Light travels at 3e8 meters per second or 186282 miles per second.
The ISS orbits at (approx) 220 miles from Earth:
220/186282 = latency @ 0.0011 seconds each way. Light and radio travel at about the same speed thru space. The latency from the Moon to the Earth would be 1.3 seconds, each way, for example. The data rate does not really come into play unless you are compressing the data so much that your codec adds up to 100ms of extra delay.
Ultra Wideband at 60GHz can do a few Gbps - but only has a range of 20 feet or so. It really comes down to available bandwidth and transmit power, and power loss thru the medium you are transmitting through.."
The NASA sources we put this question to appear to base their position on throughput.
They note that RF's maximum throughput (presently) is around 100mbps, per 802.11n, where laser communications offer bandwidth to 2.56 terrabits per second (presently).