On Wed, Jul 9, 2014 at 8:53 PM, Scott Weeks <surfer@mauigateway.com> wrote:
Just to be fast, the article said 1.5Mbps Also, I completely missed that there was a page 2. It looks like they use Iridium. Here is some pricing. Just the first thing I found:
http://www.sattransusa.com/irprpl.html
Plan Monthly Amount Monthly Allowance Cost per 1000 Bytes Plan SBD 0 $27.00 0 Bytes $1.15 Plan SBD 12 $35.10 10,000 Bytes $1.05 Plan LBS 8* $28.78 8,000 Bytes $1.78
Hi Scott, If it's Iridium they aren't doing 1.5mbps. Iridium has Short Burst Data (SBD), a messaging service capable of sending and receiving a 2kB message a couple times a minute and they have RUDICS, a 1200bps or 2400bps (not kbps or mbps) synchronous serial service. They also have a product which gangs enough RUDICS channels together to get a 56k modem speed. Higher speed claims are "with compression." SBD is not used for Internet access, though it can be used for email. It's messaging, not packet data. What Iridium does have is coverage. Everywhere. Including both poles. They use a couple constellations of Low Earth Orbit (LEO) satellites with honest to god packet routing across the satellites to the ground stations. You don't need a stabilized high-gain antenna to talk to the satellites (they're only 500 miles up) and you don't have to be in the same footprint as a ground station. Basically, they're flying cell phone towers circa the mid-90's with microwave relays between them. This is very different from something like, let's say, Inmarsat. Inmarsat's satellites sit out at geostationary orbit, 23,000 miles away. More, they're a "bent-pipe" configuration. Your signal goes up on one radio frequency, is analog-shifted and comes back down at another radio frequency to the ground station that shares the footprint. On the other hand, since they're simple analog amps they've been able to recognize the kind of gains from tech that improved 9600bps phone lines to 7mbps DSL lines, and because they're not routing between satellites, each bird they fly has its own complete bandwidth. But I suspect an arctic icebreaker isn't using Inmarsat, with or without a stabilized three-meter antenna. Geostationary satellites have to fly around the equator. They wouldn't be stationary relative to the surface if they didn't. So, they kinda have trouble seeing the poles. There's also the odd fish like Globalstar. They have LEO satellites that are bent-pipes. This gives them limited coverage, and it's kinda weird -- your signal actually hits multiple satellites and ground stations and has to be deduped. Still, where it works it seems to work. Regards, Bill Herrin -- William D. Herrin ................ herrin@dirtside.com bill@herrin.us Owner, Dirtside Systems ............ Web: <http://www.dirtside.com/> Can I solve your unusual networking challenges?