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I believe Iridium also uses its satellite-to-satellite crosslinks for backhaul. In fact, the SpaceX proposal looks a lot like the Iridium concept in general, b
by azernik 9y ago
I believe Iridium also uses its satellite-to-satellite crosslinks for backhaul.
In fact, the SpaceX proposal looks a lot like the Iridium concept in general, but with thousands of little satellites instead of dozens of larger ones (which probably makes the implementation very different).
- kilroy123 9y agoWas going to mention the same. Half of their new constellations is up now. Apparently, you can use the commercially available hotspot devices that are out now. I'm curious how fast and well it will work.
- kevin_thibedeau 9y agoIt's Teledesic.
- azernik 9y agoHuh! Never heard of them before! (Which I guess is kind of the point.) Hopefully the telecoms market has changed enough since then (cf Iridium's recent profitability, even while launching a whole new constellation) to make it suddenly viable.
- Robotbeat 9y agoAnd SpaceX isn't trying to go for the mobile market. Fixed broadband only.
- dfox 9y agoThat makes technical sense. Original Iridium uses weird modulation scheme (which is also used as security-by-obscurity) for the sole purpose of having simple ground terminals, while Inmarsat in it's current generation is "bounce UMTS off GEO satelite" which requires either stationary or surprisingly complex ground terminals. SpaceX's network seems to work the other way around by being designed around fast-moving satellites and complex ground terminals that do the tracking and hand-overs by means of phase array antennas (ie. completely solid-state). In comparison to Inmarsat it is not GEO-bounce and in comparison to Iridium they seem to have some solution for having fully connected mesh of satellites (original Iridium is not fully connected sphere as there isn't even attempt to have link between satellites with oposite orbits)
- njarboe 9y agoAntenna as big as a pizza box. I believe I heard mentions of using it on cars (Teslas?) and other moving vehicles, like boats.
- Robotbeat 9y agoMobile uses (including cars) are only speculation at this point. License is for fixed, and only references have been to fixed.
- greglindahl 9y agoIridiumNEXT sats are 860kg. SpaceX's 2 test satellites were 400 kg.
- metaobject 9y agoBesides being much newer (and lighter components are now available), the electronics for a Free Space Optical system are much lighter than the electronics for an RF system. The concept 'Size, Weight, and Power' (SWaP) is commonly used when comparing FSO vs. RF systems. Incidentally, FSO systems have lower SWaP than RF systems. They're smaller and lighter payloads, and the system requires less poweR.
- lopmotr 9y agoA major difference is Iridium's 2.4kps which is nowhere near broadband, and no even dialup speed in the 90's.
- jessriedel 9y agoYou are comparing Iridium decade-old service to SpaceX's future service. A better comparison would be to the "Iridium Next" satellites, which are currently being deployed, will be available before SpaceX's service, and will increase bandwidth by more than two orders of magnitude (512 kbps). http://www.outfittersatellite.com/blog/iridium-next/whats-iridium-next-2.html http://www.outfittersatellite.com/blog/iridium-next/whats-ir...
- pooya13 9y agoI wonder if sites like google will launch their own orbital servers
- tcheard 9y agoUnless it is an Iridium handset to Iridium handset call, it will always be routed to one of Iridium's ground stations: - Arizona - Hawaii (Military only) - Russia and then it is routed through the fibre backbone. With the SpaceX proposal there will be more ground egress points, so it will be able to get closer to the destination before grounding.