-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 At sea systems get into $$$$, you have to track the satellite. Boats tend to pitch, roll and yaw. So, in order to compensate for this, and keep your antenna locked on a bird, you need to detect movement of the ship. Most the commercial stuff I've worked with has had a small roll/pitch gyro in it, and took heading from the ships compass. They fed all this to a computer which then positioned the antenna. These systems run the cost of a nice car, but you get TV at sea. Inmarsat is the same. With our systems we'd get 64kbit and it would run around 8 bucks a minute. Not sure with the new iridium stuff, but I still imagine it will be expensive. Again, still got to compensate for ships movement. You won't see them on small craft, as it's too cost prohibitive. For good signal strength, you'd need about a 1 meter dish, then you'd need to protect it with a radome. These things take up room, and there's not much above deck space on a sub 40 foot boat for one.
Mark Paul G. Allen wrote: > Lan Barnes wrote: > >> On Fri, Nov 18, 2005 at 11:04:08AM -0800, Paul G. Allen wrote: >> >>> FKI (for KPLUG's Information), we (QUAKE Global, Inc.) now have >>> modems capable of fairly high wireless bandwidth. They use both >>> satellite and cellular connections. Think of them like an external >>> dial-up modem only with DSL speed. Drawback - they're not cheap >>> (brand new product line means low quantity which translates to higher >>> production cost). >>> >>> We are also working on higher bandwidth, lower cost satellite modems >>> (think Iridium). For someone willing to put in the development >>> effort, these things have a great potential. >>> >>> PGA >> >> >> >> I should say! As a wannabe cruiser, the idea of having internet access >> on a sailboat in mid-Pacific is delicious. Not just a geek issue -- >> contact with friends and family (and emergency response), live weather >> feeds, and the ability to order parts and have them meet you at the next >> port of call. >> >> So how does this satellite thing work? Is the satellite company my ISP? >> > > It depends upon the network. We currently have ORBCOMM and Inmarsat D+. > Both of those are low bandwidth, small message size products mainly used > for asset tracking. Both are higher latency. With ORBCOMM you'd pay > someone else for the bandwidth, but the satellite company handles all > the traffic. With Inmarsat D+, you'd pay Satamatics (I think, I'm not > 100% sure which company provides the actual connection service) for the > connection. > > The cellular technology is akin to what Verizon and Cingular are now > providing for wireless broadband. The difference is these are data only, > and can fall back to ORBCOMM for lower bandwidth applications (e.g. - > e-mail). To connect via cellular, you would connect the modem to a > server on the Internet, there are a couple of companies that provide > service. Airsis is one of them. You could also connect to your own > computer through a direct IP connection (the modem must know the IP of > the server it's connecting to). The satellite side of it operates via > e-mail. I'm probably going to put one in my car one of these days > (though it would be easier if I had an SUV with room for a LCD monitor > and keyboard). > > 1Q 2006 we will be introducing our first Iridium product, of which I am > currently working on the software for. It's a more reliable network and > has the potential for higher bandwidth. > > Most of our "modems" have ARM7TDMI processors, 2MB of DRAM, a meg or > more of flash, and various I/O (analog, digital, RS-232, and I2C), and > onboard GPS. They can (and in most customer applications they are) be > used for data processing for things like SCADA, alarm systems, tracking, > e-mail, SMS, etc. We even have modems in space sending pictures of the > Earth back to ground stations. All but the Inmarsat D+ and our newest > modem (the Q1000 - the lowest cost satellite modem in the world) use > VxWorks as the OS. > > We're also looking at developing other products as well for higher > bandwidth, lower cost, and lower latency, and greater coverage area > (like the sailboat you mentioned). > > It's all a lot of fun, even more so since I just got a raise. > > PGA - -- Mark Wolfe Lakeside, Ca. http://www.wolfenet.org gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71 I've looked at the listing, and it's right! -- Joel Halpern -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDgCEm70b35oL2jHERAqjWAJ9baYc+g2kDRz1oCaFFcfdD2DDrZwCfW6dQ QBgDDmf56BFLOupgEFpD/sY= =C1yN -----END PGP SIGNATURE----- -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-list
