To: Joe Brown who wrote (2859 ) 2/8/1999 11:23:00 PM From: Maurice Winn Read Replies (1) | Respond to of 29987
*Aerial Size* doesn't matter! It's what you do with it that counts. Well, that's what they told me when I asked. A big aerial, tuned to the right wavelength, picks up and sends more signal, more efficiently. But with a small aerial you can use smart alecky electronic gizzardry to enhance the signal so the aerial might be less efficient, but too bad - just waste a low-cost electronic component or two which people would rather pay for than lug around a big cigar thing on a little electronic box. With the first constellation, satellites will be 1414 kilometres high and as low as 10 or 15 degrees above the horizon, so the distance for the signal to travel is maybe 3 or 4,000 km. It takes some serious grunt to send a signal so far through rain, sleet and snow like some bedraggled postman making a "The Mail Must Go Through" heroic effort. With a poor aerial system, the battery would be drained to get enough oomph into the aether and up to the satellite. Neither would the handset be able to 'see' the weak signal coming back without a dirty great aerial sticking up like a flag pole. With Constellation 2, they will aim to have satellites 200 km high and 1,000 or them, so signal pathways will be maybe 300 or 400 km so a little aerial should be able to do the trick. With Qualcomm bringing out really clever little MSM3100 type ASICs, we can expect connectivity and battery life to go on improving. That's my theory anyway. Also, it means that Globalstar will totally wipe Iridium because Globalstar will have the coverage, the tiny internal aerial, the battery life, the excellent sound, the WWeb connectivity, the satellite to satellite connection [in the later constellations]. Iridium will be a technological blind alley. Iridium doesn't have the easy scalability of Globalstar, nor the access to Qualcomm's technology. It isn't just any old CDMA Iridium will be able to use while retaining high performance, building and rain penetration. Rah! Rah! Rah! Globalstar. Maurice PS: Thanks Valueman for the launch information. It seems that we are on the way to a constellation. That's fun. I'd love to watch it live on the Web though. Old third hand info in writing from flatoday.com is better than nothing, but not quite the real, 3D thing with stereophonic sound coming through my Qualcomm, WWeb, Anita [TM]. Ah, dreams.... [Okay, maybe 200 km and 1000 satellites is an exaggeration, but 600 km and 150 might be possible]