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Technology Stocks : Winstar Comm. (WCII) -- Ignore unavailable to you. Want to Upgrade?

To: David Krafcsik who wrote (3116)	12/10/1997 9:32:00 PM
From: SteveG	Respond to of 12468

<I suppose it depends on what kind of modulation scheme they are using. It sounds like phase modulation, and I think they are limited to a set bandwidth by the FCC allocations, so they can't really change that. They could always increase the transmission power to ensure they had an adequate SNR (signal to noise ratio) for all possible weather conditions.> Communications isn't my forte, but I would have thought that power was more of a regulatory concern than bandwidth. And since I see WCII and others adding bandwidth almost monthly, I presumed THIS was the regulatory satisfying solution. <The key point is that at 38 GHz the variability in signal attenuation due to water in the atmosphere is much less than at say 28 GHz. Hence you wouldn't have to pump as much power through (means smaller power transmitters) and you probably wouldn't need as much dynamic range in your receiver.> Certainly makes sense. <Increasing the bandwidth to handle different types of interference sounds like a spread spectrum kind of approach. Is that what you were talking about? I don't think they can use spread spectrum because of the way these frequency bands are allocated.> Not really spread spectrum - more FDMA. I presumed that increasing the frequencies, depending on what modulations schemes are or can be used, would allow better transmission through specific noise bands, without increases in gain. But this was just a guess. Thanks for the response. Were the other references of any interest - especially if GAIN is NOT a regulatory consideration, details on the GaAs PHEMT chip? Regards- Steve