Date: Fri, 31 Oct 1997 00:01:07 +0100 (MET) From: lukas@design.de (Lukas Wunner) To: andrew@pubnix.net Cc: kbrown@primelink.com, tomthai@future.net, dnelson@slip.net, rgrimes@GndRsh.aac.dev.com, bad@uhf.wireless.net, danny@panda.hilink.com.au, freebsd-isp@FreeBSD.ORG Subject: Re: Wireless Services Message-ID: <m0xR3aN-000BijC@reactor.design.de> In-Reply-To: <Pine.BSF.3.96.971030170657.4617V-100000@guardian.fortress.org> from Andrew Webster at "Oct 30, 97 05:08:34 pm"
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Hi, > Excuse the interruption in your conversation. Actually at 2.4Ghz, you are > nearing the excitation frequency of water (2.5Ghz if your average > Microwave oven), you may see quite a bit of signal attenuation if there is > snow/rain. Exactly. The weather can have a considerable influence on the signal quality: - transmission quality is higher in winter (air seems to be clearer?) - if there's a lightning somewhere in the vicinity, transmission will stop completely for a few seconds > Of course if your transmitter is powerful enough, you can just punch a > hole in the weather. Here in Germany (or rather, in all ETSI countries), the EIRP regulations are very strict, so even with the 18 dBi antennas, you cannot go further than about 2.5 km. According to a guy from BreezeCom, in China there are no regulations whatsoever wrt transmission power, so these guys are more or less roasting the birds on their antennas. IIRC, the guy spoke of 60W. The US version has 1W if I am not mistaken. Lukas, proud owner of a BreezeCom system w/ those crispy 18 dBi antennas. :-) -- lukas wunner unix, internetworking and security engineer lukas@wunner.de LW26-RIPE http://www.wunner.de/~lukas/ Funkmodems mit 2.4GHz FAQ http://www.wunner.de/~lukas/funk/
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