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Non Line of Sight Broadband
gfilion writes "IEEE Spectrum has an
article about nifty wireless adapters that don't require LOS. At first, NLOS wireless may not sound like a big deal. After all, ordinary radios and cellphones are non-line-of-sight devices. But they don't carry broadband data. What makes the latest generation of NLOS wireless technology worth talking about and having is that it delivers data at high rates over substantial distances."
Not. not by a long shot.
FM is Frequency Modulation. it is a mode of transmitting. what you are talinkg about FM or the 88-108Megahertz broadcast band, is not line of sight. that low of a frequency has both ground waves and sky-waves. this is how in west michigan I can recieve WLUP Chicago on 97.9MHZ easily by swinging a directional gain antenna in that direction. Also, Frequencies from 88MHZ up past 450MHZ also can take advantage of tropospheric ducting.
Line of sight doesn't start until past 1.2 GHZ 802.11 equipment at 2.4ghz act like line of sight outside because of water vapro and water bearing items (leaves, squirrels, children) suck up large amounts of signal..
so NO FM is not line of sight. not in the correct term nor in your definition.
Do not look at laser with remaining good eye.
Modulation schemes have nothing to do with whether a particular transmission is line-of-sight or not. Carrier frequency does. I assume by "FM radio" you mean commercial broadcast FM as in 88-108 MHz. Why then was I receiving 96.5 WFLB (which is in Fayetteville, NC) in Richmond, VA the other morning (which has a 96.5 of its own)? Hint - Tropospheric Ducting (or tropo-ducto, as I call it, since it's nearly indistinguishable from magic - presto-chango and all that).
In general, as frequency increases, so does the line-of-sight nature of the RF. Light, being extremely high frequency RF, is very much line-of-sight. AM Radio, being between 540 kHz and 1600 kHz, can span the globe because of groundwave bending and ionospheric ducting. Amateur radio operators deal with lots of different propagation modes all the time.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
I work for an ISP in a rural area. People call up all the time because they signed up for AOL and then they got their first phone bill and... you know the rest. But quite a few actually insist on keeping their AOL service even though we provide the same thing but without the flashy software with the "you got mail" WAV file. So they're will to pay us $18/month and whatever AOL is charging for an outside ISP account now ($10?).