Re: [PLUG] wireless/ricochet

[Noah silva <nsilva@atari-source.com>]

I think it is the 2.4 that's ISM, and 2.5 that Metricom licensed.

from my docs:
"Metricom procured a limited amount of licensed spectrum that allows
higher transmit powers and thus greater coverage.  The disadvantage of
this spectrum (WCS) is that is was difficult to construct a transmitter
without physically large or overly expensive filters because of the
stringent limits on out-of-band emissions required by the FCC.  This
effectively limited the high power transmissions to WAP sites, thus
causing us to introduce a one-way asymmetric data link into our
architecture.  "

this would be the 2.5 (or whatever) licensed area of the spectrum.

"Finally, in order to reduce latency in the system, weadded the second FCC
Part 15.247 band at 2.4 GHz to the system.  The modem to MicroCell link
remained at 900MHz (better for building penetration and backwards
compatibility), while the backhaul to the WAPs was moved to the 2.4 GHz
band.  This allowed the MicroCells to become effectively full duplex, thus
increasing the throughput in the system by a factor of two (see fig. 9.)"

So, poletop to poletop is 2.4GHZ (the FCC Part 15.247 is the unlicensed
ISM stuff), WAP to poletop is on that band and also on whatever they were
able to license in a particular region (there are maps of this I have, and
I think it's 2.5Ghz in philly).  Subscriber to poletop is 900Mhz.

 -- noah silva 

On Fri, 17 May 2002, gabriel rosenkoetter wrote:

> On Fri, May 17, 2002 at 01:46:17PM -0400, Kevin Brosius wrote:
> > My reading suggested only the WAP model had the 2.4G support (top
> > antenna, on the 3 antenna model.)  Also, note that the 2.4G band is
> > licensed spectrum, so using it puts you at the risk of dealing with the
> > FCC.
> 
> It is?
> 
> Then how come 802.11B lives there?
> 
> And spread spectrum cordless phones?
> 
> -- 
> gabriel rosenkoetter
> gr@eclipsed.net
> 


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