I also wonder with MIMO systems why the V/H or -45/+45 polarities are
not considered separate transmitters (because they are). In which case
each one should be allowed up to the limit?
AND... What allows UBNT to transmit at up to 27 dbm, yet PMP450 is
limited to 22 dbm? What's different there that I don't understand? 5
dbm is a bunch in my book. Is it OOB that is the issue here?
bp
<part15sbs{at}gmail{dot}com>
On 3/10/2015 10:23 AM, Ken Hohhof wrote:
Personally I also feel there is a flaw in the way EIRP is regulated on
FHSS systems. The limit in 900 MHz is on total EIRP, not power
spectral density. Somehow the FCC feels it is OK to concentrate 4
watts in one narrow hopping sub-channel as long as the dwell time
isn’t too long. That’s like saying you can use a magnifying glass to
concentrate sunlight on a single ant and it won’t hurt the ant as long
as you move it to a different ant every second. No, you end up with a
bunch of smoking ant carcasses on the sidewalk.
Also the smartgrid mesh networks seem to violate the spirit of the
requirement that you can’t get around the EIRP limit by using multiple
transmitters to send the same data, for example in a MIMO system.
*From:* Jeremy Grip <mailto:[email protected]>
*Sent:* Tuesday, March 10, 2015 12:10 PM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [AFMUG] More LTE tradgedy of the commons on 5 GHz..
+1
*From:*Af [mailto:[email protected]] *On Behalf Of *Peter Kranz
*Sent:* Tuesday, March 03, 2015 12:02 PM
*To:* [email protected]
*Subject:* Re: [AFMUG] More LTE tradgedy of the commons on 5 GHz..
I think the point some are missing is the lesson learned from 900Mhz
and smart meters.
While 900Mhz is unlicensed spectrum, a single operator has managed to
take it over in California to the point where no other user has any
chance of using the spectrum for commercial purposes.
By this I mean that PG&E’s deployment of smart meters on every power
meter in the area, and on top of power poles, and other high sites,
has raised the noise floor on this band to unusable levels for high
speed communications.
So by means of overwhelming numbers, PG&E managed to take over 900Mhz
for its own users, stranding the investment of ISPs in this spectrum
in affected markets. I don’t think the commissions initial concept of
unlicensed spectrum was that a single operator would do this, I think
they expected operators by this to use licensed spectrum.
I’d like to see a limit on how many systems a particular entity can
deploy in an unlicensed band. It could be some high number, like 1
million units.
*Peter Kranz
*Founder/CEO - Unwired Ltd
www.UnwiredLtd.com <http://www.unwiredltd.com/>
Desk: 510-868-1614 x100
Mobile: 510-207-0000
[email protected] <mailto:[email protected]>
