[151795] in North American Network Operators' Group
RE: airFiber (text of the 8 minute video)
daemon@ATHENA.MIT.EDU (Mark Gauvin)
Fri Mar 30 20:31:17 2012
X-Barracuda-Envelope-From: MGauvin@dryden.ca
From: Mark Gauvin <MGauvin@dryden.ca>
To: Greg Ihnen <os10rules@gmail.com>, Dylan Bouterse <dylan@corp.power1.com>
Date: Fri, 30 Mar 2012 19:30:30 -0500
In-Reply-To: <5F13D397-F0F9-4A96-8609-1B8E30B22653@gmail.com>
Cc: "'nanog@nanog.org'" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
that statement posted a few days ago saying that the former Motorola Canopy=
team designed this product turned me off right away
________________________________________
From: Greg Ihnen [os10rules@gmail.com]
Sent: Friday, March 30, 2012 6:36 PM
To: Dylan Bouterse
Cc: 'nanog@nanog.org'
Subject: Re: airFiber (text of the 8 minute video)
On Mar 30, 2012, at 6:01 PM, Dylan Bouterse wrote:
> A couple of thoughts. First, it's not fair to compare 24GHz to 2.4 or eve=
n 5Gig range due to the wave length. You will get 2.4GHz bleed through wall=
s, windows, etc. VERY close to a 5GHz transmitter you may get some bleed th=
rough walls but not reliably. 24GHz will not propagate through objects as i=
t's millimeter wavelength. That coupled with the fact it is a directional P=
TP product, you will be able to get a good amount of density of 24GHz PTP l=
inks using the same frequency in a small area (downtown for instance).
The comparison isn't on wavelength, it's on the unlicensed-ness of it. Thin=
k CB vs Ham Radio. Where 2.4GHz and 5.8GHz are congested people have no whe=
re to go but up. You may not be alone up there. Guys already running 24GHz =
links might look at the sudden availability of cheap 24GHz gear in a differ=
ent light.
Granted there's many things in AirFiber's favor regarding congestion being =
less of a problem. The short range and high directivity, high cost, etc, bu=
t remember this isn't the only 24GHz product out there. In the kind of plac=
es where one of these links might be needed, others might have the same nee=
d.
If you're thinking about the implications of possible congestion/interferen=
ce when you're thinking about a link between the main office and the wareho=
use at a plant to give the guys in the warehouse internet that's not missio=
n critical that's one thing. If it's key infrastructure for your ISP busine=
ss then things start to look different. The licensed links start looking be=
tter regarding reliability down the road because you have a protected frequ=
ency. For ISPs out in farm country this is less of an issue, but in the mor=
e urban areas it is a concern. You start getting interference to your backh=
aul and you've got serious issues. You possibly have downgraded service or =
no service at many towers involving lots of customers.
>
> Another point, the GPS on the airFiber will also allow for frequency reus=
e to a point. I would like to see smaller channel sizes though. I hear it w=
ill be a software upgrade down the road. I'm shocked the old Canopy guys di=
dn't code that into the first release to be honest.
The GPS/reuse thing is for transmitters that are synced, that is transmitte=
rs belonging to the same system. Someone else's system won't be synced with=
yours and you won't see that benefit. So if you're thinking that's going t=
o help between competitors it won't.
Greg
>
> Dylan
>
> -----Original Message-----
> From: Owen DeLong [mailto:owen@delong.com]
> Sent: Thursday, March 29, 2012 7:18 PM
> To: Oliver Garraux
> Cc: NANOG list
> Subject: Re: airFiber (text of the 8 minute video)
>
>
> On Mar 29, 2012, at 12:33 PM, Oliver Garraux wrote:
>
>>> Also keep in mind this is unlicensed gear (think unprotected airspace).=
Nothing stops everyone else in town from throwing one up and soon you're d=
rowning in a high noise floor and it goes slow or doesn't work at all. Like=
what's happened to 2.4GHz and 5.8GHz in a lot of places. There's few urban=
or semi-urban places where you still can use those frequencies for backhau=
l. The reason why people pay the big bucks for licenses and gear for licens=
ed frequencies is you're buying insurance it's going to work in the future=
.
>>>
>>> Greg
>>
>> I was at Ubiquiti's conference. I don't disagree with what you're
>> saying. Ubiquiti's take on it seemed to be that 24 Ghz would likely
>> never be used to the extent that 2.4 / 5.8 is. They are seeing 24 Ghz
>> as only for backhaul - no connections to end users. I guess
>> point-to-multipoint connections aren't permitted by the FCC for 24
>> Ghz. AirFiber appears to be fairly highly directional. It needs to
>> be though, as each link uses 100 Mhz, and there's only 250 Mhz
>> available @ 24 Ghz.
>>
>> It also sounded like there was a decent possibility of supporting
>> licensed 21 / 25 Ghz spectrum with AirFiber in the future.
>>
>> Oliver
>
> I don't think it's an FCC issue so much as 24Ghz has so much fade tendenc=
y with atmospheric moisture that an omnidirectional antenna is about as eff=
ective as a resistor coupled to ground (i.e. dummy load).
>
> The only way you can get a signal to go any real distance at that frequen=
cy is to use a highly directional high-gain antenna at both ends.
>
> Owen
>
>
>
>
