10 Mbit/s problem in your network

Mon Feb 25 17:47:55 UTC 2013

If you want to see something pretty amazing, check this out..

http://www.popsci.com/science/article/2012-06/twisting-signals-vortex-researchers-beam-25-terabits-data-second

These guys got close to 100 bits/hz using Orbital Angular Momentum in addition to the normal Spin Angular Momentum. There is a picture out there of the I/Q showing the constellation, which to me looks like the future of communications systems. In my world, if you could offer 5 bits/hz or higher you would very likely be able to retire on your own island. Space segment for satellite systems can cost as much as 175k for 36MHz, so giving someone a 20x bandwidth increase would be an absolute game changer. Don't be surprised if you see the 802.11 guys trying to figure out how to make OAM work, it would essentially solve the worlds bandwidth problems at nearly all frequencies.

From: Owen DeLong <owen at delong.com<mailto:owen at delong.com>>
Date: Mon, 25 Feb 2013 08:56:05 -0800
To: User <wbailey at satelliteintelligencegroup.com<mailto:wbailey at satelliteintelligencegroup.com>>
Cc: Frank Bulk <frnkblk at iname.com<mailto:frnkblk at iname.com>>, NANOG <nanog at nanog.org<mailto:nanog at nanog.org>>
Subject: Re: 10 Mbit/s problem in your network

N has a number of advantages… Better spread, the ability to take advantage of polarization, better use of MIMO, and IIRC, a better encoding scheme that allows denser constellation points (more bits per signaling element).

N on 5Ghz takes advantage of the increased bandwidth of the 5Ghz channel where A merely replicated G on 5Ghz for all practical purposes.

Owen

On Feb 25, 2013, at 8:42 AM, Warren Bailey <wbailey at satelliteintelligencegroup.com<mailto:wbailey at satelliteintelligencegroup.com>> wrote:

I should probably know this, but doesn't N just spread better and have the ability to send receive on multiple polarizations? As an RF engineer I should probably know this, but I can't think of many people in my industry who really care about 802.11_. I really don't even use wireless in my house, though it's generally due to overcrowding the spectrum in populous areas.

>From my Android phone on T-Mobile. The first nationwide 4G network.

-------- Original message --------
From: Owen DeLong <owen at delong.com<mailto:owen at delong.com>>
Date: 02/25/2013 8:38 AM (GMT-08:00)
To: Frank Bulk <frnkblk at iname.com<mailto:frnkblk at iname.com>>
Cc: NANOG <nanog at nanog.org<mailto:nanog at nanog.org>>
Subject: Re: 10 Mbit/s problem in your network

Correct. However, while A is 5Ghz (only), it's not significantly better than G.

The true performance gains come from 5Ghz and N together. N on 2.4Ghz has
limited benefit over G. N on 5Ghz is significantly better.

Owen

On Feb 24, 2013, at 8:56 PM, "Frank Bulk" <frnkblk at iname.com<mailto:frnkblk at iname.com>> wrote:

> The IEEE 802.11n standards do not require 5 GHz support.  It's typical, but
> not necessary.
>
> Frank
>
> -----Original Message-----
> From: Owen DeLong [mailto:owen at delong.com]
> Sent: Sunday, February 17, 2013 2:07 PM
> To: Jay Ashworth
> Cc: NANOG
> Subject: Re: 10 Mbit/s problem in your network
>
>
> On Feb 17, 2013, at 08:33 , Jay Ashworth <jra at baylink.com<mailto:jra at baylink.com>> wrote:
>
>> ----- Original Message -----
>>> From: "Scott Howard" <scott at doc.net.au<mailto:scott at doc.net.au>>
>>
>>>> A VPN or SSH session (which is what most hotel guests traveling for
>>>> work will do) won't cache at all well, so this is a very bad idea.
>>>> Might improve some things, but not the really important ones.
>>>
>>> The chances of the average hotel wifi user even knowing what SSH means
>>> is close to zero.
>>
>> {{citation-needed}}
>>
>>> As an aside, I was sitting in JFK airport (terminal 4) a few days ago and
>>> having a shocking time getting a good internet connection - even from my
>>> own Mifi. I fired up inSSIDer, and within a few seconds it had detected
>>> 122 AP's...
>>
>> Yup; B/G/N congestion is a real problem.  Nice that the latest generation
>> of both mifi's and cellphones all seem to do A as well, in addition to
>> current-gen business laptops (my x61 is almost 5 years old, and speaks A).
>>
>
> I think by A you actually mean 5Ghz N. A doesn't do much better than G,
> though
> you still have the advantage of wider channels and less frequency congestion
> with other uses.
>
> Owen
>
>
>
>