Lee H. Marzke on 26 Sep 2017 13:05:29 -0700

[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: [PLUG] odd wifi performance


Yes, the antenna's on both sides are very important ,  and typically the short ones
you get have no gain and send the signal out all directions ( a sphere ) which doesn't help much.
Remember the signal needs to be transmitted and received on both ends ( request / reply ) so if either end
doesn't have good antenna's you lose link speed or drop the connection.

If you use higher gain  (longer ) whip antenna's they flatten the signal vertically ( like a pancake ), or
panel antenna's shape the signal into a horizontally beam.   Officially the transmitter and antennas
are certified together by the FCC , so it's questionable if you can change them yourself legally
unless the replacement is from the same manufacturer, or you have an FCC license, or HAM license.

For instance you legally need to calculate the power of the transmitter + antenna gain is less
than the allowed Equiv Isotropic Radiate Power (EIRP).  (Point-2-MultiPoint < 4W EIRP)
I doubt anyone cares inside your house as this is designed to keep you from damaging nearby eyeballs
if you had a higher power transmitter coupled to a very directional antenna aimed at someones head.
See: https://www.air802.com/fcc-rules-and-regulations.html

If you need something better than what you have now I'd suggest not bothering with Antenna's as
good Antenna's and RF cables/connectors cost more than your tiny computer.

If you need better speed,  I'd suggest the AP units by Ubiquity which have very high speed and
range.   These units have very good Antenna designs for both xmit and recv from what I've
heard.   Note that these units use a horizontally steerable MiMO beam  towards your device and you can't
do that with any Antenna that you purchase.

They need a small Linux box running for management ( The web browser connects to
the management unit - not directly to the AP )

Note:  You don't lose much with pfSense running elsewhere.     Yes, you lose the ability for
a pfSense WiFi walled garden ,  but just put the Wifi unit in it's own vLAN ( network segment) and
use a new zone on pfSense for your rules.    The Ubuquity will likely support two SSID's so
one SSID can be internal, and one guest. Put those on separate  network segments, and  allow the
guest to get Internet only,  but not reach any computers in your house.

If you have any IOT devices, than you likely want a separate network segment for those as
well so they can't see or touch your house devices.   You have to assume that IOT devices will
be infected at some point.

I tend to use a cheep used Cisco switch ( with vLAN support ) rather than purchase separate
consumer switches for each LAN segment in the house.

FYI - I've put together some outdoor WiFi systems ( > 500 ft apart ) in the distant past and have an
commercial FCC General permit.


----- Original Message -----
> From: "Greg Helledy" <gregsonh@gra-inc.com>
> To: "Philadelphia Linux User's Group Discussion List" <plug@lists.phillylinux.org>
> Sent: Tuesday, September 26, 2017 2:25:27 PM
> Subject: [PLUG] odd wifi performance

> I have the miniature PC I posted about last week set up with PFSense as
> recommended here.  I have a lot to learn about how it works, but
> everything is good so far except for wifi performance.  It is running
> with 802.11g, and standing near the device, using my phone as a
> primitive signal meter, I get a signal strength of "very strong" and a
> link speed of 54 Mbps.  Two rooms away, where the TV and Amazon Fire
> Stick are located, I get a signal strength of "good", but a link speed
> of only 12 Mbps.  Does it seem odd that speed drops off that quickly if
> the signal is still "good"?
> I haven't tested what speed the Tomato router delivers at the TV, but
> it's clear that this new device is producing a weaker signal than the
> old one.  The wireless card is an AzureWave AW-NU706H, which is
> apparently an ok unit, but the supplied antennas have no markings on
> them...is it possible that these antennas are junk and replacing them
> would make a big improvement?  Anyone have any recommendations for
> replacement antennas?
> --
> Greg Helledy
> GRA, Incorporated
> P:  +1 215-884-7500
> F:  +1 215-884-1385
> www.gra.aero
> ___________________________________________________________________________
> Philadelphia Linux Users Group         --        http://www.phillylinux.org
> Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
> General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug

"Between subtle shading and the absence of light lies the nuance of iqlusion..." - Kryptos 

Lee Marzke, lee@marzke.net http://marzke.net/lee/ 
IT Consultant, VMware, VCenter, SAN storage, infrastructure, SW CM 
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug