A simple question?

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I hope this is an easy question to answer.  
My situation: A new ASUS RT AC66W Router. I've tentatively set it up
for Ch 1 on 2.8 GHz  because the Ubiquiti AP I have is set for CH 6
and I can't seem to change that. I contacted ASUS support and after a
delay they came back and told me it was OK to set the ASUS on Ch 6
that there wouldn't be any conflict with the AP on the same channel.
That didn't sound right to me, so I thought I'd ask here. So, should I
set them both on the same channel (they are physically fairly close
but I need the AP to reach the far end of the house)? Or is it better
to have them on separate channels? The neighborhood is pretty crowded
on all the other channels.

Re: A simple question?
On Wed, 31 May 2017 14:26:49 -0500, Charlie Hoffpauir

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Nice router.  I have several.  The only problems so far are some
overheating if mounted horizontally (flat on table).

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You should be able to change any AP (access point) channel.  In
infrastructure mode, it's the AP that controls the channel and the
clients that just follow.  

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Wrong.  You won't have much of a conflict if one or the other AP is
not being used and not moving any data.  However, if both AP's a
moving data, you'll have collisions and retransmissions to deal with
if they are on the same channel.

Also, on 2.4GHz, there are really only 3 non-overlapping channels
available.  Those are channels 1, 6, and 11.  The signal is 25 MHz
wide and is 5 channels wide.  If you pick a channel in between 1, 6,
and 11, you will create interference to both the nearby
non-overlapping channels.
<http://www.metageek.com/training/resources/why-channels-1-6-11.html

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Oh-oh.  AP's don't have much in the way of selectivity.  A strong
signal ANYWHERE in the 2.4GHz band is going to cause reception
problems on any nearby AP.  Best to get some seperation, especially if
you expect to get some decent wireless speeds from your setup.  

Also, this begs the question, that if you have two AP's physically
close to each other, why do you need two AP's?  They will probably
have similar coverage areas.  You're certainly not going to run out of
capacity on a single AP.  I don't see why you need two.

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Seperate channels, preferrably lightly used.  If the band is
cluttered, use the 5GHz band.  The RT AC66W is a dual band router that
works quite nicely on both bands at the same time.  You'll get
somewhat less range on 5GHz, but because there will be far less
interference, you'll have better throughput.


--  
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Re: A simple question?
wrote:

Many thanks for your response Jeff. I'll try to answer a few things
you questioed.

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Thanks for that comment. I have it flat now, I'll change that to a
vertical mounting.
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I'd set up the Ubiquiti AP several years ago with my old router....
since changed (replaced) computer, and can't seem to get access to the
AP any more.  I have just enough technical knowledge to follow good
instructions, and can't find the original instructions.
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Well, with the old router, I couldn't get decent signal in the
kitchen, where I like to use the tablet in the mornings, so I added
the AP in the Den, which is near the kitchen, and got good wireless
signal. Have Cat 5 to the Den for the TV and satellite (Dish network)
box.

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I'm thinking with the new router, I have a better signal so I might be
able to simply take the AP out of service. I don't see anyone in the
neighborhood on 5 GHz, so that remains an option also.  

Re: A simple question?
On Wed, 31 May 2017 20:00:48 -0500, Charlie Hoffpauir

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You'll find quite a few comments on the overheating issue with a
Google search:
<https://www.google.com/#q=rt-ac66u+overheating
I also have one Asus RT-N66U (which I am now testing at home) which
has an even worse overheating problem.  With normal "room"
temperatures and vertical mounting, it's fine.  When the air
temperature hit 90F for a few days, and before I realized that
vertical mounting would help, the router would overheat and hang
several times per day.  

Also, make sure you have the latest firmware:
  Administration -> Firmware Upgrade -> Check
Mine shows:
  3.0.0.4.380_7378-g7a25649

If you're ambitious try one of the alternative versions:
<https://advancedtomato.com/downloads/router/rt-ac66u
<https://asuswrt.lostrealm.ca/features
I'm about to switch to the Merlin version so that I can run OpenVPN
and hopefully have a VPN setup between my office and home.

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It would be helpful if you disclosed the model number of your Ubiquiti
AP and the maker and model number of your router.  Extra credit for
firmware versions.  If the Ubiquiti whatever is that old, you might
look into a firmware update after you regain control.

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You should be able to find clues on the Ubiquiti web pile:
<https://www.ubnt.com/download/

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The lack of signal in the kitchen could be due to whatever antenna you
have plugged into the Ubiquiti AP is either wrong or pointed in the
wrong direction.  It also might be due to interference that's coming
from the neighbors through a window.  

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Installing ethernet cable (CAT5) for high traffic devices (TV, CATV,
satellite, media play, etc) will take the load off the wireless, be
faster, and be more reliable than wireless.  You did that correctly.

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Yep, that's exactly what I'm thinking.  My guess(tm) is that you could
do as well with just the Asus RT-AC66U wireless router.  Either way,
the last thing you want is having TWO routers in the system.  You'll
need to choose which router you want to have active and enabled.  I
could go on with a long rant on how to do this, but I suspect the
decision has already been made.  Remove the Ubiquiti AP and
unspecified model router, and leave the Asus RT-AC66U to do all the
work.  If anything requires speed (such as a media player or wireless
video streaming) use 5GHz as it's much faster.  (Note that 802.11AC is
all done on 5GHz).

--  
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Re: A simple question?
wrote:

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I may have misled you a bit, the old router has been out of service,
not a factor in any of this.
I've now removed the Ubiquiti AP from service and am using only the
ASUS router, set up for Channel 6 on 2.4 GHz. All seems well so far.

Checking signal strength with an Ap on my cell phone, gives me a -80
dB in 2.4 GHz vs -90 dB on 5 GHz (in the kitchen, with the router in
the far end of the house).

Re: A simple question?
On Thu, 01 Jun 2017 12:14:04 -0500, Charlie Hoffpauir

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Ok, got it.  If it helps any, I like to see:
1.  What problem are you trying to solve?  One sentence is just fine.
2.  What equipment and software do you have to work with?  Maker,
model, and version numbers are necessary.
3.  What have you done so far to solve the problem and what happened?
4.  Where are you stuck?

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Lousy signal levels.  You'll get a connection, but I don't think
you'll get anywhere near the speed you might expect.
<https://support.metageek.com/hc/en-us/articles/201955754-Understanding-WiFi-Signal-Strength
Scroll down to the chart at the bottom under "Ideal Signal Strength".
I try to aim for about -60dBm with -70dBm as a minimum for a reliable
connection.  Your -80 or -90dBm isn't even close.

Testing performance might be a good idea.  Download and install one of
the various mutations of iPerf on your unspecified model cell phone
(if it happens to be a smartphone).  The latest is iPerf3:
<https://iperf.fr/iperf-download.php
Next, find a PC, Mac, or Linux box and plug it into your RT-AC66W
router using an ethernet cable (not via Wi-Fi).  Install the
corresponding version of iPerf on this PC.  Setup the PC to act as a
server by running:
  iperf -s  
Run the speed test from your unspecified model cell phone and see what
kind of speeds you can get.  Move around and you'll probably see some
interesting changes in speed.  The basic idea is that this speed test
does *NOT* involve your internet connection speed.  At -80dBm, I would
guess(tm) that you'll get about 5Mbits/sec thruput with some dropouts.

In the future, you might want to have a subject line that has
something to do with your question or topic.  It's also helpful to
provide names and numbers of equipment instead of vague
generalizations, which force me to guess(tm).  The quality of the
answers you get are related to the quality of the information that you
provide.

For example, how many walls are you going through between the router
and the unspecified model cell phone?  How far, in feet or meters?
What's inside the walls?  Aluminum foil backed insulation perhaps?
Your weak signal might be due to simple attenuation.  Do you see the
problem?




--  
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Re: A simple question?
wrote:

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 1.Original question:  is it "better" to use a different channel for
an AP than the one the main router is on?  
2. Router: ASUS RT-66W AP: Ubiquiti UniFi AP (that's all it says for
model number) Cell phone: Samsung Galaxy S7 running a free Ap called
WiFi Analyzer.
Walls between router and location of WiFi reception (kitchen) 2
exterior and 2 interior. Interior walls sheetrock, exterior walls
brick.
Wall between location of Ubiquiti AP and kitchen: 1 interior.

Problem: slow response when using the tablet in the kitchen. Much
poorer internet response than I get from any of the computers, but the
computers connect via ethernet Cat 5.
  
(I got the AP because of low signal in the kitchen.... partly solved
by adding the Ubiquiti in the den, several years ago)
    
So far, after replacing the old router (Cradlepoint MBR-1000) I've
tried the ASUS wireless and with the Ubiquiti on (both on Ch 6 2.4
GHz), With the Ubiquiti off, with the Ubiquiti on Ch 6 and the ASUS on
Ch 1, and in terms of actual performance, I can't see much difference,
but that might be because my "broadband" internet service is so poor.
The internet service problem is unsolvable, I'm either stuck with the
WISP I'm using or switch to satellite, which I used to have and
discarded years ago.

From what I've learned so far;
If I have to use the AP and the router wireless, it's probably better
to have them on different channels, at least separated like 1 & 6.
My signal strength with the Asus wireless in the far end of the house
is marginal, so if I have any problems they could be resolved by using
the AP in the Den. For now, I'm running on just the ASUS. I'll try
that for a while, and compare to running with the AP.

Re: A simple question?
On Wed, 31 May 2017, in the Usenet newsgroup alt.internet.wireless, in article

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Suspected typ0 - 2.4 GHz - but OK

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They're correct.   802.11 wireless is not a "continuous" wave signal
(always on) - but sends it's data as a series of pulses. There is
plenty of space between those pulses for multiple stations to be
"talking" at the same time.

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Shouldn't be that much of a factor.

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Is is _better_ ?   Yes, but how much is the difference between 0.999
and 0.9995 ?   i.e. not a big deal.

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My laptop can see 11 networks on 2.4 GHz (3 on channel 1, 4 on channel
6, 3 on channel 11, and one for some reason setting on channel 10) and
that doesn't include the wireless security (TV) cameras blasting away
in the same band.  The router has logged as many as 16 hotspots on at
once.

        Old guy

Re: A simple question?
On Wed, 31 May 2017 23:07:23 -0000 (UTC), Moe Trin

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Only 16?  I was in a local high rise office building this morning.
Even through Low-E coated glass windows, which blocks Wi-Fi, I picked
up about 150 unique SSID's.  When I expanded the list to include
non-unique SSID's and list them by MAC address, it was about 240.  I
suspect that there are more, but I think 256 is the limit for the
number of MAC addresses that my sniffer can handle.  A histogram of
the channels in use showed every available channel had 10 to 30 access
points in use.  I think Ch 6 was the most used channel, which is why I
like to avoid Ch 6.  If I had been more interested, I would have run
Linux Kismet and also counted the number of client radios and IoT
devices.  The moral here is that the higher the altitude and the
better the view, the more garbage you pickup from other wi-fi systems.

Incidentally, the solution to this mornings wireless performance
problem was to move the various office access points away from windows
with a view of the city.  The inferference dropped substantially, and
the throughput improved.  Moving fixed devices to 5GHz also helped.

However, simply seeing a large number of AP's does not mean that the
system is useless.  When there's no traffic to move, the AP simply
beacons the SSID at 100 msec intervals.  There's really not that much
interference just from beacons.  The trick is to find a channel that
has rarely used access points.  These might be rather strong signals,
but if they're not used that often, they don't constitute much of an
interference source.  

The worst problems are the video cameras that you mention.  Most are
setup by default to use up every msec of allowable air time spewing
redundant pictures, where nothing moves, at the highest possible
speed.  The result is serious interference.  When I find these, I try
to encourage the owner to install an ethernet cable, usually by
demonstration that the quality of the picture is MUCH better at the
higher CAT5 cable rates.  If CAT5 or CAT6 are not an easy option, I
suggest they switch to 5GHz, which is less cluttered and allows faster
speeds.  Of course, I have a grab bag of replacement wired and
wireless cameras handy.

2nd worst are the media players and TV's, which are also commonly
connected via WiFi.  Same problem and solution as the wireless
cameras.

Gotta run... good luck.



--  
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

Re: A simple question?
On Thu, 01 Jun 2017, in the Usenet newsgroup alt.internet.wireless, in article


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We're out in the desert about 22 miles from city hall (but still well
within the city of Phoenix). Only a handful of neighbors (not like
where we used to live in Sunnyvale).

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And the nearest cameras (neighbors) are about 150 feet on either side.
I just took a tablet out into the street, and it can see 20 SSIDs.
In the house, it only sees five (stucco walls and Low-E windows).

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One of the SSIDs is "DIRECT-QZ-VIZIOTV", but the MAC address it is
using (02:6b:9e:) is bogus according to the IEEE site.  I shouldn't
complain, as my HP laptop says it's 00:00:83: (Rugged Systems Ltd used
to build a SPARC powered Tadpole net-book which ran SunOS or Sloaris).

        Old guy

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