And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Could you even add 2 or 3 external antennae to the same unit?

Never understood this...

Well its much like anything else, not only are you going to change the
service area, but you are also changing the reception from your device,
which is often the important bit, as mobile devices have a limited power,
while the base could be quite high in power. It is very complex as the size
of the conductor, the length of the cable and the placement all affect the
polar diagram of the array as a whole, due to the phase relationships
perceived at the receiver. Some cancel out some add.
I think in the main they tend to do a suck it and see approach, just
tempput aerials around and see what the coverage is like. If its fine,
screw them down!

Its even more complex of course as there are a lot of different frequences
now and you have to cope with interference as well.
Brian

--
From the Bed of Brian Gaff.
The email is valid as
Blind user.
"Tim Watts" wrote in message
...
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Could you even add 2 or 3 external antennae to the same unit?

Never understood this...

In article ,
Tim Watts wrote:
Why do WIFI access points have 2-3 antennae?

http://en.wikipedia.org/wiki/MIMO

-- Richard

Tim Watts wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

With some with a single radio but multiple aerials it's just for
diversity, the AP is constantly trying both aerials to see which gives
best results and will then use that one for a while (to talk to a
specific device)

For others they can use multiple radios each with its own aerial, it
increases bandwidth, and the really clever ones use beamforming to 'aim'
the signal where it's wanted.

Could you even add 2 or 3 external antennae to the same unit?

If you fit external aerials, I don't think they like it if you fit them
a /long/ way apart, there's an assumption all the aerials cover roughly
the same area rather than different areas.

On 01/06/14 12:20, Richard Tobin wrote:
In article ,
Tim Watts wrote:
Why do WIFI access points have 2-3 antennae?

http://en.wikipedia.org/wiki/MIMO

-- Richard


Wow. OK - that is complicated... Thank you.

So should all the antennas point in the same axis?

On 01/06/14 13:48, Tim Watts wrote:
On 01/06/14 12:20, Richard Tobin wrote:
In article ,
Tim Watts wrote:
Why do WIFI access points have 2-3 antennae?

http://en.wikipedia.org/wiki/MIMO

-- Richard


Wow. OK - that is complicated... Thank you.

So should all the antennas point in the same axis?


nope. Its that magic word 'diversity'...



--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Sun, 01 Jun 2014 11:45:00 +0100, Tim Watts wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Nope.

Could you even add 2 or 3 external antennae to the same unit?

Yep.

Never understood this...

So long as the router does, that's all that matters...

On Sunday, June 1, 2014 11:45:00 AM UTC+1, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic added on at low cost to make the thing look more 'technological', like set-top TV aerials.

Owain

Ah diversity reception, I don't think most of these systems are that
sophisticated, as I say, its often the old we all know what SHOULD work but
in fact we need to put this here, and that over there to make it actually
work.. grin.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"The Natural Philosopher" wrote in message
...
On 01/06/14 13:48, Tim Watts wrote:
On 01/06/14 12:20, Richard Tobin wrote:
In article ,
Tim Watts wrote:
Why do WIFI access points have 2-3 antennae?

http://en.wikipedia.org/wiki/MIMO

-- Richard


Wow. OK - that is complicated... Thank you.

So should all the antennas point in the same axis?


nope. Its that magic word 'diversity'...



--
Ineptocracy

(in-ep-toc'-ra-cy) - a system of government where the least capable to
lead are elected by the least capable of producing, and where the members
of society least likely to sustain themselves or succeed, are rewarded
with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

I guess whether its snake oil or black box technology is according to your
take on the science and how applicable it is in the real built environment.

This is why you hear of people on mobiles who can only get a signal standing
on one leg on the edge of the bath.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Adrian" wrote in message
...
On Sun, 01 Jun 2014 11:45:00 +0100, Tim Watts wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Nope.

Could you even add 2 or 3 external antennae to the same unit?

Yep.

Never understood this...

So long as the router does, that's all that matters...

Do they still do that then?
I used a coat hanger for a tv aerial. Bent it into two squares, cut it in
half, connected the coax to the gap on one, then stapled it to a 9 inch bit
of wood. Joined the two ends of the other square, and stapled that to the
other end. Wallah, a set top aerial that was directional.
Brian

--
From the Sofa of Brian Gaff Reply address is active
wrote in message
...
On Sunday, June 1, 2014 11:45:00 AM UTC+1, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic added
on at low cost to make the thing look more 'technological', like set-top
TV aerials.

Owain

On 01/06/2014 17:28, wrote:
On Sunday, June 1, 2014 11:45:00 AM UTC+1, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic added on at low cost to make the thing look more 'technological', like set-top TV aerials.

Care to name a router with a dummy antenna such as you suggest?


--
Peter Crosland

Reply address is valid

On 01/06/14 18:00, Peter Crosland wrote:
On 01/06/2014 17:28, wrote:
On Sunday, June 1, 2014 11:45:00 AM UTC+1, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

Care to name a router with a dummy antenna such as you suggest?



My last HP laptop really had 2 antennae - I had to fit the WIFI module
because they messed up the order and supplied the module loose. There
were 2 aerial wires.

On Sun, 01 Jun 2014 09:28:55 -0700, spuorgelgoog wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

I think routers have gone the other way these days - even where external
antennae would actually improve reception, internal look "smoother" and
thereby better.

On 01/06/2014 20:50, Adrian wrote:
On Sun, 01 Jun 2014 09:28:55 -0700, spuorgelgoog wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

I think routers have gone the other way these days - even where external
antennae would actually improve reception, internal look "smoother" and
thereby better.

Have you some empirical evidence to substantiate your claim that
external antennas are better? Just because they don't protrude does not
mean they will significantly improve performance particularly at higher
frequencies. Patch antennas concealed within the surface work very well.


--
Peter Crosland

Reply address is valid

On Sun, 01 Jun 2014 21:12:21 +0100, Peter Crosland wrote:

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

I think routers have gone the other way these days - even where
external antennae would actually improve reception, internal look
"smoother" and thereby better.

Have you some empirical evidence to substantiate your claim that
external antennas are better?

Plenty to substantiate that they can, absolutely.

You'll note that I made no claim about the little stick things that come
as standard, but unscrewing those and putting a decent one on most
certainly can and does. As merely the most recent direct example, how
about the neighbour who swapped one of the stick things on his router for
a £15-delivered-from-Amazon TPLink antenna the other day, and can now
reliably get a connection from his garden office.

Or the business I used to work with, where we used a couple of similar
antennae to "bounce" a link between two offices in a serviced building
down the walls of an external alleyway, reliable enough for an office of
six or seven people to work with the servers that they couldn't otherwise
see.

Pity that isn't an option on routers with internal antennae.

In article ,
Peter Crosland wrote:
On 01/06/2014 20:50, Adrian wrote:
On Sun, 01 Jun 2014 09:28:55 -0700, spuorgelgoog wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

I think routers have gone the other way these days - even where external
antennae would actually improve reception, internal look "smoother" and
thereby better.

Have you some empirical evidence to substantiate your claim that
external antennas are better? Just because they don't protrude does not
mean they will significantly improve performance particularly at higher
frequencies. Patch antennas concealed within the surface work very well.

Mobile phones don't have external aerials any more.

--
From KT24

Using a RISC OS computer running v5.18

"Adrian" wrote in message
...
On Sun, 01 Jun 2014 09:28:55 -0700, spuorgelgoog wrote:

And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

I think routers have gone the other way these days

Nope.

- even where external antennae would actually improve
reception, internal look "smoother" and thereby better.

Both types are still readily available.

Tim Watts wrote:

My last HP laptop really had 2 antennae - I had to fit the WIFI module
because they messed up the order and supplied the module loose. There
were 2 aerial wires.

I can't remember the last laptop that /didn't/ have two antennas. They
may always have had two - I can't actually recall meeting anything else.
And my first wifi laptops had to use a PCMCIA card!

--
Scott

Where are we going and why am I in this handbasket?

Peter Crosland wrote:

Have you some empirical evidence to substantiate your claim that
external antennas are better?

I had to put extension cables on the card in my floor level desktop as
it couldn't see the floor level router. Would have been buggered if
they'd been internal ;-)

--
Scott

Where are we going and why am I in this handbasket?

On 02/06/2014 09:39, Scott M wrote:
Peter Crosland wrote:

Have you some empirical evidence to substantiate your claim that
external antennas are better?

I had to put extension cables on the card in my floor level desktop as
it couldn't see the floor level router. Would have been buggered if
they'd been internal ;-)


It would be easier to use a USB stick and an extension cable and its
probably cheaper.

On Mon, 02 Jun 2014 19:18:27 +0100, dennis@home wrote:

Have you some empirical evidence to substantiate your claim that
external antennas are better?

I had to put extension cables on the card in my floor level desktop as
it couldn't see the floor level router. Would have been buggered if
they'd been internal ;-)

It would be easier to use a USB stick and an extension cable and its
probably cheaper.

And for the situation I mentioned? Where the external antenna on the
router is being replaced to increase - measurably - coverage?

dennis@home wrote:
On 02/06/2014 09:39, Scott M wrote:
Peter Crosland wrote:

Have you some empirical evidence to substantiate your claim that
external antennas are better?

I had to put extension cables on the card in my floor level desktop as
it couldn't see the floor level router. Would have been buggered if
they'd been internal ;-)


It would be easier to use a USB stick and an extension cable and its
probably cheaper.

I think 1.98p for a couple of extension cables which also don't give me
USB limitations is tolerable. Oh, and cheaper.

--
Scott

Where are we going and why am I in this handbasket?

On 01/06/2014 11:45, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Could you even add 2 or 3 external antennae to the same unit?

Never understood this...


Some access points have 2 identical antennaes to provide diversity and
hopefully better Tx/Rx throughput, others (I have one) have 3 antennaes
and the '3rd' uses different frequency.
For optimum efficiency antennas have to be matched to wavelength ... so
if you have 2 specific frequencies one (usually best) option is a 2
matched antennae.

Although most cheaper access points just have one of more antennae
matched to a single frequency.

If you want to remote off an antennae ... you can do this as long as you
use correct impedance matched cable, and you either use a physical
ground plane, or a wire wound groundplane mimic.
If you don't know how important a ground plane is ... here is another
page for you:
http://en.wikipedia.org/wiki/Ground_plane

Even 2 strips of adhesive backed thick aluminium tape in a 'cross' with
antennae in middle can be good enough.
(often used on fibreglass structures)


--
UK SelfBuild: http://uk.groups.yahoo.com/group/UK_Selfbuild/

On 03/06/14 11:29, Rick Hughes wrote:
On 01/06/2014 11:45, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Could you even add 2 or 3 external antennae to the same unit?

Never understood this...


Some access points have 2 identical antennaes to provide diversity and
hopefully better Tx/Rx throughput, others (I have one) have 3 antennaes
and the '3rd' uses different frequency.
For optimum efficiency antennas have to be matched to wavelength ... so
if you have 2 specific frequencies one (usually best) option is a 2
matched antennae.

Although most cheaper access points just have one of more antennae
matched to a single frequency.

If you want to remote off an antennae ... you can do this as long as you
use correct impedance matched cable, and you either use a physical
ground plane, or a wire wound groundplane mimic.
If you don't know how important a ground plane is ... here is another
page for you:
http://en.wikipedia.org/wiki/Ground_plane

Even 2 strips of adhesive backed thick aluminium tape in a 'cross' with
antennae in middle can be good enough.
(often used on fibreglass structures)



Thanks Rick - most informative.

In article , Rick Hughes
scribeth thus
On 01/06/2014 11:45, Tim Watts wrote:
And if you wanted to add a remote antenna on a lead (for better antenna
placement), can you just add one and does it matter which of the 2 or 3
sockets you connect it to?

Could you even add 2 or 3 external antennae to the same unit?

Never understood this...


Some access points have 2 identical antennaes to provide diversity and
hopefully better Tx/Rx throughput,

Diversity is what is required this isn't a simple point to point link
environment.. Plane polarisation also gets badly skewed what starts as
Vertical is rarely that when it gets to where its required.


others (I have one) have 3 antennaes
and the '3rd' uses different frequency.
For optimum efficiency antennas have to be matched to wavelength ... so
if you have 2 specific frequencies one (usually best) option is a 2
matched antennae.

Although most cheaper access points just have one of more antennae
matched to a single frequency.

Around mid of the band of interest ..

If you want to remote off an antennae ... you can do this as long as you
use correct impedance matched cable, and you either use a physical
ground plane, or a wire wound groundplane mimic.
If you don't know how important a ground plane is ... here is another
page for you:
http://en.wikipedia.org/wiki/Ground_plane

Even 2 strips of adhesive backed thick aluminium tape in a 'cross' with
antennae in middle can be good enough.
(often used on fibreglass structures)


It can be better than nothing on vehicle roof's for VHF frequencies but
nowhere near as good as metal sheet..


--
Tony Sayer

On 01/06/2014 21:27, Adrian wrote:
On Sun, 01 Jun 2014 21:12:21 +0100, Peter Crosland wrote:

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological', like
set-top TV aerials.

I think routers have gone the other way these days - even where
external antennae would actually improve reception, internal look
"smoother" and thereby better.

Have you some empirical evidence to substantiate your claim that
external antennas are better?

Plenty to substantiate that they can, absolutely.

You'll note that I made no claim about the little stick things that come
as standard, but unscrewing those and putting a decent one on most
certainly can and does. As merely the most recent direct example, how
about the neighbour who swapped one of the stick things on his router for
a £15-delivered-from-Amazon TPLink antenna the other day, and can now
reliably get a connection from his garden office.

Or the business I used to work with, where we used a couple of similar
antennae to "bounce" a link between two offices in a serviced building
down the walls of an external alleyway, reliable enough for an office of
six or seven people to work with the servers that they couldn't otherwise
see.

Pity that isn't an option on routers with internal antennae.

Noted. But you are not comparing like with like. The "little stick
things" contain a metal antenna albeit a small one and are emphatically
not just for show as you suggest. The performance of a properly designed
patch antenna concealed within the casing will perform just as well as
one of those. Increasing the size of the antenna in the way you describe
will usually give performance gains.


--
Peter Crosland

Reply address is valid

On Tue, 03 Jun 2014 17:07:41 +0100, Peter Crosland wrote:

Of course, on some units the antennae may just be pieces of plastic
added on at low cost to make the thing look more 'technological',
like set-top TV aerials.

I think routers have gone the other way these days - even where
external antennae would actually improve reception, internal look
"smoother" and thereby better.

Have you some empirical evidence to substantiate your claim that
external antennas are better?

Plenty to substantiate that they can, absolutely.

You'll note that I made no claim about the little stick things that
come as standard, but unscrewing those and putting a decent one on most
certainly can and does. As merely the most recent direct example, how
about the neighbour who swapped one of the stick things on his router
for a £15-delivered-from-Amazon TPLink antenna the other day, and can
now reliably get a connection from his garden office.

Or the business I used to work with, where we used a couple of similar
antennae to "bounce" a link between two offices in a serviced building
down the walls of an external alleyway, reliable enough for an office
of six or seven people to work with the servers that they couldn't
otherwise see.

Pity that isn't an option on routers with internal antennae.

Noted. But you are not comparing like with like. The "little stick
things" contain a metal antenna albeit a small one and are emphatically
not just for show as you suggest.

I didn't make any such suggestion.

On 02/06/2014 19:39, Adrian wrote:
On Mon, 02 Jun 2014 19:18:27 +0100, dennis@home wrote:

Have you some empirical evidence to substantiate your claim that
external antennas are better?

I had to put extension cables on the card in my floor level desktop as
it couldn't see the floor level router. Would have been buggered if
they'd been internal ;-)

It would be easier to use a USB stick and an extension cable and its
probably cheaper.

And for the situation I mentioned? Where the external antenna on the
router is being replaced to increase - measurably - coverage?


Put the usb stick inside a piece of plastic drain pipe, cap the top and
screw it to the outside wall.

You will probably get more signal "gain" than the losses you get in the
down leads for an external aerial.

Some USB sticks can take an external aerial so you could even put one on
a few inches of cable and put that in the pipe too.

You could try
http://www.amazon.co.uk/Realtek-300M...words=wifi+usb
and £3 of pipe.