Effectiveness of indoor antenna?

I've recently been asked to install some wireless networking kit at a
very large, old country house.

I visited the house yesterday to perform a site survey and take a look
at the requirement. The two key places which require wireless access
are literally in opposite sides of the house. Being a very old
building, there is no structured caballing and the route from room A to
room B would be very difficult to cable.

I have set up many wireless LANS, using single router/ap combos and
also larger WLAN's using multiple APs caballed back to a
router/switch. I haven't until now configured a WLAN with additional
antenna and I'm looking for guidance and advice.

If I was to purchase Buffalo access points and attached a directional
antenna, would this likely penetrate multiple walls. The other idea, is
for me to point the antenna out of the window, towards the other side
of the house.

I know it is hard to say how well an antenna will perform, without
knowing distances and the construction of a property, but are they
effective at extending signal, where the line of site is broken with
walls/glass or other obstacles.

Any suggestions or advice would be greatly appreciated.

"Chrishow" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
| I've recently been asked to install some wireless networking kit at a
| very large, old country house.
|
| I visited the house yesterday to perform a site survey and take a look
| at the requirement. The two key places which require wireless access
| are literally in opposite sides of the house. Being a very old
| building, there is no structured caballing and the route from room A to
| room B would be very difficult to cable.
|
| I have set up many wireless LANS, using single router/ap combos and
| also larger WLAN's using multiple APs caballed back to a
| router/switch. I haven't until now configured a WLAN with additional
| antenna and I'm looking for guidance and advice.
|
| If I was to purchase Buffalo access points and attached a directional
| antenna, would this likely penetrate multiple walls. The other idea, is
| for me to point the antenna out of the window, towards the other side
| of the house.
|
| I know it is hard to say how well an antenna will perform, without
| knowing distances and the construction of a property, but are they
| effective at extending signal, where the line of site is broken with
| walls/glass or other obstacles.
|
| Any suggestions or advice would be greatly appreciated.

Set the AP outside the house using a cardioid antenna pointing that the
house. You can adjust the orientation/tilt of the antenna for the best
performance.

Without a doubt directional antennas work & help penetrate.
Here they've proven appreciably better than omni's of same db, amazing
difference.
especially with directional on both ends ,,, which has been outstanding
here.
unless of course I want a virtual line of site to pass through the metal
lathe&plaster walls here, then things are just really weak.

"Chrishow" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
> I've recently been asked to install some wireless networking kit at a
> very large, old country house.
>
> I visited the house yesterday to perform a site survey and take a look
> at the requirement. The two key places which require wireless access
> are literally in opposite sides of the house. Being a very old
> building, there is no structured caballing and the route from room A to
> room B would be very difficult to cable.
>
> I have set up many wireless LANS, using single router/ap combos and
> also larger WLAN's using multiple APs caballed back to a
> router/switch. I haven't until now configured a WLAN with additional
> antenna and I'm looking for guidance and advice.
>
> If I was to purchase Buffalo access points and attached a directional
> antenna, would this likely penetrate multiple walls. The other idea, is
> for me to point the antenna out of the window, towards the other side
> of the house.
>
> I know it is hard to say how well an antenna will perform, without
> knowing distances and the construction of a property, but are they
> effective at extending signal, where the line of site is broken with
> walls/glass or other obstacles.
>
> Any suggestions or advice would be greatly appreciated.
>

"Chrishow" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
> I've recently been asked to install some wireless networking kit at a
> very large, old country house.
>
> I visited the house yesterday to perform a site survey and take a look
> at the requirement. The two key places which require wireless access
> are literally in opposite sides of the house. Being a very old
> building, there is no structured caballing and the route from room A to
> room B would be very difficult to cable.
>
> I have set up many wireless LANS, using single router/ap combos and
> also larger WLAN's using multiple APs caballed back to a
> router/switch. I haven't until now configured a WLAN with additional
> antenna and I'm looking for guidance and advice.
>
> If I was to purchase Buffalo access points and attached a directional
> antenna, would this likely penetrate multiple walls. The other idea, is
> for me to point the antenna out of the window, towards the other side
> of the house.
>
> I know it is hard to say how well an antenna will perform, without
> knowing distances and the construction of a property, but are they
> effective at extending signal, where the line of site is broken with
> walls/glass or other obstacles.
>
> Any suggestions or advice would be greatly appreciated.
>

Old houses tend to have at least 18" thick walls.
Trying to get through the walls sounds unlikely to me unless the doors line up.
Antennas outside the building in line of sight.
Networking over mains, provided it isn't a different mains phase in the two areas.
Data rates are limited at present over mains but may be acceptable.

Let us know how you go on.

eric

--
Remove the dross to contact me directly

On 27 Jun 2005 13:41:50 -0700, "Chrishow" <(E-Mail Removed)>
wrote:

>I've recently been asked to install some wireless networking kit at a
>very large, old country house.

Wood, brick, lath-n-plaster, construction?
One floor, two floors, big windows, small windows?
Totally flat or on a hillside? Basement? Attic?
Online photo? Numbers? Details?

Am I being sufficiently subtle? There's no such thing as a universal
solution that will work for all types of building, construction,
layout, topology, and topography.

>I visited the house yesterday to perform a site survey and take a look
>at the requirement. The two key places which require wireless access
>are literally in opposite sides of the house.

Is the building floor plan squareish, or elongated? How far are the
two key places at opposite ends of the house?

>Being a very old
>building, there is no structured caballing and the route from room A to
>room B would be very difficult to cable.

I'll take your word for that, but I've found that buildings with
outside plumbing are very easy to cable. I try to sell the owner on
wiring the house for cable TV, telephone, bunglar alarm, thermostat,
intercom, etc at the same time. See comp.dcom.wiring for hints.

>I have set up many wireless LANS, using single router/ap combos and
>also larger WLAN's using multiple APs caballed back to a
>router/switch. I haven't until now configured a WLAN with additional
>antenna and I'm looking for guidance and advice.

You've led a sheltered life. Welcome to wireless hell. The real
secret to successful wireless is to get a clear line of sight. NLOS
(non line of sight) solutions are at best a crap shoot. Shooting
*THROUGH* a building or house is one of the best ways of guaranteeing
repeat visits to "optimize" the wireless. You might be able to make
it work today, but as things move around the house, the path will
change. I strongly suggest you avoid shooting through a house. If
you must do so, then place the access point at one end of the house,
attach a fairly large panel antenna (14dBi gain 35degree beamwidth)
and point it towards the other end of the house. If possible, shoot
it down a hallway. Your level of success will be limited by the
number of walls the signal has to smash through. I've found 3 to be
about the limit. If the walls have aluminum foil backed insulation,
give up now.

>If I was to purchase Buffalo access points and attached a directional
>antenna, would this likely penetrate multiple walls.

2.4GHz doesn't penetrate walls very well. It sneaks through cracks,
hallways, windows, and doorways. As a rule of thumb, one wall is
usually possible, 2 walls is a potential problem, 3 walls is totally
unreliable. Again, you can probably find a location at opposite ends
of the house that will work, but you will not be able to keep it
working at that location.

>The other idea, is
>for me to point the antenna out of the window, towards the other side
>of the house.

Well, if the house layout allows such a system (i.e. dog-leg or L
shape), then by all means, this is the way to go. Shoot through the
windows. However, if the windows have been retrofitted with
aluminized mylar for energy efficiency, it won't work at all.
Incidentally, locating the access point outside and shooting through
windows is the preferred way to do hotels and apartments, where inside
clutter would block the signal. I did a large mansion long ago by
installing the access points in various outside locations (including a
tree) and pointing the antennas toward the large glass windows.
Biggest problem was the gophers chewing up the waterproof CAT5.

>I know it is hard to say how well an antenna will perform, without
>knowing distances and the construction of a property, but are they
>effective at extending signal, where the line of site is broken with
>walls/glass or other obstacles.

Yep. If structure attenuation were your only problem, it would be
easy to calculate. The real problem is reflections. There's no
guarantee that your path through the building maze will go via a
single stable path. It will bounce around and create multipath, the
eternal enemy of reliable wireless. Try to think of this as an
exercise in increasing the fade margin.

>Any suggestions or advice would be greatly appreciated.

Run the wires if possible. Otherwise, try illuminating from the
outside. Do NOT bother trying to shoot through the building unless
your site survey shows a very strong signal or you have RF transparent
inside (glass?) walls.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Thanks to everyone for their advice and recommendations, in response to
Jeff's questions:

> Wood, brick, lath-n-plaster, construction?
> One floor, two floors, big windows, small windows?
> Totally flat or on a hillside? Basement? Attic?
> Online photo? Numbers? Details?

The building is over three floors, including the attic. Walls are of
brick construction and the windows are small, leaded lights.

A very rough plan can be seen here -
www.thejamfactory.eclipse.co.uk/plan.jpg

A picture can be seen here -
www.thejamfactory.eclipse.co.uk/photo.jpg

> Is the building floor plan squareish, or elongated? How far are the
> two key places at opposite ends of the house?

The distance from office A to office B is approx 25 meters

> I'll take your word for that, but I've found that buildings with
> outside plumbing are very easy to cable. I try to sell the owner on
> wiring the house for cable TV, telephone, bunglar alarm, thermostat,
> intercom, etc at the same time. See comp.dcom.wiring for hints.

There may be a straightforward route for some CAT5 caballing, if run
external to the property. There is already a PABX phone system which
runs between the rooms, so routing may be simpler than originally
thought.

I have considered Ethernet over mains, but as it is a very old house,
the wiring may be separate circuits and I'm certain of the quality.

> You've led a sheltered life. Welcome to wireless hell. The real
> secret to successful wireless is to get a clear line of sight. NLOS
> (non line of sight) solutions are at best a crap shoot. Shooting
> *THROUGH* a building or house is one of the best ways of guaranteeing
> repeat visits to "optimize" the wireless. You might be able to make
> it work today, but as things move around the house, the path will
> change. I strongly suggest you avoid shooting through a house. If
> you must do so, then place the access point at one end of the house,
> attach a fairly large panel antenna (14dBi gain 35degree beamwidth)
> and point it towards the other end of the house. If possible, shoot
> it down a hallway. Your level of success will be limited by the
> number of walls the signal has to smash through. I've found 3 to be
> about the limit. If the walls have aluminum foil backed insulation,
> give up now.

Thanks for this advice, it makes me even less likely to install a pure
wireless solution. The last thing I want to do is install a solution
which is unreliable and will require additional visits to troubleshoot.

> Run the wires if possible. Otherwise, try illuminating from the
> outside. Do NOT bother trying to shoot through the building unless
> your site survey shows a very strong signal or you have RF transparent
> inside (glass?) walls.

Thanks again for your advice, I'm investigating the structured
caballing option, with localized AP for individual areas.

On 29 Jun 2005 01:51:02 -0700, "Chrishow" <(E-Mail Removed)>
wrote:

>The building is over three floors, including the attic. Walls are of
>brick construction and the windows are small, leaded lights.
>
>A very rough plan can be seen here -
>www.thejamfactory.eclipse.co.uk/plan.jpg
>
>A picture can be seen here -
>www.thejamfactory.eclipse.co.uk/photo.jpg

Nice house.

I don't think a single wireless access point is going to work. 2.4GHz
does not like water or anything with water in it. Masonry, brick, and
vegetation are full of water to varying degrees. Same with asbestos
or crushed rock in the roofing tiles. 2.4Ghz is not going to
penetrate even one wall, much less the 3 or more required to do this
with a single access point. You're only chance is going through a
window, some of which appear to be clogged with vegetation.

You might have a chance if the interior construction is of light wood
(i.e. pine). 2.4Ghz will go though about 2 such walls. Watch out for
wallpaper with aluminum foil backing.

I scrounged for data on materials attenuation in the past and found:
http://www.thirdbreak.org/pipermail/...ne/000804.html
Note that the attenuation for brick varies from 2 to 8 dB depending
upon who did the testing. Apparently, there are some rather drastic
variations in test and construction techniques.

>The distance from office A to office B is approx 25 meters

Looking at the layout, my guess is that you'll be shooting through at
least 2 brick walls (not counting inside walls) no matter the
alignment. Your only chance is if you have a common pair of windows
where each office is directly visible from the other. That doesn't
appear to be the case.

>There may be a straightforward route for some CAT5 caballing, if run
>external to the property. There is already a PABX phone system which
>runs between the rooms, so routing may be simpler than originally
>thought.
>
>I have considered Ethernet over mains, but as it is a very old house,
>the wiring may be separate circuits and I'm certain of the quality.

I've had terrible luck with powerline networking. Too slow and
subject to interference from appliances. On of my friends did that
and found that his connection was comatose when running the laundry
machines.

If you have existing telephone cabling, it might be possible to use
them for ethernet connectivity. I've done this successfully with 25
pair cable at 10baseT (10Mbit/sec) rates. It will NOT work at
100Mbits/sec and all connections must be forced to use 10Mbits/sec.
The catch is that it MUST be dry, good quality, paired cable and is
probably limited to about 25 to 50 meters per run.

I've also done it using 10base2 (Cheapernet) over CATV coax cable.
http://www.multilet.com/us/baseband/...duct_range.htm
One run is about 300 meters or RG-6/u.

Topology is somewhat of a nightmare because it must be arranged as a
"star" rather than a "bus". That means all your phone cables and
wires have to come together at one location. That's possible in an
office building, but usually difficult in a home where the phone
wiring is arranged as a bus.

>Thanks for this advice, it makes me even less likely to install a pure
>wireless solution. The last thing I want to do is install a solution
>which is unreliable and will require additional visits to troubleshoot.

It is possible to use wireless through walls and obtain a reliable
system. However, I have some evidence to the contrary. Current, I'm
replacing wireless with wired in approximately 10% of my installations
due to reliability issues. I have an other wiring job to replace
wireless in 2 days. The problem is usually interference from other
wireless users. That may not be an issue here as it appears that
there are no neighbors. Working with desktops is always a problem
because they don't move. A laptop can move around if there are
changing propagation conditions (i.e. moving furniture). That's not
so easy with a desktop. I've found users constantly juggling the
position of their wireless devices to accommodate the latest changes.

A site survey, also known as "try it and see how it works" is fairly
simple. If you have a good solid strong signal throughout the
building, then it will work. If it varies all over the place, then it
probably will be a problem. A fun test is streaming media content
with a small buffer. If the music sounds intermittent and full of
dropouts, so will the data.

>Thanks again for your advice, I'm investigating the structured
>caballing option, with localized AP for individual areas.

That might work if the inside construction is light weight. Good
luck.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

On Wed, 29 Jun 2005 08:55:33 -0700, Jeff Liebermann
<(E-Mail Removed)> wrote:

>I've also done it using 10base2 (Cheapernet) over CATV coax cable.
> http://www.multilet.com/us/baseband/...duct_range.htm
>One run is about 300 meters or RG-6/u.

Wrong URL. I forgot you were in UK. The products are somewhat
different:
| http://www.multilet.com/en/index_eng.htm

There are others, but they are mostly for large apartment buildings
and OEM manufacturers:
| http://www.coaxsys.com
| http://www.mocalliance.org

I've also previous ranted on the subject of 10baseT over CATV cable:
| http://groups-beta.google.com/group/...cea2cea3c89c42


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Jeff,

Thanks for your assistance, you seem very knowledgeable in this area!
We are most likely going to run CAT5e to the areas which require
wireless access, then install AP's.

As you seem to have installed many sites, I was curious to find out
what Wireless AP hardware you normally use? I've used Buffalo kit in
these scenarios previously, but wondered what else is available on the
market, possibly the type of devices used in a more commercial
environments?

I see that Cisco kit appear at the top of the ladder when it comes to
commercial kit, but I wondered what manufacturers are in between and
worth considering?

On 7 Jul 2005 01:47:56 -0700, "Chrishow" <(E-Mail Removed)>
wrote:

>We are most likely going to run CAT5e to the areas which require
>wireless access, then install AP's.

Sounds like a workable plan.

>As you seem to have installed many sites, I was curious to find out
>what Wireless AP hardware you normally use? I've used Buffalo kit in
>these scenarios previously, but wondered what else is available on the
>market, possibly the type of devices used in a more commercial
>environments?

I haven't really done that many wireless installs. Most of what I do
is repair existing installs, engineer complex systems, do some design
work, play wireless consultant, and deal with WISP related issues. I
also help setup and play policeman for a few coffee shop style hot
spots. I rarely get to choose the hardware as it is already in place
by the time I get involved. I have no real preference as to brand or
model and tend to end up with mixed systems. Well, actually I do
prefer Cisco 350 series with separate routers, but my small customers
can't afford much of that.

In a classic example of do as I say, not as I do, our neighborhood
wired and wireless LAN consists of all the mixed junk that was
returned or rejected by my customers. The major specifications are
that it not have a fan that makes noise and that it be cheap (or
free).

>I see that Cisco kit appear at the top of the ladder when it comes to
>commercial kit, but I wondered what manufacturers are in between and
>worth considering?

For conventional business systems, look at Proxim Orinoco and
Sonicwall TZ170 series.
http://www.proxim.com/products/wifi/
http://www.sonicwall.com/products/tz170SP_wireless.html

For office buildings and distributed hot spots, look into wireless
switch vendors such as Aruba (HP), Airespace (Cisco), Trapeze (3com),
Chantry (Siemens), and Symbol:
http://www.arubanetworks.com
http://www.symbol.com/products/wireless/wireless.html
http://www.airespace.com
http://www.chantrynetworks.com
http://www.trapezenetworks.com
Methinks a centralized management and monitoring system is a basic
requirement for any complex or large system. I'm online right now
looking at erratic >70% packet error rates for one wireless access
point. Looking at the RRDTool history graphs over the last few days,
something new appeared on Tues afternoon. My guess(tm) is that
someone installed a cordless phone in the warehouse and planted the
base right next to the access point.

Wireless switches offer this type of central management. However, the
problem is that once committed to a wireless switch vendor, you're
also committed to a homogenous system consisting only of the vendors
proprietary hardware and solution. If they drop the ball, you end up
replacing everything. The central switch box also presents a single
point of failure so be prepared to deal with backup issues. Also,
some of the wireless switch vendors have blundered into the direction
of wireless mesh networks, which I consider an RF polluting
abomination and should be avoided if possible.

Of course, everything you buy today will be obsolete tomorrow, so plan
ahead somewhat. WiMax might also be a suitable solution when the
cheap hardware finally arrives.

Just talked to the customer with the >70% error rate. Nice new
Plantronics Bluetooth cordless phone adapter sitting literally on top
of the Cisco 340 wireless access point. Moved a few feet apart and
the error rate is down to about 5%. Try doing that without history,
statistics, and remote management.



--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558