Building design & WiFi problem

I am trying to resolve a problem of WiFi coverage in a fairly
recently-built property in the UK. Coverage is poor in general and
there are several rooms that are total dead spots.

After much investigation, I've pinned it down to the building
construction. The key issue is that the internal walls and ceilings
have been constructed using metal-foil-backed plasterboard. Even the
insides of the exterior walls are finished with the same material.
Michael Farady would've been proud of the builder.

By way of confirmation, mobile phone signal levels are abysmal inside
the building, better very close to a window, and good and strong just
outside of it.

Multiple WiFi access points linked to a wired backbone is the
classical approach, but would not be welcomed by the customer.

- I've heard of wireless relays - anybody have experience of them?
- Any other suggestions for a solution?
- Ripping out the bacofoil is not an option :-)

On Sat, 18 Mar 2006 02:02:41 GMT, Frazer Jolly Goodfellow
<no-(E-Mail Removed)> wrote:

>I am trying to resolve a problem of WiFi coverage in a fairly
>recently-built property in the UK. Coverage is poor in general and
>there are several rooms that are total dead spots.
>
>After much investigation, I've pinned it down to the building
>construction. The key issue is that the internal walls and ceilings
>have been constructed using metal-foil-backed plasterboard. Even the
>insides of the exterior walls are finished with the same material.
>Michael Farady would've been proud of the builder.
>
>By way of confirmation, mobile phone signal levels are abysmal inside
>the building, better very close to a window, and good and strong just
>outside of it.

Our local University just built some energy efficient buildings, which
included aluminized mylar windows in addition to the metal foil backed
polyurathane insulation. No RF gets in or out.

>Multiple WiFi access points linked to a wired backbone is the
>classical approach, but would not be welcomed by the customer.

That's the arrangement that works best. Using the AC power line as a
backbone is possible, but doesn't work with more than a few carrier
devices as everyone is sharing the same wires.

>- I've heard of wireless relays - anybody have experience of them?

Yes. They're called "range extenders", "repeaters", "store and
forward repeaters", and "range expanders". Mesh networks are a form
of such repeaters. The only advantage is that it can use wireless
instead of a wired connection for a backhaul. The downsides are:
1. They don't scale well.
2. Maximum bandwidth is cut in half through each repeater.
3. Standards are not in place for repeaters. Compatibility issues
are epidemic.
4. If you setup your building with one SSID for the whole building,
each repeater will repeat ALL the traffic, from every access point,
resulting in considerable excessive wireless traffic. Also, repeaters
are not too good about distinguishing traffic from other repeaters and
tend to generate traffic exponentially.
5. If the client can hear both the access point and the repeater,
traffic will slow down by more than half the maximum thruput.

For a while, I was ripping out repeaters and installing wired access
points.

>- Any other suggestions for a solution?

1. Run the wires.
2. Use the HVAC ducts as waveguide. I did this at a hospital to
avoid wiring and politics. It sorta worked.
3. Piggy back on the phone wiring. I've run 10baseT-HDX over 25 pair
telco wire for about 300ft without issues. The catch is that you'll
only get about 5 mbits/sec thruput.
4. If you have coax cables in the wall for CATV, that can be used for
10base2 networking at 10baseT-HDX. Same issue with speed.

visitors.... gone.

>- Ripping out the bacofoil is not an option :-)

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 (E-Mail Removed)
# http://802.11junk.com (E-Mail Removed)
# http://www.LearnByDestroying.com AE6KS

Can you do wifi over radiax?
Jeff Liebermann wrote:
> On Sat, 18 Mar 2006 02:02:41 GMT, Frazer Jolly Goodfellow
> <no-(E-Mail Removed)> wrote:
>
> >I am trying to resolve a problem of WiFi coverage in a fairly
> >recently-built property in the UK. Coverage is poor in general and
> >there are several rooms that are total dead spots.
> >
> >After much investigation, I've pinned it down to the building
> >construction. The key issue is that the internal walls and ceilings
> >have been constructed using metal-foil-backed plasterboard. Even the
> >insides of the exterior walls are finished with the same material.
> >Michael Farady would've been proud of the builder.
> >
> >By way of confirmation, mobile phone signal levels are abysmal inside
> >the building, better very close to a window, and good and strong just
> >outside of it.
>
> Our local University just built some energy efficient buildings, which
> included aluminized mylar windows in addition to the metal foil backed
> polyurathane insulation. No RF gets in or out.
>
> >Multiple WiFi access points linked to a wired backbone is the
> >classical approach, but would not be welcomed by the customer.
>
> That's the arrangement that works best. Using the AC power line as a
> backbone is possible, but doesn't work with more than a few carrier
> devices as everyone is sharing the same wires.
>
> >- I've heard of wireless relays - anybody have experience of them?
>
> Yes. They're called "range extenders", "repeaters", "store and
> forward repeaters", and "range expanders". Mesh networks are a form
> of such repeaters. The only advantage is that it can use wireless
> instead of a wired connection for a backhaul. The downsides are:
> 1. They don't scale well.
> 2. Maximum bandwidth is cut in half through each repeater.
> 3. Standards are not in place for repeaters. Compatibility issues
> are epidemic.
> 4. If you setup your building with one SSID for the whole building,
> each repeater will repeat ALL the traffic, from every access point,
> resulting in considerable excessive wireless traffic. Also, repeaters
> are not too good about distinguishing traffic from other repeaters and
> tend to generate traffic exponentially.
> 5. If the client can hear both the access point and the repeater,
> traffic will slow down by more than half the maximum thruput.
>
> For a while, I was ripping out repeaters and installing wired access
> points.
>
> >- Any other suggestions for a solution?
>
> 1. Run the wires.
> 2. Use the HVAC ducts as waveguide. I did this at a hospital to
> avoid wiring and politics. It sorta worked.
> 3. Piggy back on the phone wiring. I've run 10baseT-HDX over 25 pair
> telco wire for about 300ft without issues. The catch is that you'll
> only get about 5 mbits/sec thruput.
> 4. If you have coax cables in the wall for CATV, that can be used for
> 10base2 networking at 10baseT-HDX. Same issue with speed.
>
> visitors.... gone.
>
> >- Ripping out the bacofoil is not an option :-)
>
> --
> # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
> # 831-336-2558 (E-Mail Removed)
> # http://802.11junk.com (E-Mail Removed)
> # http://www.LearnByDestroying.com AE6KS

> 2. Use the HVAC ducts as waveguide. I did this at a hospital to
> avoid wiring and politics. It sorta worked.

We almost universally don't have that sort of heating in the UK so that
wouldn't be an option.

I just think that it's about time that house builders would get with the
concept of either

a) floodwiring with at least cat5 during construction
b) install suitable trunking/ducting to allow cables to be pulled

These days we still have to tolerate some numpty builder sticking in one
TV aerial feed to the corner of a lounge and maybe an upstairs bedroom
and if you're lucky a couple of phone points. It's pathetic.

So far, i've only viewed one new housing development where the rooms
were wired and brought to a central hub although the amount of money
they added on for this was just stupid such that I'd still have opted
out and done it myself.

David.

(E-Mail Removed) hath wroth:

>Can you do wifi over radiax?

Yep. But it's not just Wi-Fi that's the problem. Even broadcast FM
and TV doesn't work inside the building. A leaky coax (Radiax) system
that will work with all forms of RF is both technically and
financially challenging. The problem was known when the building was
designed and the solution selected by a committee that placed "RF
exposure" as the primary criteria for a successful system. The
building has internal CATV coax, fiber, CAT6, and empty conduit to
take care of most connections. There are wireless access points all
over the place. However, for cellular, they went with micro-cellular
technology from NextG to limit "irradiation".
http://its.ucsc.edu/services/telepho...verage_map.pdf
http://currents.ucsc.edu/04-05/07-12/antennas.html
http://www.nextgnetworks.net/univers...santacruz.html
It barely works.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

The better developers in the US have :structured wiring" upgrades or
just toss it in.

Maybe its me, but I never looked at wifi as a home networking solution.


David Taylor wrote:
> > 2. Use the HVAC ducts as waveguide. I did this at a hospital to
> > avoid wiring and politics. It sorta worked.
>
> We almost universally don't have that sort of heating in the UK so that
> wouldn't be an option.
>
> I just think that it's about time that house builders would get with the
> concept of either
>
> a) floodwiring with at least cat5 during construction
> b) install suitable trunking/ducting to allow cables to be pulled
>
> These days we still have to tolerate some numpty builder sticking in one
> TV aerial feed to the corner of a lounge and maybe an upstairs bedroom
> and if you're lucky a couple of phone points. It's pathetic.
>
> So far, i've only viewed one new housing development where the rooms
> were wired and brought to a central hub although the amount of money
> they added on for this was just stupid such that I'd still have opted
> out and done it myself.
>
> David.

David Taylor <(E-Mail Removed)> hath wroth:

>> 2. Use the HVAC ducts as waveguide. I did this at a hospital to
>> avoid wiring and politics. It sorta worked.
>
>We almost universally don't have that sort of heating in the UK so that
>wouldn't be an option.
>
>I just think that it's about time that house builders would get with the
>concept of either
>
>a) floodwiring with at least cat5 during construction
>b) install suitable trunking/ducting to allow cables to be pulled

That's too easy. I often am asked "what kinda wiring do I bury in the
walls to insure connectivity?" My usual answer is conduit, not wire.
Nobody seems to listen and I get all kinds of abominations for my
trouble. One remodel ended up with CAT5 run as a "daisy chain"
instead of a star (home run). That's fine for telco, but useless for
networking. Another was told to have everything come to one place.
The electrician interpreted that as everything coming to near the
power meter which was outside. So, I now have a 10/100baseT switch in
an outdoor box hanging on the side of the house. Still another did a
fair job of wiring the basement, first floor, and loft, but neglected
to install any means of connections between floors. Yet another
installed CAT5 in the walls, and used a staple gun rather clumsily so
that half the wires were shorted and the other half were cut.
Fortunately, a majority of the remodels and new houses I've been
involved with have been very satisfactory.

Perfect timing. It's Saturday and the phone rings. It's a friend
doing a networking install in a very expensive brand new home. Claims
the house is "internet ready" whatever that means. No conduit and the
only wire in the walls are one run RG-59/u coax (yech) and two pair
telco station wire (CAT zero). It seems they forgot to install
something.

>These days we still have to tolerate some numpty builder sticking in one
>TV aerial feed to the corner of a lounge and maybe an upstairs bedroom
>and if you're lucky a couple of phone points. It's pathetic.

Agreed. I've had substantial arguements with electricians, who
usually end up doing the datacomm wiring on remodels and new houses,
over how to do the datacomm wiring. Since the job is always on a
fixed bid basis, they consider this "extra work". Getting it in the
original plans is not difficult, but datacomm always seems to be an
afterthought. Ever look at any of the "ready to build" home plans you
can buy on the internet? None of them have any manner of datacomm
wiring or conduit.

I don't expect standards as the technology changes far too rapidly. 15
years ago, we would be running fat yellow RG-8/u coax for ethernet.
Then came RG-58a/u for 10base2. Then came CAT3 for 10baseT-HDX. Then
came CAT5 for 100baseT and Gigabit ethernet. Throw in a dozen
different flavors of fiber connectors. At lease RG-6/u is fairly
common, but the routing of satellite and CATV are quite different. It
is possible to buy cable bundles with a few of everything included,
but these are expensive and almost impossible to repair.
http://www.smarthome.com/8682.html

>So far, i've only viewed one new housing development where the rooms
>were wired and brought to a central hub although the amount of money
>they added on for this was just stupid such that I'd still have opted
>out and done it myself.

I've also seen only one new development that made the effort. They
ran ENT (flexible non-metallic conduit) and let the buyers electrician
do the rest. Unfortunately, they ran everything together in the
ceiling above a closet, so wiring and installing network hardware was
a bit of a challenge. Office building usually do it much better.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann <(E-Mail Removed)> wrote in
news:(E-Mail Removed):

> On Sat, 18 Mar 2006 02:02:41 GMT, Frazer Jolly Goodfellow
> <no-(E-Mail Removed)> wrote:
>
>>I am trying to resolve a problem of WiFi coverage in a fairly
>>recently-built property in the UK. Coverage is poor in general
>>and there are several rooms that are total dead spots.
>>
>>After much investigation, I've pinned it down to the building
>>construction. The key issue is that the internal walls and
>>ceilings have been constructed using metal-foil-backed
>>plasterboard. Even the insides of the exterior walls are
>>finished with the same material. Michael Farady would've been
>>proud of the builder.
>>
>>By way of confirmation, mobile phone signal levels are abysmal
>>inside the building, better very close to a window, and good and
>>strong just outside of it.
>
> Our local University just built some energy efficient buildings,
> which included aluminized mylar windows in addition to the metal
> foil backed polyurathane insulation. No RF gets in or out.
>
>>Multiple WiFi access points linked to a wired backbone is the
>>classical approach, but would not be welcomed by the customer.
>
> That's the arrangement that works best. Using the AC power line
> as a backbone is possible, but doesn't work with more than a few
> carrier devices as everyone is sharing the same wires.
>
>>- I've heard of wireless relays - anybody have experience of
>>them?
>
> Yes. They're called "range extenders", "repeaters", "store and
> forward repeaters", and "range expanders". Mesh networks are a
> form of such repeaters. The only advantage is that it can use
> wireless instead of a wired connection for a backhaul. The
> downsides are: 1. They don't scale well.
> 2. Maximum bandwidth is cut in half through each repeater.
> 3. Standards are not in place for repeaters. Compatibility
> issues are epidemic.
> 4. If you setup your building with one SSID for the whole
> building, each repeater will repeat ALL the traffic, from every
> access point, resulting in considerable excessive wireless
> traffic. Also, repeaters are not too good about distinguishing
> traffic from other repeaters and tend to generate traffic
> exponentially. 5. If the client can hear both the access point
> and the repeater, traffic will slow down by more than half the
> maximum thruput.
>
> For a while, I was ripping out repeaters and installing wired
> access points.
>
>>- Any other suggestions for a solution?
>
> 1. Run the wires.
> 2. Use the HVAC ducts as waveguide. I did this at a hospital
> to avoid wiring and politics. It sorta worked.
> 3. Piggy back on the phone wiring. I've run 10baseT-HDX over
> 25 pair telco wire for about 300ft without issues. The catch is
> that you'll only get about 5 mbits/sec thruput.
> 4. If you have coax cables in the wall for CATV, that can be
> used for 10base2 networking at 10baseT-HDX. Same issue with
> speed.
>
> visitors.... gone.
>
>>- Ripping out the bacofoil is not an option :-)
>

Thanks everyone for the responses. No easy solutions (there never
are!) but at least I have a better understanding of the options and
issues.

(E-Mail Removed) wrote in
news:(E-Mail Removed) oups.com:

> The better developers in the US have :structured wiring"
> upgrades or just toss it in.
>
> Maybe its me, but I never looked at wifi as a home networking
> solution.
>

WiFi is a widely used solution here in the UK for retrofitting to
existing premises. As others have commented, structured wiring or any
other networking is virtually unknown in domestic buildings, unless
the purchaser pushes for it.

(E-Mail Removed) wrote:
> The better developers in the US have :structured wiring" upgrades or
> just toss it in.
>
> Maybe its me, but I never looked at wifi as a home networking solution.
>


Yes it is just you probable.... Can you not top post anymore? It is
really annoying for all of us!