802.11G health issue and home network cabling question

Hi dear all:

Recently after reading some articles I have some concerns about 802.11G WLAN health issue:

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Is Wifi or WLAN verified to have some health issues with humans? We have a baby (13 months) at home so we really don't want to take any risk.

Because of this, I'm thinking of giving up our current wireless LAN and use fixed line instead. However, although I'm a family handyman, but I have never did category-5 home wiring project before. I don't want to drill a hole on the wall only to find out that there is a water pipe behind the wall!!! So, is this some kind of project that I could do myself or I better hire a professional electrian or handyman to do the job?? Is there any online resources or advices that people could give me about this kind of home project? Many thanks!

Reply to
T. T.
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T. T. wrote

Nope.

Then you had better not have any kids.

It usually isnt that hard to work out where there is no possibility of any pipe, because there is nothing that uses water anywhere near there and to check that with a stud/pipe/wiring detector before you drill.

Yes, it aint rocket science.

They do manage to drill into water pipes.

Yep, plenty.

Reply to
Rod Speed

Your cell phone is designed to throw the signal hundreds of times farther and you hold it right to your ear, right? So no, no worries there.

Not necessarily because of that but cabling has lots of other benefits that still justify the need for it. You cannot power a device over wireless, just to give an example. Read

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more pointers.

They make stud finders for that. Don't you have one already?

It could be real fun and as an added bonus you will learn a lot about your house (leaks, rots, wasps ? you name it ;-)) doing it. So, yes go for it!

Sorry for the shameless plug but we carry a lot of useful info, including an e-book on the matter (link in my signature). You are welcome!

Reply to
Dmitri(Cabling-Design.com

Poke a small in the dry wall or drill a small hole very slowly without much pressure on the drill...go in about 3/4 of an inch and use a coat hanger to fish around for anything on the back side. And of course, get a decent stud finder and an energized wire detector.

Reply to
decaturtxcowboy

"T. T." hath wroth:

Concern and demonstrable proof are quite different. At the power levels of a typical Wi-Fi system, I would say that you and the baby are safe.

Let's pretend that there is an effect. According to inverse square law, the exposure is proportional to the square of the distance. Double the distance, 1/4th the exposure. 4 times the distance, and

1/16th the exposure. That means keep your distance and you're much safer.

However, you're not built in only 2 dimensions. RF absorption (as opposed to exposure) is proportional to the cube of the distance. Double the distance and you absorb 1/8th the RF. 4 times the distance, and you absorb 1/64th the energy. This is roughly how the SAR (specific absorption rate) is calculated for cell phones.

After distance, the next most important parameters are power and duty cycle. Power is easy. If the transmitter is on the air all the time, it's 100% duty cycle and you get the maximum absorption. However, if your transmitter is a GSM cell phone, it only transmits 1/8th the time. Therefore, you only get 1/8th the exposure. Wi-Fi varies in duty cycle. With no traffic, the duty cycle is something like 1/100th where all that gets transmitted are the beacon frames. Download furiously and it approaches 100% duty cycle.

Now, let's warp some numbers. The sun cranks out 1000 watts of energy per square meter at noon. The average wireless access point transmits about 15 milliwatts (0.015 watts) of RF. At a distance of 1 meter, that's a fabulous 15 milliwatts per square meter exposure. Therefore the sun delivers 66,666 times more power than your wireless access point. Sure, it's at different frequencies, but if the tin foil hat crowd can ignore frequency effects, then so can I. Like I said, "warp some numbers".

The Canadian university president declared that some unreferenced Calif PUC study said "more research is necessary". Well, yes... more research is always necessary. That's how researchers get their grant funding. There's no end to research and every research paper I've ever read has ended in "more research is necessary".

Anyway, enough numbers and educational politics. If you're seriously worried about RF exposure and don't want to take any chances, then running CAT5 is the obvious alternative. Just ignore the RF coming from TV, AM, FM, cellular, military, radar, aviation, and commercial wireless systems. Depending on your location, such RF levels can easily exceed your Wi-Fi levels.

Let's do some more math. How far would an FM broadcast station need to be away from your house to have the same RF exposure levels as your Wi-Fi at a distance of 1 meter. Well, the math is simple enough: Power_1 / Power_2 = Distance_1 ^2 / Distance_2 ^2 0.015 watts / 50,000 watts (ERP) = 1 meter^2 / Distance_2 ^2 Distance_2 = 1800 meters So, if you have an FM broadcast station within about a mile, it's producing about the same RF exposure level as your wireless access point at 1 meter. Actually the FM station is producing quite a bit more because it runs at 100% duty cycle while Wi-Fi averages much less, but I'll use worst case just like all the alarmist reports.

So, what can you do to reduce RF exposure? Aluminum foil wall paper is available. Frequency selective wallpaper can be found: |

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can turn your house into an RF screen room with RF absorbent non-reflective material. Actually, that might not be a bad idea if the kid turn out to be a chronic screamer.

Another easy fix is to simply turn off the transmitter when it's not being used. Carbon filled tubing slipped over the antenna works nicely. If you get a separate wireless access point and router, then you can just unplug the wireless part when it's not being used.

Verified by the FCC, NIH, or a peer reviewed medical publication? To the best of my limited knowledge, no such study has been verified. The problem is that most of the studies are epidemiological, where the research report attempt to correlate medical abnormalities with RF exposure. Since this takes a long time, the sample grouping is never differentiated by a single factor, and the preponderance of a multitude of other contributory factors, the chances of an epidemiological study finding something interesting *AND* repeatable, is zilch.

Read what I wrote in terms of the baby. Distance is the most important factor. That means what you feed the kid and his immediate environment is most important. Worry about those and not environmental issues that fade rapidly with distance. There's also more than a hint that growing up requires early exposure to bugs, filth, chemicals, and toxins to build up a survivable immunity. That which doesn't kill the kid make him/her stronger.

It's not that difficult but does take some practice. Since you have a kid, you should plan to redecorate or move things around about every 5 years. Might as well get used to running and terminating wires.

Drill a small hole in the wall and shove a coat hanger in to see what you're getting too close to. There are field detectors and toners for locating AC wiring (that's not in conduit). You can hear water pipes with a stethoscope. If you have money, you can get a fiber optic inspection viewer. Lots of ways to sniff around inside a wall.

Incidentally, you biggest problem will not be hitting a wire or pipe. It will be hitting a stud or firebreak with the drill. Unlike hanging pictures on the wall, you want to avoid the studs when running CAT5. Use a stud finder.

Your lack of imagination suggests limited abilities to do this right the first time. Perhaps having an electrician show you how to do it would be better than Learn by Destroying(tm).

Yes. Google found a few. Lots of vendors have tutorials under their "structured wiring" products. Dmitri has his site. You should be able to find something.

Reply to
Jeff Liebermann

No. The power output from the typical wireles router is so low that to really suffer any harm from your WiFi setup, you'd have to stick the antenna in your ear.

Reply to
Hackworth

Hi, Rod What is your credential to answer his question so well?

Reply to
Tony Hwang

You could always staple the wiring to the baseboards. (Locate an Ethernet router at some central point, to cut down wire length.) Or arrange all your computing devices in some central location (the "computer room"). I have a suspended ceiling in my basement, and drilling a hole in a closet gave me a way to get wiring up to my "computer room".

This posting suggests using the attic crawl space, and descend to meet a hole located in the wall. My house has no such space, so I cannot do this. But I do have a finished basement with an ugly ceiling.

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Try search terms like "pulling cat5 wire residential" in Google and see what pops up.

Another option is to do networking over the existing AC wiring. I don't know what the incidental radiation level is for this technology, but it might be better than wireless devices. Since the AC in North American homes is wired with two 110V phases, you may need a bridging device (capacitive coupling?) between the two phases at some point, to pass the signal from one phase to another. Otherwise, the Homeplug signal might have to go out to the pole transformer, before it can turn around and get to the other phase in your house. I don't know anything about this technology, and this is just a suggestion as something to research if you decide to go this way.

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Paul

Reply to
Paul

Since we are talking about category cables one should be extremely careful with stapling anything. General rule of thumb is that the cable should be able to move somewhat after it's installed. This way you can ensure the jacket is not cinched and the pairs inside are not damaged. It hard to achieve that with staples, even with rounded ones. Also, flat staples are absolutely no-no because they permanently damage the cable by flattening it out and jamming pairs into each other. Only rounded staples that match the cable diameter should be used. Still, avoid even those if you can.

Reply to
Dmitri(Cabling-Design.com

Tony Hwang wrote

Physically built my own house and have enough of a clue to realise that water pipes arent randomly placed in walls, they are only where there is a need for a water pipe.

Same with power too.

Reply to
Rod Speed

You want nice looking wall ports, and that can be a stinker to install. They need to be attached to studs, and that can mean cutting out a fair piece of sheet rock, and then repairing that. Also, it is not easy to go sideways in a wall. Talk to some pros, and get a price.

johns

Reply to
johns

Agreed about going sideways.. Up and over or down and under is a better bet..

There are a number of cut-in type mounting rings for datacom that work quite well, and do not require attachment to a stud. Caddy makes them, as does Carlon. You cut a hole of the right size, stick in the mounting ring, pull the wire thru, terminate the wire, and mount the plate.

Reply to
Bob Vaughan

Is your cellphone switched on?=20 Is there cellular coverage in your area? Do you use a Microwave Oven? Do you have a CRT TV or PC Monitor? Do you have electricity in your house?

BETTER TURN THEM ALL OFF QUICK - The radiation can cause brain tumors=20 etc.

It's all scaremongering bullshit.

--=20 Conor

I'm really a nice guy. If I had friends, they would tell you.

Earn commission on online purchases, =A32.50 just for signing up:

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Reply to
Conor

No they dont.

Nope, not if you use a stud finder.

No need if you do it properly.

You dont need to do that.

No thanks.

Reply to
Rod Speed

I think you are over-reacting.

Before giving up WiFi, you should give up uWave ovens and cellphones.

uWave ovens are not thought to be dangerous if they work correctly; if the door interlock fails, allowing the uWave to transmit when the door is open, then the danger from that ~1000W radiator is huge. And, don't put the cat in the nuker, unless you have a good fur stir fry recipe.

Cellphones are typically far more dangerous than PCs with WiFi, because radiated power decreases with the square of distance. You hold a cellphone with the antenna ~1 inch from your brain, while the antenna in a laptop is likely to be ~18 inches from your brain, and therefore ~~1% of the danger of the cellphone.

Reply to
Bob Willard

Nonsense...dropping a jack into a wall is pretty simple, at least for those of us that do it all the time. Unless you have a horizontal cross brace and then you'll need a Diversabit.

As Bob mentioned in his response, Caddy makes a low voltage rated (telecom and data use) metal back plate. Haven't seen anything like that at Lowes, but Home Depot carries the Leviton bracket. They also carry an orange plastic boxless bracket (compared to a full box electrical outlet box) in a ten-pack, but that seems overkill.

BTW, a nice way to firmly mount those metal brackets is to take an 8" pair of water pump pliers and squeeze the wings or tabs against the drywall (in addition to a drywall screw)...that way the faceplate doesn't wiggle around.

Tool Tip...Rinse off your drywall saw and drill bits or anything else that has drywall dust on it with a bit of WD-40. The dust is very hydroscopic and attracts moisture which will rust out your tools.

Reply to
decaturtxcowboy

Dmitri is so right! Customer did his own "cleanup" and stapled his CAT5 cable with an Arrow T-25 staple gun. I went back and did a cable test and it wouldn't even pass CAT3 10 Mbps. Her didn't short out any pairs, just crushed them to the point there were too many impedance bumps.

Lowes carries a new staple gun designed for network cables and coax with special plastic insert staples.

Velcro® is your friend....

Reply to
decaturtxcowboy

You guys are worse than me. I'm already running from this.

johns

Reply to
johns

| Physically built my own house and have enough of a clue | to realise that water pipes arent randomly placed in walls, | they are only where there is a need for a water pipe. | | Same with power too.

Whether _you_ might need it or not, the National Electrical Code used in the USA does specify a minimum of outlets distributed around. You can expect to find wiring pretty much on any wall wider than 2 feet.

Reply to
phil-news-nospam

google "old work box"; Electricians have been using them for years. There's no reason the box needs to be attached to a stud. For low-voltage wiring there are trim rings designed to be self-mounting in the wall.

Jerry

Reply to
Jerry Peters

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