Calling Wi Fi Guru's - Advice?

[Kitsune]

Originally Posted by classicman

FWIW - the microwave at my parents eats their phone signal completely.

Same used to happen to me on the old 900MHz spread spectrum cordless.

Our new, overpowered, microwave eats the WiFi, here, completely. I need to change the channel on the router in the hopes that it might give it a bit more robustness, but I think we're out of luck for the most part. My old Powerbook completely loses connection, while Choco's Macbook Pro somehow survives it, barely.

[steambender]

like TW said, 802.11 Wi-Fi runs at the same frequency as your home microwave. The earliest versions are designed to co-exist with it, as most microwaves pulse at 60Hz, half cycle, so 50% of the time they're off, and the network would use those intervals.

I don't know if 802.11g, etc sticks to that, or maybe new, stronger microwaves changed to full wave...I've also never compared the legal leakage levels allowed for microwaves to the typical minimum required wi-fi receive levels, I should, it might be interesting to know how much interference to expect.

As far as propagation, absorption and shielding...Wi-Fi wants to go in a straight line...it'll bounce off metal if you need to make a bank shot, but unobstructed line of sight is what you want, and never get. That's why antennas work better high up, just as already suggested - better line of sight.

...Wi-fi wavelengths are about 4", so they'll sneak through gaps in metal that are bigger than an inch or so. they'll get blocked by metal ducts, foil backed insulation or low e glass windows (often have a transparent metallic coating to reduce solar load). they should go around small pipes and wires. They get absorbed by concrete, ceramic tile, wood and drywall. they fade with distance faster than lower frequencies, all in all, pretty tender stuff.

my linksys wireless access point has two antennas on swivels. It uses diversity reception techniques by exploiting the fact that two independent paths will experience different scattering as they bounce around the house, and so one of the two should arrive in better shape...it's very effective for time varying impairments like people walking around. yes, your body. a big conductive sponge to Wi-Fi.

Sometimes it helps to make sure that the two linksys antennas are pointed at right angles (one vertical, one horizontal, or both at 45 degrees). signal path scattering is also polarization dependent, and the little rabbit ears are polarized linearly with their orientation. that diversity trick, again.

if the access point is at the end of the house in the basement(?) and the access point antennas are removable, for a few bucks you could try a directional antenna aimed at the rest of the house...why waste signal in a direction you're not using?

whatever you do, don't forget your tinfoil hat. double ply is best!

[steambender]

I also heard a neat trick for getting networking and audio wiring installed in an existing house...central vacuum installers are expert at cheaply installing 1 1/4 (?) inch hoses in your walls, which are then dandy for snaking wires through...

[tw]

Originally Posted by Kitsune

Our new, overpowered, microwave eats the WiFi, here, completely. I need to change the channel on the router in the hopes that it might give it a bit more robustness, but I think we're out of luck for the most part.

Changing channels will not help. For all those Wifi channels, in reality, they overlap. Basically is only three separate channels - both ends and the center channel 6. They are all 2.4 Ghz. They share the same frequencies with many cordless phones, and other electronics - which also answers classicman's post.

Even XM working in lower 1.x Ghz frequencies can suffer interference if the antenna is located within 5 feet of the oven.

802.11a uses a different frequency from most other appliances (except some cordless phones). 802.11n should be more robust making interference less problematic. Netgear Rangemax was recommended previously due to its greater number of antenna configurations. Three more possibilities.

However in most every house, running an ethernet wire to another location is made so easy (but laborious) using things like the open space that goes from basement to attic alongside the chimney, those open back electrical boxes sold in Lowes and Home Depot, and, well, its amazing the number of tricks that alarm, telephone, vacuum, cable, intercom, and electric installers all have. Any can run provide holes for wires quickly. Running wires through walls is easy which is why I think poorly even of running exposes wires inside closets - another solution that makes running wires even easier. Difficult part is figuring where the drill bit will come out the other side. Thrill is when the drill bit emerges.

And then we have this miracle compound - spackle.

[Kitsune]

Originally Posted by tw

Basically is only three separate channels - both ends and the center channel 6.

Ah, that sucks. I thought we'd had better luck on another channel, but it was really more due to the previous underpowered oven.

Running wires isn't an option for us in an apartment, so we're simply going to have to continue to time the reheating of dinner to not interrupt cellar posts/network gaming/etc, etc.

[classicman]

Originally Posted by tw

Changing channels will not help. For all those Wifi channels, in reality, they overlap. Basically is only three separate channels - both ends and the center channel 6. They are all 2.4 Ghz. They share the same frequencies with many cordless phones, and other electronics - which also answers classicman's post.

Please answer it again - My parents are looking to get new phones.

Originally Posted by tw

And then we have this miracle compound - spackle.

LOL - spackle is your friend

[steambender]

Classicman...

microwave ovens operate at 2.54 GHz, same as Wi-Fi and some home cordless phones. There are other choices of frequencies for cordless phones, I saw some 5.8 GHz ones at Costco last week. They are far enough away in frequency that they shouldn't be interfered with by the microwave. There are also the old standby 900 MHz phones, which came out before the 2.54 GHz ones.

Each time a new frequency band is made available, and the chip companies make cheap silicon to support, people are conned into the new "better" frequencies. But all the sexy features don't matter if you get stepped on by another transmitter, deliberate or not.

[classicman]

So the microwave is operating at the 2.54 GHz - no doubt there? The problem is obviously on when the microwave is on. Therefore, if they buy a 5.8 GHz phone there will be no issue?

[glatt]

Originally Posted by steambender

There are also the old standby 900 MHz phones, which came out before the 2.54 GHz ones.

Our old 900 MHz analog Panasonic phone is dying. One of the buttons is getting sticky and isn't working right. We bought a new one, I think in the 5.8 range, digital (maybe even spread spectrum?), and the reception was FAR worse than the old one, so we returned it. There was static within the same room as the base station. Direct line of sight. Is there anywhere you can get these old 900MHz phones? I haven't seen any in stores. I'd love to just be able to buy a new matching handset. I love this old phone.

[Clodfobble]

Fry's has one online. It's advertised as for old people though.

with large easy to read buttons, a large red flashing call indicator, Caller ID, and an extra loud ringer, this phone is great for those loved ones that are hard of hearing.

[glatt]

Old people, eh?

It is analog, which is what our current one is. The thing just works.

[steambender]

yeah, microwave ovens are 2.54 GHz, but they're also unstable, sloppy, dirty and huge from a radio perspective. They're great at heating food. sort of like trying to have a conversation next to a jackhammer.

I can't give you any specific advice about which phones work better, a lot of it depends on the choices made by the phone designers (and the accountants). The name brands do usually try to avoid embarassing themselves.
even though I do this kind of thing for a living, when it comes to consumer stuff, I'm trolling the reviews on amazon and epinions, just like everyone else. I usually wait for 6 months or so before jumping to a new technology or until I read that something really kicks ass, or I can't control my geek urge.

glatt, the 5.8 GHz phones not working in the same room sounds really wrong..were they a reputable brand? (2.4 GHz spread spectrum panasonic in our house, but we are not frequent phone users, so don't encounter much interference). Ebay might be your best friend for finding replacement 900 MHz phones...Digital might work a bit better than analog, properly done it works a lot better.

Don't put all of the blame on the phones. over time, microwaves get their doors slammed a lot, and the RF shield gaskets may loose their coverage so that the oven leaks a bit more. The safety standards are pretty convervative, so there's little exposure risk (as life risks go) unless your teenager decides to turn the oven inside out in an effort to make a death ray and zap the neighbors cat. But the increased leakage levels will play havoc with other users of the same frequency band (Wi-Fi, cordless phones, wireless video cameras, RC control links, etc)

there are cheap ($30) microwave leakage detectors on the internet, but I have no idea how reliable they are. I personally use stuff like that at work, but we spend a lot of money on it, and it still takes experience to acheive professional results (that I'm willing to bet my paycheck on, anyway)

[glatt]

Originally Posted by steambender

glatt, the 5.8 GHz phones not working in the same room sounds really wrong..were they a reputable brand?

They worked, but when you walked around in the room, and turned and stuff, there was occasional static. Unacceptable, as our current 900 MHz analog phone works just fine. We can even go outside in the back yard with it, around 100 feet away. I wish I remembered the brand. I think it was Uniden, but not sure. Bought at Staples.

None of this is an emergency because we have a corded phone on each floor, but it's frustrating when the "new and improved" technology isn't as good as what it is replacing.

[aimeecc]

We had to move the wireless router and cordless phone base from the bedroom office to the 1st floor exercise room (which is directly below the bedroom office). We can now get both signals from anywhere in the house. Not sure why, but it worked. I think the cordless is 900 MHz, and I bought it maybe 3 years ago.

[tw]

Originally Posted by steambender

Each time a new frequency band is made available, and the chip companies make cheap silicon to support, people are conned into the new "better" frequencies.

The FCC (due to limitations by a more important group – ITU – because international standards are more important than domestic ones) has provided only some narrow frequencies for general, low power, unlicensed operation. These frequencies are called ISM (if I remember correctly: Industrial, Science, & Medical). For example the 900 Mhz is something like 918 Mhz plus/minus maybe 10 Mhz. Other frequencies are 433 Mhz, 5.8Ghz, 24 Ghz, and now 60 Ghz. 60 Ghz has recently taken interest in the movie industry where range is limited (apparently) because oxygen absorbs the signal; therefore preferred for wireless operations where one does not want remote monitors recording those signals. Manufacturers are only just starting to design commercial silicon for 60 Ghz - once only the domain of the military.

Some higher frequencies are also approved for ISM use - but the hardware is not yet available. It is not new frequencies made available. Limitation is getting hardware to work at those 'state of the art' frequencies. Reason for 'hyping' these new frequencies are so many appliances already using those lower frequencies. For example, add Blue Tooth to the list of 2.4 Ghz users. No wonder the 5 Ghz portable phone is now preferred.

Many of these ISM frequencies are not standard throughout the world. Wifi 2.4 Ghz is standard on the first (so called) eleven channels. Whereas the US allows ISM for 11 channels, I believe the Japanese (overlapping) version is a wider band (14 channels). BTW its 2.45; not 2.54 Ghz. 900 Mhz is available only in limited regions such as North America and a few other nations.

How to get your enemy to waste $1million. Setup a microwave oven so that it operates with the door open. Microwave ovens output massive power as to appear to Hellfire missiles as a radar site. One only loses a microwave oven. But the enemy wastes a $1million missile trashing that oven. Welcome to the Balkans.