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Ask Slashdot: Why Does Wireless Gear Degrade Over Time?
acer123 writes "Lately I have replaced several home wireless routers because the signal strength has been found to be degraded. These devices, when new (2+ years ago) would cover an entire house. Over the years, the strength seems to decrease to a point where it might only cover one or two rooms. Of the three that I have replaced for friends, I have not found a common brand, age, etc. It just seems that after time, the signal strength decreases. I know that routers are cheap and easy to replace but I'm curious what actually causes this. I would have assumed that the components would either work or not work; we would either have a full signal or have no signal. I am not an electrical engineer and I can't find the answer online so I'm reaching out to you. Can someone explain how a transmitter can slowly go bad?"
and worn out. Also I think they have pretty short life spans.
As all of your neighbors add wireless routers, the noise floor goes up, and the usable signal goes down, even though the signal strength is the same.
built in failure. bow to your corporate masters and go consume.
Over 3 years I'd imagine a greater density of wifi devices all sharing the same spectrum to have appeared. Perhaps the signal level is the same, but the noise floor has increased substantially, degrading performance.
It could be the noise floor going up near your house, or just planned obsolescence.
..have a tendency to degrade and fail over time.
Obviously the magic smoke, although not released suddenly, does gradually leech out of the components leading to loss of performance over time.
"I bless every day that I continue to live, for every day is pure profit."
This is a hypothesis based on peripheral involvement with analog and digital RF at 0.5 and 1.5 GHz for twenty years.
AFAIK, the output stage of anything broadcasting above about 2 GHz has to be analog, with the lower frequency signal mixed into a carrier at the higher frequency. Digital synthesizers and chips which can deal with 1.5 GHz directly are still very expensive and are unlikely to be used in the consumer routers. So the final output stage is likely an analog RF transistor.
Analog transistors change characteristics with age at elevated temperature, where elevated is anything over 20C. Implanted ions diffuse with time and temperature, changing junction characteristics. The small structures required by high frequencies are more sensitive to such things.
Check the power supply. Usually the electrolytic capacitors are already dry.
Not sure about wireless gear, but some devices (e.g. printers, light bulbs, fridges) are designed to break after a certain period of time, so that you would buy a new one.
Using the same channel does not increase signal interference. Signal interference comes from APs using neighboring channels in close proximity. If you're looking for greater range, try switching to the same channel as your neighbor. Your bandwidth could be lower, but the interference will be reduced.
I've been using wifi instead of ethernet for about 7 years now. Almost all of the NICs/APs I've used have displayed this problem with time. It's as if the equipment somehow develops creeping signal attenuation. My guess is that it's something relating to capacitors gathering a slow overcharge of some sort, causing them to block current in a growing fashion - I seem to recall this being possible from my early days of electronics studies.
Anyhoo, I fix the problem by simply switching the equipment to another channel, say, 3-4 steps away, to make sure the frequency some of the components will be switching at will be notably different. So far it has worked with all equipment I've had this problem show up on. After a while the signal attenuation develops on the new channel as well, upon which I simply switch back to the one I used before. Rinse, repeat.
In my experience power adaptor degradation is the main culprit. Over time the adaptor will provide lower voltages and a less stable current. This translates into a lower signal output and higher noise respectably. I've seen bad adaptor turn repeaters into signal jammers - trust me, that was not an easy issue to troubleshoot...
1. slow burnout of emitter gear due to thermal degradation (yes, clock chips and transistors get hot, as do solder tracks and joints). Thermal runaway can occur if a solder joint fails and arcs, or overvoltage causes signal tracks to vapourise.
2. ionising radiation, particularly on unshielded components such as antenna conductors (I've seen something like this occur on an externally mounted amateur radio antenna: the sunward side of the antenna completely degraded, the result being that the only signals received (or sent) were on the shadow side).
3. component quality on consumer gear is not as stringent as it could be. Components can and do fail, and considering the number of components in a lot of consumer gear, it's a wonder any of it actually leaves the factory.
4. the noise floor of several years ago was far, far lower than it is now. The ERP of newer gear is (by design or by necessity) higher than older gear as more and more transmitters have to share the band. As a result, the signal quality taking a dive may be at least partly illusory. The equipment may actually be perfectly fine.
5. parasitic structures in semiconductor packages may be the catalyst for failure, either immediate or delayed. Such structures may be as small as a single atom of chlorine embedded in a crystal of germanium - innocuous at first (undetectable, even), but over time and use, that contamination will alter the chemistry of the semiconductor, possibly causing it to bond with the package material and rendering it useless. This might not even be an issue in high powered gear like regulators but in something like a microprocessor, it's a showstopper.
Operation Guillotine is in effect.
You are probably on to something here.
I volunteered at Free Geek, a computer recycler / refurbisher, years ago when "fat caps" on the motherboard was a frequent reason for computers to be sent there. AIR, the problem was a lot of counterfit components being sold to reputable manufacturers. There were several big name manufacturers involved. Something like that could be happening in the router market. Going with the lowest bidder for the components is still important in low margin markets.
Another possibility is that a kid in the neighborhood is collecting the innards of smoke detectors as part of his unofficial science project, and is storing them too close to your house. A radioactive environment will shorten the life of capacitors and other components. Have you noticed whether any of your kids glow in the dark?
I'm kidding with that last, of course. Sort of.
Will
Perhaps it's frequency drift. As components age their values change slightly. And when dealing with 2.4 Ghz and above tolerances are strict. It's just my guess.. Take it or leave it.
Like, oh, say, "smart meters".
When they started installing "smart meters" in my area because "too many" people were installing solar, and PGE were paniced that they'd have to pay the same rate they were charging instead of cutting off the payout at net zero by having differential rates so they payed less when solar was active, my bandwidth went to hell, and I had to more centrally locate my AP to avoid the interference.
Too stupid? Actually most people aren't 'stupid', it's just that most of the population don't live and breathe IT issues. An equally narrow-minded, self-absorbed mom in a typical household would also think you're stupid because you can't cook as well as she can.
When you grow up and leave your parent's basement, here's a tip -- try to be more diplomatic and really try to understand society as a whole. Not everyone knows what you do and conversely you're not stupid because you don't have the various skill-sets of everyone around you. Some day soon you'll be out in the job market and when that happens you won't score points in any job interview by stating how everyone else is stupid because you know something like how to change channels on your wireless router and they don't.
Monster Cables(tm) are much better for carrying electric audio signals, because they are outrageously expensive.
You need to buy cans of Monster Air to spray around your house.
You can find the product on their web site, and you really will be able to hear the difference on your wireless connections.
Probably.
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
"Bingo, I would wager that most households use wireless only now, since wireless only devices are becoming so popular. I just bought a house...not one inch of ethernet in the place. I don't know about you guys...but that would drive me crazy to make all my desktops wireless!"
Same here. My house was built in the 1950s. Guess they used mostly wifi back then, too.
Some idiot thought it was cheaper to spend $1 less on caps than the cost for customers calling tech support repeatedly for flakey performance.
A lot of tech companies have bean counters in charge, except they don't even know much about beans.
“Common sense is not so common.” — Voltaire
Six years ago, I took some tupperware cereal containers, drilled two holes in the bottom and pushed a WRT54G router's twin antennae through each hole. I caulked both holes. I inverted the containers, took an old broom stick and jammed it up into the contaners and screwed each router up high outdoors on buildings spaced 400' apart. I configured all three routers with DD-WRT in bridged/AP mode. I have never taken them down. This is in Vermont. They work great and cover some 18 acres. What more can I say?
*** Don't be dull.***
Having worked on some of the 802.11 algorithms, I can safely predict that all equipment with a crystal oscillator will eventually degrade.
802.11g was speced for a differential frequency deviation of 40ppm. Nominally thats 20 ppm allocated to AP and 20 to the remote.
In an effort to cut costs as much as possible (because most of you shop only on price, right?), the crystals used do not have good aging properties. It's not unusual to see crystals used that have as much as a 5-10ppm/yr agiing spec.
Unluckly customers will see their AP and remote device diverge, and within 3-4 years the frequencies are out of range of the algorithm's ability to compensate.
It's an exploit of a loophole in /. moderation. Funny mods provide no 'karma'. The basic idea is mod the post up funny, and back down overrated. This can repeat without end with enough moderators, and the poster goes to full negative karma for just one post.
Almost all cheap and even some expensive router's are built to fail. Cheap components and no cooling end up causing weak BGA joints and dryedup cap's causing it to fail. It the same with new TV's they last a few years then they die because of bad caps or overheated voltage regulators. look at old tv's they go forever. well until the tube burns out. I have a old console TV still works.