Ask Slashdot: Why Does Wireless Gear Degrade Over Time? 615
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?"
Signal isn't chaning, the noise floor is (Score:5, Insightful)
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 (Score:4, Insightful)
built in failure. bow to your corporate masters and go consume.
Did the signal degrade, or the noise increase? (Score:5, Insightful)
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.
analog transistors age (Score:5, Insightful)
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.
various causes (Score:2, Insightful)
The loss in performance could be due to the solder between components (mostly between the antenna and circuit board) is degrading overtime (this happen a lot with industrial devices), also the diferents components as capacitor and resistor could be wearing out too.
Re:Did the signal degrade, or the noise increase? (Score:5, Insightful)
Re:Did the signal degrade, or the noise increase? (Score:5, Insightful)
Yeah. Just change it to channel 2 and interfere with everyone using channels 1 and 6, BECAUSE THE ONLY NON-OVERLAPPING CHANNELS on 2.4 Ghz ARE 1, 6, and 11.
I'm not an electrical/radio engineer, but I could have designed a better standard...blindfolded.
To your question, here's the answer... (Score:2, Insightful)
It's by design. Especially if those devices are marketed for the American market. Wanna know what else is designed to fail after a certain set time?
Well, Microwave ovens, cars, especially those from one once big American car company, that recieved millions in bailout cash under this president.
In industry, it's called Planned Obsolescence [wikipedia.org], and Americans are pioneers.
Here's [go2gbo.com] a write-up about it.
Capitalism at its best!
Re:Did the signal degrade, or the noise increase? (Score:5, Insightful)
This used to work, but with the common availability of WiFi, any scan of your local neighborhood will often never find a channel with more than 1 channel separating you from neighbors (auto channel switching isn't aggressive enough...why is that?). The only way I've found to keep ahead of it is to invest in new frequencies as they become available. I've had the 5Ghz spectrum for quite a few years with no neighbors using it until this month. The first one popped up on my scanner a few weeks ago.
The other has to do with the quality of the equipment. I used to use Linksys, then Netgear, and then tried Buffalo as was disappointed with each either through hardware issues, or due to poor performance. The Linksys gear seemed to go down hill after Cisco bought them, but I always thought that Cisco was an industry leader (not in the telecom field so feel free to chime in). My old 10Mb switches are still working after a decade but it seems rare to find one of these that lasts this long these days.
I finally ended up with an Apple Time Machine which worked well with a mixed environment of Windows and Mac's for wireless backup, and my original printer didn't have WiFi so the print server was ideal. I have a WiFi printer now but that also works as well.
4 years later and I'm still pulling 16 MB/s (granted with very little competition on the 5Ghz band) with mixed mode (g for the printer, and some older smart phones that can't hit 5Ghz).
Holding out for the newest frequency, after which I'll switch again.
Re:Signal isn't chaning, the noise floor is (Score:5, Insightful)
Re:Did the signal degrade, or the noise increase? (Score:3, Insightful)
Don't get caught by the FCC, there are some pretty hefty fines for interrupting that reserved space in the spectrum.
Re:Signal isn't chaning, the noise floor is (Score:5, Insightful)
That wouldn't explain why replacing the router fixes the problem, unless he just happens to be replacing the old router with one that just happens to have a stronger transmitter or better antenna. The pessimist in me says that the chances of that happening can't be 100% of the time.
From my experience with all the major manufacturers of consumer routers and switches, the problem is capacitor quality primarily.
Transmission range and stability will suffer over time because of unstable or insufficient voltage.
Also these devices get really hot these days. Most if not all are passively cooled, and don't even have much real ventilation in their casings.
They're designed to be cheap, and to last for at least 12 months generally.
I've replaced all the capacitors on several Linksys "Business class" Gigabit switch, they all started failing after about 14 months.
I did this to my own switch about 4 years ago, and it's still going strong today. I've also done this on an old Linksys WRT54G.
Re:Re Jamming your neighbors (Score:4, Insightful)
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.
Re:Signal isn't chaning, the noise floor is (Score:5, Insightful)
FCC doesn't seem to care when people shit all over the bands used for WiFi in some random suburb. I'm going to guess they are more interested in fining radio DJs and filing paperwork for a million or so a year new consumer electronics devices.
Re:Cisco is an industry leader (Score:5, Insightful)
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.
Re:Signal isn't chaning, the noise floor is (Score:2, Insightful)
.
No "funny" mods, please, I'm dead serious.
Oh, and steal his wallet while he is under...
Re:Signal isn't chaning, the noise floor is (Score:5, Insightful)
There are 14 channels (frequencies) in 802.11b/g/n (2.4 GHz). There are only 3 that do not overlap though (1,6,11). The best thing to do if you plan to use the 2.4 GHz range is to run something like inSSIDer and see which of those 3 channels are least congested, then set your router to use that range. The problem with 2.4 is the lack of non-overlapping channels, and the fact that most routers have a default setting to pick the "least congested channel" but not conform to the 1,6,11 standard. So therefore you have all your neighbors congesting multiple channels by overlapping 1 and 6 or 6 and 11, using a channel in between. This is a nightmare for high-density areas (I do wireless for large conferences. It's a huge challenge).
In 802.11a/n (5 GHz), there are 23 channels you can use (depending on if you bond for N or not). This is like comparing a 3 lane highway to a 23 lane highway. Your density capacity is FAR higher than 2.4. The downside is that most mobile devices do not have 5 GHz radios, and 5 GHz, because of the nature of the higher frequency, does not penetrate (giggidy) as far as 2.4 (as you said). From a management point of view this is a benefit, but when you are trying to cover a large house it leads to weak signals at the edges of the house, if you center it. This is a good point to use multiple access points though (routers without the routing in lay terms).
So, the near future for wireless is 5 GHz (or, "Wireless A and N"). 5 GHz is catching on (iPhone 5 and a few Androids and Tablets have it now) and will start to get much busier, but the great thing about that is it's designed for it. The downside to the less-near future is that 802.11ac will add larger bonding in the 5 GHz range, which will lead to less available channels/capacity. We'll see how that goes...
One correction to your comment I have is that N is not 5 GHz specific, and it has not at all changed people from 2.4 to 5. It's only allowed more throughput than G or A did on those frequencies. It's caused more problems than not because of the fact it can use the 40 MHz window, taking up 1 of the 3 non-overlapping channels, pissing off your neighbors.