Wireless access point range
Another strange problem (which started out quite normally)…
Customer has wireless “dropouts” and has difficulty maintaining a reliable internet connection. He also doesn’t have wireless security.
So I decide to setup WPA security, and then look into what dropout he has.
He also has a wireless repeater, so to avoid confusion, I switched it off while working on the router.
With a laptop right next to the netgear WAP + 4 port router, I easily setup WPA on the router and the laptop.
I then setup another laptop in an office (about 10 meters away), but get no signal…
I pickup the laptop and walk over to the main house where the WAP is located… as I enter the room, the laptop connects, and it is on the internet. Ah, good… I didn’t make a mistake with the setup.
So now I decide to look at the wireless repeater, as it looks like I’ll need it to get a signal to the office.
The way it works is: press the sync button when it is close to the WAP, and it will lock-in on the strongest wireless signal. Then connect it a little further away, and it will remember the last WAP it synchronised with, and it will basically extend the range on the WAP (acting like a go-between).
However, since I disabled the SSID broadcast on the WAP, the repeater won’t be able to synchronise (and it doesn’t know the keyphrase I used!)… so I need to connect to it via ethernet and manually enter the WAP details (like SSID and keyphrase). After that, it synchronises correctly.
I then setup the repeater 2 rooms away, and it cannot connect with the WAP… whats going on?
I set it up in the kitchen, but still no go.
I try a bookcase just 3 meters (and 2 walls) away from the WAP, and it finally syncs (at last!).
I then try a laptop, but no go 🙁
I am having some serious signal attenuation problems!
I switch off the repeater and concentrate on the WAP: as soon as I walk out the door with the laptop, the signal drops to half strength, and pings just stop.
At this stage I’m sure there must be something in the walls that are blocking the signal.
I cannot do much more, so I recommend that the customer abandons the wireless and goes with a wired solution.
On my way home, I start thinking that the problem could be with the WAP antenna. A frayed cable would give the same symptoms that I’ve been seeing (although I’ve never heard of a wireless antenna failing).
I arrange a second visit, where I will test the signal strength using another WAP that I know works well… Except he cancels the very next day, since he doesn’t want to deal with the wireless anymore… he will just go with a wired setup as I suggested. I also suggested he get a proper electrical contractor to install the wiring, as I don’t have the knowledge to do electrical kind of work (eg running wires within wall cavities, proper RJ45 wall outlets, etc).
I guess I won’t find out what the problem was, but I’ll remember to check the antenna, next time something like this happens.
I deal with radio a fair bit in my line of work, and yes a faulty antenna does seem logical. Incorrect impendance matching will result in a strong signal right next to it, but the radiation field will be small and as such any distance away from it will result in a severe signal drop.
Unlikely there is anything in the walls, unless they are concrete or lead lol. If it is 802.11g then it should penetrate concrete fairly well, well at least from room to room. 11a/b has a fairly small signal and can be attenuated quite easily.
But yeh, wired is probably the easiest for most people to go with, especially seeing the fact its safer for the day to day users. The amount of unsecured wireless connections these days is enormous, lucky there arnt to many people taking advantage of them i spose.
OK, I didn’t know if there was something in the walls that could stop the signal. It was 802.11G, and the walls were just plasterboard, with a brick wall between the corridor and the kitchen…
But since the signal started dissappearing before I even got to the brick wall, then I guess its safe to say it was an antenna problem.
I’ve wondered how “dangerous” an 802.11G signal is… I know that it has some output gain limits… so that its illegal to amplify. But I assumed that its just a low-power high frequency (almost microwave!) signal… I wouldn’t want the antenna next to my head, but a meter or two away should be safe?
802.11g operates on around 2.4ghz, same as 802.11b, alot of cordless televisions and microwave ovens. So yes, it is a microwave frequency (microwave can “generally” be defined as anything over 1ghz) but it does run on a very low power output.
When you talk about things like this people always say “I wouldnt want that to close etc etc” but most of us have cordless phones these days, how close to your head can you get..
Mobile phones, similair problems, especially with all the 3g and NextGen that we get. Its all microwave signals right next to our brains.
That said, yes its probably not to good for us, but we are continually exposed to signals like this these days, maybe we are killing ourselves. But who is going to give up there mobile phone now…
Back to the subject, walls wouldnt be a problem obviously, i operate my wireless over 2 floors of a house, in the backyard, no drops anywhere. Defiantly sounds like the aerial, or internally the router itself has got gain issues, maybe the automatic gain control circuit is fried etc. There are a range of issues, but if hes going to a wired connection then theres no need to worry.
Maybe if you ever have problems again a spare antenna from an old router could come in handy, play the old “switch components till it works again” trick. Still one of the best fault finding methods out there.