Why would wireless wobble?
in [UK Mac]
|
Prev: White MacBook case
Next: iPhone lost itunes content
From: John Hill on 15 Dec 2009 03:32 About six months ago I installed a wireless ADSL modem at the behest of my ISP, who were unwilling to investigate my abysmal broadband speed unless I used their modem. It worked perfectly satisfactorily until last Saturday, when the transfer rate dropped to almost nothing. On Sunday I lost connection and could not restore it. In the evening it came back of its own accord, and since then it has been as normal. My wife has an ethernet connection to the same modem and her broadband speed has not been affected. What can cause a wireless connection to splutter in this way? Nothing IN the house has been changed. Could it be interference from some other wireless connection in the neighbourhood? Or interference from some other source? And if it happens again, is there anything I can do about it? For the record, if I <option>click the Airport icon in the menu bar, it tells me that it is using Channel 11 (2.4 GHz) and the Transmit Rate is 54 (whatever that means). John. -- Please reply to john at yclept dot wanadoo dot co dot uk.
From: T i m on 15 Dec 2009 04:39 On Tue, 15 Dec 2009 08:32:36 +0000, nemo(a)erewhon.invalid (John Hill) wrote: >My wife has an ethernet connection to the same modem and her broadband >speed has not been affected. If it's to the same box we are talking router here then really? > >What can cause a wireless connection to splutter in this way? Nothing IN >the house has been changed. Could it be interference from some other >wireless connection in the neighbourhood? Yes. > Or interference from some >other source? Yes, microwaves, car / house alarms, TV 'senders', remote 'HiFi' speakers, other radio stuff that's either near, loud or on a harmonic etc. > >And if it happens again, is there anything I can do about it? Sometimes, although that may involve an Ethernet cable or Ethernet _over_mains or other WiFi solution (802.11n). > >For the record, if I <option>click the Airport icon in the menu bar, it >tells me that it is using Channel 11 (2.4 GHz) and the Transmit Rate is >54 (whatever that means). The WiFi radio band is broken up into a rage of 'channels', just like many commercial radio / TV broadcasts or Radio Control models etc. The basic range on frequencies in the UK are allocated 1 to 13 for easy use (and not the same range in all countries) and the ideal solution is to be on your own unique frequency for your local hood and better a few channels away from anyone else. Many routers never get changed from default and so certain channels often become over-used, like 1, 6, 11 etc. The way to try to improve your own situation (it could change at any time of course) is to download a WiFi sniffer, possibly: http://www.macstumbler.com/ then turn your router off and run the sniffer to show you all the channels that are being used locally. Pick one that is the lest used (or unused) or if there isn't a completely spare slot, one with the lowest signal strength (suggesting it's further away) and ideally a couple away from any other channel. Then you connect to your router (look for your default gateway I/P address in your WiFi info when it's connected) and set your WiFi channel to your chosen one. Even if there isn't a completely free one avoiding the common ones or simply just changing the channel to something else may help. For now. The transmit rate you mention is the std speed (Mbps) for the 802.11g standard (and suggests you have a reasonable actual connection between your Mac and your router. Cheers, T i m
From: Jaimie Vandenbergh on 15 Dec 2009 05:40 On Tue, 15 Dec 2009 08:32:36 +0000, nemo(a)erewhon.invalid (John Hill) wrote: >What can cause a wireless connection to splutter in this way? Nothing IN >the house has been changed. Could it be interference from some other >wireless connection in the neighbourhood? Or interference from some >other source? Yes to both - it will almost certainly be an environmental effect. Possibly a neighbour got a new wifi box (probably an extended range one with strong signal) and set it to channel 11 also, swamping yours. Then later tried another channel, since you'd be interfering with them too. 802.11g isn't much good at dealing with that - 802.11n is better, but it'll still be perturbed. Microwaves and no doubt heavier equipment can molest a wifi signal too, but it's unlikely a neighbour had their microwave (or portable electric furnace...) on all day. If it's gone back to normal, don't worry about it too much. Cheers - Jaimie -- Some people have years of experience. Some have one year's experience several times.
From: John Hill on 15 Dec 2009 12:06 Jaimie Vandenbergh <jaimie(a)sometimes.sessile.org> wrote: > On Tue, 15 Dec 2009 08:32:36 +0000, nemo(a)erewhon.invalid (John Hill) > wrote: > > >What can cause a wireless connection to splutter in this way? Nothing IN > >the house has been changed. Could it be interference from some other > >wireless connection in the neighbourhood? Or interference from some > >other source? > > Yes to both - it will almost certainly be an environmental effect. > > Possibly a neighbour got a new wifi box (probably an extended range > one with strong signal) and set it to channel 11 also, swamping yours. > Then later tried another channel, since you'd be interfering with them > too. 802.11g isn't much good at dealing with that - 802.11n is better, > but it'll still be perturbed. > > Microwaves and no doubt heavier equipment can molest a wifi signal > too, but it's unlikely a neighbour had their microwave (or portable > electric furnace...) on all day. > > If it's gone back to normal, don't worry about it too much. > > Cheers - Jaimie Thanks to you and Tim for this helpful advice. I have downloaded MacStumbler, but at the moment all is well and "If it ain't broke, don't fix it". So I will hold it, and your messages, in reserve until the problem resurfaces. John. -- Please reply to john at yclept dot wanadoo dot co dot uk.
From: John Hill on 15 Dec 2009 12:15
John Hill <nemo(a)erewhon.invalid> wrote: > Jaimie Vandenbergh <jaimie(a)sometimes.sessile.org> wrote: > > > On Tue, 15 Dec 2009 08:32:36 +0000, nemo(a)erewhon.invalid (John Hill) > > wrote: > > > > >What can cause a wireless connection to splutter in this way? Nothing IN > > >the house has been changed. Could it be interference from some other > > >wireless connection in the neighbourhood? Or interference from some > > >other source? > > > > Yes to both - it will almost certainly be an environmental effect. > > > > Possibly a neighbour got a new wifi box (probably an extended range > > one with strong signal) and set it to channel 11 also, swamping yours. > > Then later tried another channel, since you'd be interfering with them > > too. 802.11g isn't much good at dealing with that - 802.11n is better, > > but it'll still be perturbed. > > > > Microwaves and no doubt heavier equipment can molest a wifi signal > > too, but it's unlikely a neighbour had their microwave (or portable > > electric furnace...) on all day. > > > > If it's gone back to normal, don't worry about it too much. > > > > Cheers - Jaimie > > Thanks to you and Tim for this helpful advice. I have downloaded > MacStumbler, but at the moment all is well and "If it ain't broke, don't > fix it". So I will hold it, and your messages, in reserve until the > problem resurfaces. > > John. As a quick follow-up, I see that my WiFi includes under Channel an "Automatic" setting, which claims to use the best available. Would it be a wise move to select this? John. -- Please reply to john at yclept dot wanadoo dot co dot uk. |