Watching The REIN As It Pours

I haven't posted for a while as there has been relatively little progress and even less news. To be honest, it gets a little depressing to have nothing but bad news to write about.

This time, although winter approaches and the wet and windy weather has done its utmost to drop broadband speeds across the village to an all-time low, there is good news, of a sort, to report. After almost 18 months of knowing the entire village suffered from repetitive electrical impulse noise (REIN) crashing broadband, today I finally managed to visualise it. Better still, I may have got the best lead yet on how the REIN is causing its effects. Its never really been certain whether the interference was carried on the power lines or on the telephone lines - but after today, I think its pretty clear.

A few weeks ago, I installed a power filter and conditioner to try and eliminate RF interference propagating through the mains supply. It can't prevent the losses of sync occurring after a REIN event, but it has resulted in a consistently better sync speed and bit-loading profile. It has even increased my average IP profile by around 15% - not a lot, but I'll take any extra bandwidth I can get.

If you read my 'other' blog "BT Broadband and How to Survive It," you will have seen that I recently acquired a new toy, a widget called Wi-Spy 2.4i - a spectrum analyser. If you want to read more about what it is, what it does and where to get it, take look here.

To put it simply, what it does is to look at the wireless spectrum used by the wifi side of your router and look for sources of interference that might be blocking particular wifi channels. All sorts of things can cause problems like this - microwave ovens, car alarms and immobilizers, PIR's, street lights and many of the other things that can cause REIN.

The weather was bad today with constant wind and rain - in other words a very likely to have a bout of our lunchtime REIN, which usually hits at around 1350, give or take a few minutes. Sure enough at 13:48 we got hit with REIN, the router resynced and the IP profile dropped from 1250kbps to 500kbps - much as it has done fairly regularly on weekdays for the last few months.

The surprise was that the Wi-Spy caught the REIN event - something the makers were adamant it wouldn't do; but there it is as plain as punch.

If you look at the screenshot above (click on it to enlarge), you will see the read-out from the Wi-Spy. There are two different displays. The lower one shows the current activity across the 2.4GHz wifi band. The hump in the middle is my router on channel 6, showing how channel 6 actually runs over into all channels between 4 and 8. In the upper display you can see two horizontal smears on the right hand side. These are my microwave oven running! The vertical line near channel 13 is my next door neighbour's car alarm - and a good reason to avoid channels 10-12.

The real surprise was the thick horizontal trace that begins when the REIN hits at 13:48. It runs right across the trace from below channel 1 to above channel 14 - the entire range of the 2.4GHz spectrum used by broadband wifi. It also appears to be strongest at the lower frequencies - suggesting, perhaps, just how massive the REIN signal is at frequencies below 2.4 GHz.

The second picture I've attached shows the router response at 13:48 - a complete loss of sync and subsequent drop in IP profile, sync speed and throughput speed.

13:48 is also the time one of my neighbours suffers from TV interference and loss of broadband sync.

So what, you may well ask, we've all known that REIN was the cause of the broadband problems for over a year. That's true enough, but given that ALL the power supplying my router, PC and other bits of kit is now heavily filtered and conditioned, the only other likely sources of the REIN is the phone line.

This is where things may start to get really interesting. Whilst OFCOM has not been overly helpful in respect of broadband issues, they do have a statutory duty to investigate sources of TV and radio interference and would also appear to have parallel legal remedies to enforce solutions. Our next course of action is fairly obvious.

Its also triggered another thought. I've always assumed that the REIN was directly affecting my router and the others in the village. But perhaps, if the signal is on the telephone line, its the DSLAM at the exchange that is being affected and not the routers, or perhaps both. More for OFCOM to ponder I suppose!