[plug] home cat5 issues

Paul Antoine pma-la at milleng.com.au
Tue Mar 25 14:55:38 WST 2008


Greg,

It certainly seems you could do with a directional antenna pointing down 
the hill from the front house to the back - either a parabolic or 
Pringles cantenna. A parabolic antenna such as the one on Altronic's 
website gives a broader spread which may suit you better for laptop use 
between the two houses.

Note also that antenna's are best kept as close as possible to the 
transmitter (router) as the cable is lossy and you can lose all the 
advantage of the higher gain antenna if the cable is too long. The 
2.4Ghz signals used in wi-fi are particularly prone to this... and of 
course the number of solid objects (e.g. walls) between router and pc. 
Many people use power over ethernet (PoE) so they can mount the router 
outside very near the antenna (in an IP67 weather/dust-proof box) and 
have a powersupply safely inside.

Before you commit to an antenna you could do a test where you place the 
current router on the outside wall of the front house that points at the 
back house.  Then test coverage both inside the front house and down the 
hill into the back house.

Here's a site with the Pringles description if you feel up to building one:

http://www.seattlewireless.net/index.cgi/PringlesCantenna

You can buy a manufactured version here:

http://www.cantenna.com/

I have wholesale access to Altronics and it shows the parabolic antenna 
is a good deal cheaper for me to buy.  Let me know off-list if you're 
interested.

Oh, and I have a spare Linksys WRT54G v2 router if you or anyone else on 
the list would like one (yes, I'd like some $$s for it, but I am 
reasonable :-) It runs DD-WRT and OpenWRT etc.

P.

Gregory Orange wrote:
> Craig Foster wrote:
>>> -----Original Message-----
>>> From: plug-bounces at plug.org.au [mailto:plug-bounces at plug.org.au] On
>>> Behalf Of Paul Antoine
>>> Sent: Thursday, 20 March 2008 5:39 PM
>>> To: plug at plug.org.au
>>> Subject: Re: [plug] home cat5 issues
>>>
>>> I'm a fan of larger antennae for poorly performing wireless links... I
>>> always try to buy an AP with replaceable antennae. Marvellous what a
>>> difference a 7dbi antenna can make!! (And no, more power on the AP
>>> doesn't help.)
>>>
>>> P.
>>
>> For cheap home sites,
>> http://www.freeantennas.com/projects/template2/index.html and a
>> (semi-)flattened pringles do two things:-
>> 1) kills the signal *behind* the AP meaning it doesn't extend equally
>> over next door :)
>> 2) directs the signal towards your other wireless AP and/or laptops.
>> Over two floors, don't forget to tilt the antennas :P
>>
>> 7dB antennas are at least $60 each, so it's not the cheapest option.
>>
>> IIRC Matt Kemner was a member of www.e3.com.au, so he should be a good
>> source of info should you want to do longer distance wireless.
> 
> Ah good, a source of experts. I suppose I should have asked here long 
> ago. Anyway, I've been vaguely asking around at computer and electronics 
> shops for ages, never got any confident advice so never did anything.
> 
> Fairly straightforward requirement: I'd like longer coverage from my AP. 
> It's a D-Link DI524 (from memory... I think that's right). Replacing its 
> regular-length antenna with a longer one (came with another wifi card 
> I've got) gave me small improvement but not nearly enough. I see 
> Altronics has:
> http://www.altronics.com.au/index.asp?area=item&id=S9719
> http://www.altronics.com.au/index.asp?area=item&id=S9722 (hmm, looks 
> like my longer one)
> http://www.altronics.com.au/index.asp?area=item&id=S9725
> http://www.altronics.com.au/index.asp?area=item&id=S9730
> http://www.altronics.com.au/index.asp?area=item&id=S9739 (yikes)
> 
> I'll attempt a description of the layout. Two houses on one property, 
> front and back. It slopes from the front house, fairly gently downhill 
> (where the AP lives) to the back. Currently I get zero coverage inside 
> the back house, and poor signal in between the two.
> 
> My question: Can someone advise me what to buy and who to buy from? I've 
> heard e3 might be a good place to go. The boards there aren't super 
> active so I thought I'd start here - especially while we're talking 
> about it (: I suppose e3 people might be active, just not using the boards.
> 
> Cheers,
> Greg.
> _______________________________________________
> PLUG discussion list: plug at plug.org.au
> http://www.plug.org.au/mailman/listinfo/plug
> Committee e-mail: committee at plug.linux.org.au



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