Wireless access point as extension?

[JohnR66]

I found out my city has free wireless. I can't receive it, so I built an antenna out of a soup can. This high gain directional antenna now can receive many signals in different directions I can point it. I can see the free signal now, but it is weak and flaky.

Since the antenna wire should not be very long due to attenuation, I would like to setup some sort of remote wireless receiver and use Ethernet to bring it back to my PC. Can anyone recommend a good reliable device?

Thanks, John

 

[Fallingwater]

I can't help specifically with the ethernet problem, but I might be able to help in another way. Cantennas (antennas made with cans) are simple to make and a damn sight better than the stock antennas that come with wifi devices, but they aren't really great.
If you really want an effective directional antenna, use a satellite dish meant for TV reception.
You can either put a USB transceiver in place of the stock receiver doodad, or you can go all the way and build a proper biquad antenna, which should work even better. Googling for "satellite dish wifi" will get you all the relevant information.

 

[binky]

The simple solution might be to use a really good grade COAX cable such as RG6 quad-shielded, or RG11. Then your attenuation should really not be too much of an issue. I use that to run a cell phone reception extender to an antenna in my attic and the loss is negligible.

However, since you've built yourself a can antenna, you probably already experimented with better feed coax, so here's the less simple and more expensive solution:

So, let me try to rephrase the desired topology... You've got the city signal that you can't receive very well. The soup can-tenna is doing the job well, but reception stinks from where your computer is. You have access to where the soup can gets good reception, maybe from the attic or roof or wherever better, but there's no power up there and you need power?

Do I have that right? One of the constraints is that there's no power but you need power where you can put this cantenna?

You can get a low-volt power source to do that.

You have a couple options for receiving the signal and getting it back to your place, but let me suggest the power solution -- use a Power Over Ethernet (POE) injector such as this one or any of a zillion others.

Now, about the reception. You could get a wireless router that supports being powered from POE and stick that up into your attic, then put the wireless cantenna or a non-homemade directional such as a nice yagi onto its antenna port. Here's one such POE access point. I didn't research whether its antenna can be unscrewed to put on a directional rather than the omni, but this might get you started.

If you can run an Ethernet cable from your computer to a place where the reception is good, then maybe the POE could solve the dilemma.

 

[JohnR66]

Power is not a problem for me. As I understand the 2.4GHz signal is lost quite a bit in cable due to such a high frequency. I would have to run 25 feet of cable which is far too long for that signal. I forget the number but power is halved with only a few feet of cable, so 25 feet would kill the signal.

I understand that many wireless access points can run in bridge mode, but I assume the AP on the other end has to be in bridge mode as well. What I need is an AP to act as a receiver so I can put it in the attic near the cantenna so I can make the long run in Ethernet.

 

[binky]

Okay. I finally get it. A very good question. I now finally understand what you want (sorry I'm so dense). Hehe.

You're talking about wanting your access point to behave just like the WiFi card in your PC, negotiating as a client node, from the attic. There are WDS, wireless distribution service, nodes, but that's not what you need and yes if it were one of those it does require negotiation set up at both ends. Bridge mode is different from WDS and doesn't require the other side (the city side, in your case) to be specially set up any different from any usual wireless router. Bridge mode will get the job done.

So, you can use bridge mode on a router if it supports it or just get a dedicated access point. The LinkSys WET54G can do what you need. Seems to have the typical unscrew-able antenna port you need. You can first configure it when plugged directly into the Ethernet port of your PC then if you want to extend your number of devices on the LAN plug it into your WAN port of your router if you have one, or leave it plugged into only your PC if you don't have other stuff to plug in.

 

[JohnR66]

Thanks for the reply. This morning I bough a Trendnet low cost AP. It does several modes including WDS, client and repeater modes.

Repeater mode is cool. It involves no Ethernet cable, it receives a signal and duplicates it on another channel. So I can put it up high in the house to get the remote link and it sends the signal down to the computers.

The only problem now is, with the addition of the AP and its signal, my computer and several AP in the neighborhood on the same channel, the signal is still flaky. Time for a dish like Fallingwater suggested.

Update: I got the "cantenna" mounted high up in the attic and it is working great now. I'm getting 600kbps up/down which is fine for free. I can use my computer or take my net book anywhere in the house and get 5/5 or 4/5 bars.