Help me hook a brother up!
September 10, 2010 10:22 AM Subscribe
Extending wireless networks: how can I connect a 802.11b/g network between sites a couple of hundred feet apart?
My bother-in-law is trying to connect his farm office computer to a new milking system in his barn, two or three hundred feet away. Data needs are not huge. The base system sends a few packets every second or so. However, if possible, he'd like to run a VOIP or skype phone over the connection too.
He's trying to avoid digging up his yard, as very heavy vehicles---tracked high hoes, combines---use it continuously and he's concerned that conduit would get quickly crushed. Trenching cost and time are also concerns.
This has to be point-to-point. There's no place in the yard (or power) to put a repeater.
So what are his options? Booster antennas? Some sort of dish system?
My bother-in-law is trying to connect his farm office computer to a new milking system in his barn, two or three hundred feet away. Data needs are not huge. The base system sends a few packets every second or so. However, if possible, he'd like to run a VOIP or skype phone over the connection too.
He's trying to avoid digging up his yard, as very heavy vehicles---tracked high hoes, combines---use it continuously and he's concerned that conduit would get quickly crushed. Trenching cost and time are also concerns.
This has to be point-to-point. There's no place in the yard (or power) to put a repeater.
So what are his options? Booster antennas? Some sort of dish system?
A diagram!
[computer]---[bridged router]---[outdoor antenna] . . . . . [outdoor antenna]---[normal router]---[cable/dsl modem]
And if you want to do what my neighbor and I did, where my wireless signal was used by the bridge and my computers, and he had his own separate wireless network on a different channel for his computers:
[his computer] . . . [his own wireless router]---[bridged router]---[outdoor antenna] . . . . . [outdoor antenna]---[normal router]---[cable/dsl modem]
posted by davejay at 10:35 AM on September 10, 2010
[computer]---[bridged router]---[outdoor antenna] . . . . . [outdoor antenna]---[normal router]---[cable/dsl modem]
And if you want to do what my neighbor and I did, where my wireless signal was used by the bridge and my computers, and he had his own separate wireless network on a different channel for his computers:
[his computer] . . . [his own wireless router]---[bridged router]---[outdoor antenna] . . . . . [outdoor antenna]---[normal router]---[cable/dsl modem]
posted by davejay at 10:35 AM on September 10, 2010
oh, and total outlay for mine was $50 per router, and I see outdoor antennas that are suitable for $50-$100 a pop at the local Frys
posted by davejay at 10:36 AM on September 10, 2010
posted by davejay at 10:36 AM on September 10, 2010
Response by poster: Yeah, we're just looking for internect connectivity back to the connection in the office. Your first diagram is what he wants.
I'm happy flashing firmware; I used Tomato on a WRT54G for years.
Searching for exterior antennas turns up a bunch, but I was wondering if anyone had any particular equipment recommendations or companies to stay away from. Links or brandnames I can search for would be a great help.
posted by bonehead at 10:51 AM on September 10, 2010
I'm happy flashing firmware; I used Tomato on a WRT54G for years.
Searching for exterior antennas turns up a bunch, but I was wondering if anyone had any particular equipment recommendations or companies to stay away from. Links or brandnames I can search for would be a great help.
posted by bonehead at 10:51 AM on September 10, 2010
Pringles cans. The power of Google compels you!
posted by Biru at 10:54 AM on September 10, 2010 [1 favorite]
posted by Biru at 10:54 AM on September 10, 2010 [1 favorite]
Yup. DaveJay's pretty much on the money.
You could also use WDS between the two routers, which would give you better wireless access in the barn (so the cows can use their iPads, etc.). Not all routers support it, but lots do, especially if you install a custom firmware. The WRT54GL and DD-WRT are a safe bet.
posted by schmod at 10:55 AM on September 10, 2010
You could also use WDS between the two routers, which would give you better wireless access in the barn (so the cows can use their iPads, etc.). Not all routers support it, but lots do, especially if you install a custom firmware. The WRT54GL and DD-WRT are a safe bet.
posted by schmod at 10:55 AM on September 10, 2010
I have done some long dx wifi before with varying results.
If you have line of sight between the barn and the office, it will help. When I did this last, I used an Engenius USB with a 15 db patch antenna. At the time, the building I was living in did not have any sort of WIFI hookup, so I was left to leeching off of free service from the local library that was a few hundred feet away. Wasn't the greatest, but it worked in a pinch. If I had better line of sight, I am sure that the connection would have been more than adequate. Basically I was getting a connection at a couple of hundred feet.
davejay's solution also sounds like a good way to go, just a bit more technical.
posted by lampshade at 10:58 AM on September 10, 2010
If you have line of sight between the barn and the office, it will help. When I did this last, I used an Engenius USB with a 15 db patch antenna. At the time, the building I was living in did not have any sort of WIFI hookup, so I was left to leeching off of free service from the local library that was a few hundred feet away. Wasn't the greatest, but it worked in a pinch. If I had better line of sight, I am sure that the connection would have been more than adequate. Basically I was getting a connection at a couple of hundred feet.
davejay's solution also sounds like a good way to go, just a bit more technical.
posted by lampshade at 10:58 AM on September 10, 2010
One last thing....I still use the Engenius adapter to this day and it still rocks. May be a bit out of date now, but it always manages to find all sorts of networks out there. I have however, graduated to paying for my own cable wifi now!
posted by lampshade at 11:00 AM on September 10, 2010
posted by lampshade at 11:00 AM on September 10, 2010
You'll need two directional antennas for this, like this trendnet. You'll also need to verify that the router you buy allows for external antennas and verify that you are using the same connectors. There's a few different antenna connectors. Most likely you'll need to buy a couple of adapters.
I'd also make sure that the router you buy can handle having both transmit and receive on the same antenna. I use DDWRT on a linksys and had to explicitly set it to use the proper antenna. The linksys WRT54GL is designed to handle DDWRT btw. There are few tutorials on the net, but the hard part will be mounting and placement. Ideally you want the cable from the antennas to the router to be as short as possible. The longer it is the worse your SNR.
In the world of DDWRT you'll be building a "Client Bridge."
[main router] wired connection- [ddrwrt linksys] >>>>>>wireless>>>>>>>>> [ddwrt linksys] wired connection [computer]
The DDWRT people have a busy forum, you might want to also ask there. Good luck.
posted by damn dirty ape at 11:21 AM on September 10, 2010
I'd also make sure that the router you buy can handle having both transmit and receive on the same antenna. I use DDWRT on a linksys and had to explicitly set it to use the proper antenna. The linksys WRT54GL is designed to handle DDWRT btw. There are few tutorials on the net, but the hard part will be mounting and placement. Ideally you want the cable from the antennas to the router to be as short as possible. The longer it is the worse your SNR.
In the world of DDWRT you'll be building a "Client Bridge."
[main router] wired connection- [ddrwrt linksys] >>>>>>wireless>>>>>>>>> [ddwrt linksys] wired connection [computer]
The DDWRT people have a busy forum, you might want to also ask there. Good luck.
posted by damn dirty ape at 11:21 AM on September 10, 2010
Seconding that outdoor directional antennas like the Trendnet damn dirty ape suggests are the way to go. Make sure you do one at each end; a rookie mistake is putting it on the originating router only, forgetting that wireless is a two-way connection.
posted by davejay at 11:23 AM on September 10, 2010
posted by davejay at 11:23 AM on September 10, 2010
pringles cans are cool and cheap and fun, and I'm not going to discourage you from experimenting with that first to save money, but make sure you've got the bridge working properly at close range with the EOM antennas first, so you don't spend hours aiming pringles cans when the problem is your config
posted by davejay at 11:24 AM on September 10, 2010
posted by davejay at 11:24 AM on September 10, 2010
Response by poster: Thanks for the software recommendations. That will be a great help.
Those trendnet antennas seem to be what I'm looking for. A gain of 15dB appears to be the magic number for a few hundred feet, right?
How far can a cable can I run from the antenna to the router? Is 20 ft going to be a problem?
Are there any concerns with metal roofs?
posted by bonehead at 11:43 AM on September 10, 2010
Those trendnet antennas seem to be what I'm looking for. A gain of 15dB appears to be the magic number for a few hundred feet, right?
How far can a cable can I run from the antenna to the router? Is 20 ft going to be a problem?
Are there any concerns with metal roofs?
posted by bonehead at 11:43 AM on September 10, 2010
we use this building to building bridge. Probably more expensive than the options mentioned above but works well
posted by canoehead at 11:43 AM on September 10, 2010
posted by canoehead at 11:43 AM on September 10, 2010
Two of these:
http://www.ubnt.com/nanobridge
They're $79 each for the 22dB version of $99 each for the 25dB version. At the distances you're talking about the $79 ones will be fine. They can be used to create a layer 2 Ethernet bridge across the distance you need. Likely they will connect at MCS12 or better (802.11n-2009 modulation) so it will be a line rate 100BaseTX bridge. Connect a second WAP or a LAN switch at the barn end.
posted by thewalrus at 12:01 PM on September 10, 2010
http://www.ubnt.com/nanobridge
They're $79 each for the 22dB version of $99 each for the 25dB version. At the distances you're talking about the $79 ones will be fine. They can be used to create a layer 2 Ethernet bridge across the distance you need. Likely they will connect at MCS12 or better (802.11n-2009 modulation) so it will be a line rate 100BaseTX bridge. Connect a second WAP or a LAN switch at the barn end.
posted by thewalrus at 12:01 PM on September 10, 2010
Are there any concerns with metal roofs?
Shouldn't. These things will be mounted so that they're not behind any obstruction. You'll really need to point them perfectly at each other. If that's too difficult, then you might be able to get away with one directional and one omnidirectional.
Is 20 ft going to be a problem?
20ft is fine with the proper cable. Trendnet sells a cable with the proper connector at the length.
A gain of 15dB appears to be the magic number for a few hundred feet, right?
We're assuming line of sight, right? If so, you could go with less, but why? You're not really saving money.
Also, you should be using a wifi network monitor that shows the SNR. Inssider does this and its free.
posted by damn dirty ape at 12:10 PM on September 10, 2010
Shouldn't. These things will be mounted so that they're not behind any obstruction. You'll really need to point them perfectly at each other. If that's too difficult, then you might be able to get away with one directional and one omnidirectional.
Is 20 ft going to be a problem?
20ft is fine with the proper cable. Trendnet sells a cable with the proper connector at the length.
A gain of 15dB appears to be the magic number for a few hundred feet, right?
We're assuming line of sight, right? If so, you could go with less, but why? You're not really saving money.
Also, you should be using a wifi network monitor that shows the SNR. Inssider does this and its free.
posted by damn dirty ape at 12:10 PM on September 10, 2010
I use this antenna for setting up a portable network. One warning I will give about high gain antennas, is the very little margin of error in the aiming. You need to be fairly precise when you mount the antennas. Once they are up and configured, the setup from damn dirty ape will work great.
posted by Climber at 12:44 PM on September 10, 2010
posted by Climber at 12:44 PM on September 10, 2010
Response by poster: damn dirty ape, sorry, just want to be certain that I don't underbuy something not good enough. Money-saving is seconday. I want to be certain that this will work.
We have a laser transit available. Is that enough for aiming? 18° of aiming angle seems acheivable.
Via thewalrus' manufacturer, I've found a local source for the Ubiquiti antennas, Xagyl Communications. They're about $86 for the 5m's. The Nanobridge looks seriously impressive. If I'm reading that install instructions correctly, I don't even need routers with that kit. They've got a built-in minirouter that's enought to setup the bridge. Slick.
posted by bonehead at 1:41 PM on September 10, 2010
We have a laser transit available. Is that enough for aiming? 18° of aiming angle seems acheivable.
Via thewalrus' manufacturer, I've found a local source for the Ubiquiti antennas, Xagyl Communications. They're about $86 for the 5m's. The Nanobridge looks seriously impressive. If I'm reading that install instructions correctly, I don't even need routers with that kit. They've got a built-in minirouter that's enought to setup the bridge. Slick.
posted by bonehead at 1:41 PM on September 10, 2010
This thread is closed to new comments.
First, I got hold of two Linksys WRT54G routers, the ones that run on Linux and are compatible with the Sveasoft firmware (not all of them are, so do your research.)
Then, I downloaded and installed the Sveasoft Alchemy firmware on both units (back when it was free; now there's a small fee to get it from them with tech support, or you can look around for people legally hosting the old files, since it's all open source) and configured one as a bridge.
A moment here to help you understand what this means: one router acts like a normal router, sending out a wireless signal that can be used by anyone with the proper authentication. The bridged router, on the other hand, acts like a wireless client, connecting to the signal from the first router like a computer would.
Now you can plug a computer into the bridged router, and it behaves as if you're plugged into a normal router, except the signal feeding the bridged router comes from the first router instead of your cable/DSL modem. You can even plug a third wireless router into the bridged router, if you're so inclined.
If you want to share files between computers on both sides of the bridge, you're going to have to jump through big hoops, but if you just want internet access this'll work a treat. Note that the Sveasoft firmware allows you to amp up the antenna transmit power significantly beyond the legal US levels, and the WRT54G has antennas you can replace with outdoor directional antennas to improve the distance the bridge can cover.
I used this method successfully to share an internet connection with a neighboring house; it wasn't a few hundred feet (more like 80-100), but it was through several plaster walls with no special antennas and no line of sight. With a few outdoor antennas (be sure to ground them!) and line of sight, a few hundred feet should be no problem.
posted by davejay at 10:32 AM on September 10, 2010