There comes a time in a homeowners life when he realizes the importance of being able to play full high-definition content from his neighbor’s house 5 doors down… wirelessly.

Never mind the fact that getting the needed 20mbit sustained wireless connection for HD inside of a single house is difficult. The prospect of playing Music, DVDs and even full resolution HDTV between houses is just too tempting.

This is our story.

(vote for this story on digg or netscape)

Background
A few months ago, two SnapStreamians (Jason, Beyond TV lead developer and Zack, Beyond TV QA/your author) entered the glorious world of home ownership, 6 houses away from each other. The seed was planted early in passing conversation: “What if the houses were linked together?” The idea was tempting, but more pressing concerns, like garage door openers and lawn care, took precedence.

Time passed and most of the important projects were completed. Then, one day as we strolled the aisles of Fry’s (a surprisingly common occurrence), we wandered past the wireless networking section. “Extend your range 1.5 miles!â€? shouted one box. Could it be true? How fast would it be? We only need to go a few hundred feet. What would it take? Well, it was time to find out.

The research
Sadly, the Internet failed us in finding a great end-to-end guide of how to accomplish this task. We ran across a number of antennas and access points, but nothing really stood out as a nice package, short of some very expensive business class equipment. (If you have a good link to something that covers this, please post it in the comments.)

So we set the simple goal of allowing the two networks to speak to each other (no specific speed requirement) and took a guess about the hardware. We started with just the Buffalo wireless ethernet converter and a single 9db antenna. Aiming the antenna out the window of the 2 story house pointed to the attic of the 1 story, we achieved a connection to the standard access point in the house. Victory was ours! Except the connection speed was only 700Kbit/s. This would have been great, except our internet fiber connection to the houses was already faster.
So it began. A three week long process involving:

• 3 antennas
• 5 mounting points
• 4 access points
• so many trips to the roof and Lowe’s that we lost count

All of these things, culminating in a house to house wireless HDTV bridge.

A note to the un-initiated
In SnapStream tech support, we strongly discourage the use of standard 802.11g as a method of connecting Beyond TV Link to a server with HD content. The bitrate of HD is so high, it rarely works smoothly. Given that, our goal was generically pretty ridiculous, but that didn’t stop us.

Choosing the antenna
While the initial setup of pointing an antenna at other house’s regular wifi router worked, it proved that we actually needed specific hardware on each end if we expected to get anything faster than snail mail.

Clearly, the antennas were going to play a big part in the solution.
We tested 3 types

• A 9db directional outdoor
• 14db “corner” style (Omni-directional antenna in a 90 degree triangle box)
• 14db directional outdoor panel

The “corner” style antenna proved basically useless. The 9db directional was rather good, but maxed out at around 26% signal strength as reported by a WRT-54g with dd-wrt firmware. Good, but not good enough. That left us at the 14db directional antenna listed above. It achieved a 40% signal strength at a full 54mbps. This antenna was past the threshold of speed we needed for sustained HD and as a bonus, included all of the hardware we needed to mount it, short of a mast.

Antenna Placement and Mounting

For best performance, line of site between the antennas seemed desirable. Given easy access to the attic, we chose a pair of the 2.5″ sewer/drain vent pipes that extended from our roofs, both of which were at the rear most of the houses and had basic line of site to each other. Because of the size of the antennas, we needed to extend upward a bit from the pipe. We chose a 4′ piece of angle iron and used a dremel to cut it in half. Then, we spray painted it and two 3″ hose clamps flat black. Using the hardware included with the antenna, we mounted it to the iron and then attached the mast to the vent pipe with the hose clamps. For your installation, you may need to be slightly creative in your mounting solution. Just look for a good aiming position and figure out what it will take to mount the hardware.

Aiming
We started with the line of site directional aiming, each antenna pointed directly at the other. We maxed out at around 17mbps using this method. Our guess was that we were clipping the signal on some of the other houses. To remedy this, we aimed the antennas slightly out (see diagram). The theory here is that the radio waves are unobstructed as the leave the roof and then grow enough to hit the other antenna on the far side. Using this method, we achieved 22mbps sustained and bursts to 28mbps. Every installation is going to be different in this regard. The most important takeaway from this, however, is that in an obstructed view scenario, you may be physically limited from receiving a super fast signal.

Choosing the router and wireless ethernet converter
Once the antennas were mounted, most of the testing of this project was done with a Linksys wrt-54g with custom firmware on one end and the Buffalo Wireless Ethernet Converter (BWEC) on the other end.

The BWEC performed exactly as desired. Setup was simple and it gave the speeds we were looking for. In theory, any “wireless to ethernet converter” would work, but I would suggest this one, as it has everything you need including a single antenna port.

The wrt was very helpful, as it has a client signal strength meter built in. Unfortunately, it’s burst and “125mpbs” modes caused it to not pass traffic. Without changing it, that left us in the sub 20mbps (actual throughput). In other words, too little for HD.

The requirements were simple for a new access point, then.
Working “125mbps” mode
Single antenna port
Compatible with our BWEC

Thankfully, Buffalo makes a corresponding access point to the ethernet converter and it meets all of our requirements. Make sure to get the model numbers right, though, as they also sell a slower model that doesn’t have “Mimo Performance*”.

If you try this, we’d suggest a pair of matched routers, regardless of brand. That will make it more likely that they support the same “high speed” mode.

“Mimo Performance*”
As a side note, we should point out that the Buffalo access points used the phrase “Mimo Performance*” in their literature. The “*” indicates that it’s not actually mimo, but is supposed to do a similarly good job of extending range and boosting throughput. While we initially called shenanigans on this, it turned out to pretty much work. The box of the access point said that in “lab tests” they received 34.1mbps throughput. Given that our boxes were hundreds of feet away from each other and we still got 28mbps max (21mbps sustained), I’d tend to believe them.

Where to put access points
So now we have the hardware necessary, but no place to put it. Every situation will be different, but thankfully, ours was easy. In the one story house, we came down from the roof following the pipe into the attic with a 7ft extension antenna cable. From there we ran a new cat5e cable from the attic into the wiring closet using a fish tape to push the wire down the inside of the wall. This wire is connected to one of the lan ports on the access point (note: don’t use the WAN port). Power, for now, is via an extension cable from an attic mounted power outlet.

In the two story house, we couldn’t run a new cat5 down two stories, so we had to improvise. We reused a “phone” (due to the newness of the house, it was cat5e) cable that wasn’t in use by cutting it in the attic and removing it from the phone loop at the wiring closet. Once again, we re-used the attic power connection and hooked through the roof with a 7ft extension cable.

Recap
So far, we’ve installed the physical antennas, access points and plugged everything physically in.
If you’re following along at home, your setup should look similar to the diagram below.

Make it all talk to each other
Now all that is left is configuring all of the devices to speak on the right subnets to each other and not step on each others toes.

IP Addresses and DHCP
If each half of the network (each house) is going to have a separate internet connection, then each network must be on its own range of IP addresses. Choose how you are going to set this up first. In our case, house one is 10.0.0.x and house two is 10.0.1.x. Now, one network will need DHCP disabled. Start with the side that will have DHCP off. Assign the internet gateway the internal address of 10.0.0.1. Set each computer on this network to be on 10.0.0.x with a subnet mask of 255.255.0.0. Now set the Buffalo Access point (assuming it’s on this side of the network) a 10.0.0.X address and remember this address for later.

At the other house, set the internet gateway to be 10.0.1.1 with dhcp on and a subnet mask of 255.255.0.0. Have each client on the network retrieve a new dhcp address.

Note: If you already have a wireless gateway in either house, they can be left on, just make sure to also update their ip addresses too. Your laptops can (and should) still connect to their normal access point, not the new bridge.

Access point configuration and Security
Return to the configuration interface of the Buffalo Access Point (who got an IP address above). Change the channel to “1″ (you may need to try other channels, if “1″ doesn’t perform well) for the wireless and enable WPA-TKIP. Choose a password.

Now, go to the configuration webpage of the Wireless Ethernet Converter at the other house. Note: in our case, this device was on the IP 1.1.1.1 and required us to plug a laptop with a static IP directly to it to configure. You could also assign it to an address on your local network.
From there, do a “search” and find the access point from the other house. Choose it and confirm. Once back at the configuration home page, choose WPA-TKIP and enter your password. Confirm the selection and allow it to restart.

Ping a machine on the remote network. If it doesn’t work, check your Wireless Ethernet Converter to see that it is linked up to the access point.

If it pings, you’re connected now!

To people who want to share an internet connection:
If you want to just share a single internet connection, leave dhcp enabled for the internet router. Then, replace the second gateway in the diagram with a hub or switch. Devices on this switch should be able to retrieve a DHCP address and surf the web as well.

Testing Performance
To see how your network is performing, install Iperf on both sides of the network. Run one side in client mode and then test from the other side.

At this point, you’ll probably need to adjust the antennas to maximize your connection. You can spend days doing this (I promise).

Making Beyond TV Work
After all of this work, it’s refreshing to see that Beyond TV is easy to setup. The easiest way to connect to either machine is to run Beyond TV in “Link” mode from either one of the servers. To do this, add /networkclient:true to the end of the Beyond TV Shortcut in the start menu. When launched, Beyond TV will discover both machines and allow you to pick one. Seriously, it’s that easy.

At this point, if you have a steady 8-9mbit connection, you can easily watch standard def TV and with a 20-21mbit connection, you can watch HDTV.

Costs
Antennas $99ea (Microcenter)
Access Point $65 (Best Buy)
Wireless Ethernet Converter $70 (Best Buy)
Extension Cables for Antennas $7 (Fry’s)
4′ Angle Iron $8 (Lowes)
Total ~$350

Can I do this myself?
Probably. The best part of this solution is that you can map out most of it before spending money. The hard parts are getting the antenna mounted, running the antenna cable to the attic and running the ethernet from the access point/converter to your main network. If you can plan how to do those things, the rest is relatively easy.

Short notes if you’re trying this at home

1. Acquire all hardware and tools
2. Mount antennas on roofs
3. Roughly aim them while mounting
4. Run the antenna cable into attic (or through wall as needed)
5. Run Ethernet cable between access point or ethernet converter to the main hub/switch for the house
6. Configure the IP addresses of the two networks to not conflict (like 10.0.0.x and 10.0.1.x) and set the subnet mask of both networks to 255.255.0.0
7. Disable DHCP on one side of the network
8. Configure the access point on side one (including security settings)
9. Configure the ethernet converter on side two to connect to the access point
10. Test using ping and then iperf for speed
11. Aim antennas (rinse and repeat until max speed is reached).

Future Ideas
There are a few more cool ideas that can come of this setup that we will discuss later.
Some of the ideas we have:

• Using wake on lan to wake up a Beyond TV server that’s in standby so you can access its content. (Note, since the writing of this article, this has been implemented)
• Using Other antennas: cantenna, omni-directional antennas.
• Connecting more than one client to the bridge.
• Bandwidth pooling (imagine using both 6mbit internet connections at once)

Conclusion
This problem is very solvable. In fact, other than the physical differences that will make each installation interesting, it’s downright simple. If a 20mbps connection isn’t required (for which we needed all new hardware), a slightly slower link could be made for even less money with smaller antennas and/or re-used wireless access points.

So, go out and do it. Find a friend and hook up your networks… there’s no excuse now.

Hardware

• 1x Buffalo Access Point Wireless G “Mimo Performance*” Router/Access Point
• 1x Buffalo Wireless G “Mimo Performance*” Ethernet Converter
• 2x Hawking Technology 14db Directional Outdoor Antenna
• 2x 7ft Antenna Extension Cable
  or
  30ft Antenna Extension Cable
  

Antenna Mounting Hardware Specific to your installation

In our case

• 4′ Angle Iron with pre-drilled holes (cut in half)
• 2x 3″ Hose Clamps to Attach Angle Iron to Roof Pipe

Software

• IP Packet Speed Tester IPerf
• 2x Full Beyond TV Installations (one at each house)

Tools:

• Ladder (Tall enough to get on roof)
• Socket Set
• Manual and Powered Screwdrivers and Bits
• “Fish Tape”
• Dremel and Carbon Re-enforced cutting wheel
• Safety Glasses
• Length of Cat 5e
• RJ-45 Crimper and Ends
• A partner in crime

This entry was posted on Monday, April 30th, 2007 at 12:49 pm by zack and is filed under SnapStream Life. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.