One of my first major projects after we moved here to the House of Cornelius was to implement a campus-wide wireless network. Part of the motivation, of course, was to get our own house online since I still manage my shareware business and also handle all IT operations for IFM. The House of Cornelius has a pretty decent DSL connection that is 768Kbps down and 256Kbps up. It's actually quite amazing considering how far we are from the main phone office. Apparently we are at the absolute limit of the service range. The DSL phone line and modem are in the main office on the campus while the staff housing is all in separate buildings ranging from 400 to 800 feet away. So the first order of business was to set up a base antenna on the roof that would be the foundation of a campus-wide wireless network.
Before starting, I did some simple experiments with a Linksys wireless access point from the local (30 miles away in El Paso) CompUSA. With an extension cord and a 50 foot network cable I placed the Linksys on the roof of the office, then tried surfing the web at my house approximately 500 feet away. I could access the network and surf the web only from the end bedroom that was nearest to the office, but this was pretty good! I was expecting the need for a directional antenna at each house, so being able to connect at all - from within the house with no extra hardware - was encouraging.
Next came the research phase. There really isn't a lot out on the net about setting up a campus-wide wireless network. It seems to be the realm of consultants and companies that want to sell you their services. But I was able to piece together various people's experiences and product descriptions to come up with some pointers. The first thing I noticed was the predominance of the D-Link wireless access points. They seemed to be the radio of choice. CompUSA had a D-Link DWL-2100AP for about $100 and so I had settled on a Linksys that was $30 cheaper. The only hitch was that the Linksys had two antennas instead of one. In my research on outdoor antennas I had settled on the 12db Omnidirectional HG2412U from Hyperlink Technologies that seemed to fit the bill. But it was expensive enough that I didn't want to buy two. So I ordered just one and planned to connect to one side of the radio. Then the hurdles began...
The first hurdle was mounting the antenna which took some time but was pretty straightforward. The antenna is about 4 feet long and is mounted to the end of a 8 foot piece of 1.5 inch conduit, which is clamped to a piece of 2x6 lumber, which is screwed to the facia of the building. The conduit, being an excellent lightning rod, is grounded with a standard 8 foot, copper grounding rod and 10 guage copper wire. David Wolcott helped me quite a bit with the project.
The second hurdle was the cable. I glibly went to the local (30 miles away in El Paso) Radio Shack to get supplies to build a cable for the antenna. I had to go to two different stores, one twice, to find all the pieces. I bought 50 ohm coax and some twist-on TNC connectors since the Linksys and the antenna I bought used TNC. Little did I know that not all TNC connectors are created the same! The cable looked great when I got it done, but it wouldn't connect to either the radio or the antenna. It turns out that all the wireless computer products use nearly proprietary “reverse” versions of the common connector types. The Linksys uses an RP-TNC connector which is kind of a TNC turned inside out. Ugh. I took the connectors back and had to eat the cost of the cable itself. I then ordered a cable from Hyperlink Technologies. But since they really only sell to consultants and companies, they didn't have any information about which one of the five or six varieties I should buy. They were all 50 ohm but of varying thicknesses. I took a guess. Fortunately, it seems to work.
The next hurdle was supposed to be so simple; range testing. How far away from the antenna could I get and still have a surfable signal? Remember that the antenna was plugged into one of the two antenna ports on the back of the Linksys access point. I thought, if it would work, then I would have one inside the building and one on top for dual coverage. It seemed to work, but it really didn't. I could get connected inside no problem. Outside it would work reliably up to a point, then with wild variability beyond a certain range. I was inspired to try the configuration because I had seen pictures on the web of some guy who webcast his wedding. He had an external antenna plugged into one of the Linksys antenna ports. It may have worked for him, but not for me. My theory is that it only worked outside as far as the inside antenna would reach through the building. The roof antenna would produce a signal that could be detected far away, but I could not reliably connect. Strangely it seemed to work at first and so I bought another matched Linksys access point from the local (30 miles away in El Paso) CompUSA for my house so I could brindge the two LANs. But then it went wacky and wouldn't work at all. So I went back to the local (30 miles away in El Paso) CompUSA, returned the Linksys devices and got the D-Link DWL-2100AP. Unfortunately, the D-Link has an RP-SMA connector which no one in El Paso carries, so I had to order a “pigtail” cable from Hyperlink Technologies to convert from RP-TNC to RP-SMA, which introduced a four or five day delay. Finally the pigtail arrived and I could plug in the D-Link. Success! It worked wonderfully and I could surf the web again from the end room of our house. The signal still didn't reach further into the house and it was weak, but it worked!
The next phase of the project was making a wireless “end point” on my house. I went back to my local (30 miles away in El Paso) CompUSA and got another D-Link DWL-2100AP, a hub, and a 12db, very directional Cantenna. The Cantenna is a very simple device. There are plans for making antennas like them all over the web. The catch is finding the connectors! I decided to splurge, save the time, and just buy one. I set it up inside the house and pointed the thing at the base antenna through the girl's window. Wow! The result is a solid near-LAN-speed connection to the base antenna. Then the hurdles began again.
The next logical thing to do was mount the antenna on the outside of the house. I found a nice bracket at the local Ace Hardware (truly local), mounted the antenna under the eave, drilled through the end of the house, mounted the D-Link radio inside on the wall, and got ready to work...only it didn't work. Arg! All this work and now it has mysteriously stopped. Could I have damaged the antenna or the radio? I checked everything. The arrangement worked in the house, but not through the wall. Finally it dawned on me...the antenna is polarized and I had mounted it on the house rotated 90 degrees! I bent my bracket and am now in business.
Now that it was all working at my house, it was time to concentrate on the base station aagin and clean things up. The first thing I did was to tidy up the cables with wire ties and then to mount the equipment on a board on the wall. It all looked so great! Then I went home and found that the system had mysteriously stopped working. Arg! Over the next several hours I retraced my steps, undoing each thing, walking back to my house, testing, until it started working again. I got lots of exercise that's for sure. I found that the system would not work if the antenna cable was strapped to the mast. After much thought and agitation, I have concluded that when the inline cable lightning arrestor touched the mast, the system stopped working. Perhaps it was effectively changing the length of the antenna? It's a good guess perhaps. Anyway, I put some rubber between the lightning arrestor and the mast, strapped it back down, and it's all back in operation.
The next phase of the project was to get the other staff housing online. The Wolcotts live next door so I set up an old Dell Truemobile 1184 wireless router as an access point since they had two notebooks with wireless cards. The idea was to connect it to our house LAN and broadcast it to the Wolcotts. It seemed to work well, but over a few days I noticed several strange things. Their computers would take may minutes to acquire an IP address from the base DHCP server. I also noticed that my D-Link DWL-2100AP saw the Dell access point and seemed to divide its attention. When I first set it up, it said it had 85% or better signal strength through the Cantenna. But with the access point in my house for the Wolcotts, it got about 40% from the base through the Cantenna and 60% from the access point in the house. I tried changing channels on the Dell and reconfiguring the Wolcott notebooks, but I could never get it to work. Ultimately I had to abandon the idea.
While on a trip to our local Sam's Club (30 miles away in El Paso) I saw some nifty Linksys USB wireless adaptors that came with six foot cables and a little stand. I bought one, wondering if either of the two staff houses nearby could connect to the main antenna with them. The houses are closer than ours, so it was worth a try. The Hutchins live the closest to the main campus, but in a straw-bale home. The house is awesome. It's cool in the summer and warm in the winter, has a nifty Southwest look, and is a pretty sizable house. The catch is that it seems to attenuate wireless signals. I took the adapter to their house, plugged it into my notebook computer and was surfing at 54MBps within minutes. It was great! But it was a fluke. Later, after they had set up their own computer, we tried it again and could only connect once in a while, and then only if we were holding the antenna up in the middle of their hallway, while standing on one foot with one arm extended, and only in odd hours of the day. Arg! The good news is that I tried the antenna at the Wolcotts house and it worked. It still works to this day! So the Wolcotts' house did not require any fancy hardware or antennas.
Mike Hutchins is a man of action. As soon as we could possibly do it we drove to our local (30 miles away in El Paso) CompUSA and bought a Cantenna and a wireless PCI card for his tower computer. Our thought was that if the small, USB wireless adapter almost worked, then surely a Cantenna in the house would work. But it didn't. It only worked if it was sitting in the middle of their hallway. It was slightly better. If properly positioned, it would work reliably. But the position was not workable. So the next day I drove to our local (30 miles away in El Paso) CompUSA and bought another D-Link DWL-2100AP, and a “rainproof” utility box and some outdoor-rated CAT-5 from the local (30 miles away in El Paso) Home Depot. (Fortunately, I got it all in one trip.)
Mike and I surveyed the outside of his house for possible Cantenna locations. Then we peeked in the attic and quickly decided to avoid it if at all possible. We finally settled on the swamp cooler and air ducts as the easiest possible route. The swamp cooler sits on the roof and pumps delicious cool air straight down to a central air duct that runs the length of the house. Their computer is in the living room, so it was a straight shot out the end of the main duct. So we ran the outdoor rated CAT-5 and some Romex wire through a small opening in the duct on the roof, down and out the end of the main duct. I had a fairly long, small and supple extension cord that I cut the end off of. I wired the main length to the Romex with wire nuts inside the air duct. That way the smaller, more supple power cord and CAT-5 cable could be easily run down the wall to the computer. It looks slightly tacky, but it's not bad. The other end of the power cord ended up inside the rainproof utility box to power the electronics. The utility box contains the D-Link DWL-2100AP. It has some flexible conduit out the bottom for the cables. The Cantenna's wire runs into the box through an electrical tape “gasket” I made. The whole thing is mounted to the access panel of the swamp cooler. Once wired up, it worked perfectly. Success!
So now there is only one remaining staff house to set up. It is over 800 feet away from the base antenna in the opposite direction from the Hutchins' house. I don't intend to try anything except the trusty D-Link DWL-2100AP and a Cantenna.
--Thaine