I've wasted the last 3 days trying to get a WRE54G to work, and I've come to the conclusion that it's a worthless piece of crap. So, my needs are simple. I have a box just outside the fringe of my wireless network. I thought that the WRE54G was a great idea, but it turned out to be 3 wasted days of frustration trying to get it to work.
So, how can I extend the range of my wireless network? I really don't want to run a cable to the other side of my office just to run an AP there, what I really want is a wireless repeater of some sort. Is this feasible, or should I just bite the bullet, get a wireless AP and run a cable to it?
Yep. I agree. Such "range extenders" are not terribly useful.
What's the actual range (in ft or meters)? What's in between you and the fringe user? Trees, brush, buildings? What type of equipment is the fringe user using? What type of equipment are YOU using? What kind of speed were you expecting? (this affect antenna gain). Duz the fringe user have the possibility of installing an external antenna, cantenna, reflector, big dish, or similar gain antenna?
Well, you start by disclosing what equipment you have to work with. There are lots of possibilities, but all of them depend on what you've got for hardware, the path, line of sight, fresnel zone, antenna gain, and so on.
My favorite fix is a roof mounted radio. That would be an access point or router runing as an access point, in a waterproof box, with an attached antenna (for no coax loss).
Base unit is a WRT54G sitting on my desk. I've changed the IP to 10.0.0.x (a carry over from my Cisco days), and enabled WEP. I'm currently using Alchemy-6.0-RC3 v2.04.4.8sv, with everything else set at default settings. I have the WRT sitting on one corner of my desk. The route to the remote box is straight through my apartment, across about 300 feet of parking lot and into my sons apartment. His box has a netgear wireless nic (soon to be replaced by a linksys wireless nic). I stuck the WRE on the wall on the side of my apartment closest to his, and I could pick it up at about 40%. So, as is I'm sooo close. My challenge isn't really getting from here to there, I'm thinking a couple of 7dbi antennaes on each end and maybe boosting the power on my end would be good enough to establish a reliable link.
My challenge is what to use to extend the range. I understand I can get another WRT and use it to extend my range - what I lack is knowledge on how to configure it to do so. I could just get a WAP and run a cable through the house, but an all wireless solution would be my first choice.
That's better. A pair of 8dBi panel (patch) antennas would do the trick trick. Sticking an RF radiator "on the wall on the side of my apartment closest to his" is not the formula for success. My guess (reading between the lines) is that you do not have line of sight between your radio and his radio. Line of sight means that you can take a pair of binoculars and actually see your son's radio.
Going through a wall is a crap shoot. If the wall has aluminium backed insulation or checken wire (stucco), you're going to have trouble getting a signal through the wall. Even without metal in the wall, wood and drywall will attenuate the signal considerably.
There's only 4 ways to do it:
Put the radio in the window.
Add an outside antenna via a piece of coax cable.
Waterproof the radio and put it outside with the antenna.
Add a reflector to your antennas to improve the gain:
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So, I'll ask again as I didn't get any answers to my previous list of questions:
- Do you have line of sight from your desk to your son's apartment?
- If not, can you get line of sight by placing the WRT54G in a window (and without trying to go through a wall).
- What is in the parking lot? If you are on the ground floor, the view is highly likely to be obstructed by parked vehicles.
- What manner of equipment is your son using? Does he have line of sight to your WRT54G?
- If not, is there a window that can be used to get line of sight?
300ft line of sight should not be a problem for the WRT54G and most USB radios which have conveniently attached 1/4 wave antennas and can be easily moved to a window location. No need for amplifiers or directional antennas. However, if your son's radio is a PCMCIA card in a laptop, or a PCI card buried behind a computah, you may have a problem getting line of sight.
Ok, so moving the WRT54G into the window will be a big help.
A partial block made out of steel is as good as losing the signal. Can you actually see his antenna through the window from your 2nd floor window? If so, it should (and probably will) work. If there are cars in the way, it will fail.
Simple test: Use binoculars. Can you see your son's antenna from where the WRT54G antennas are located? Even partial blockage is bad.
I forgot to ask: Any metal window screens or aluminized "heat reflective" coating on the windows?
7dBi antenna? Omni or directional? I have limited confidence in any antenna directly attached to a wireless PCI card. Is it this thing? ftp://ftp.linksys.com/datasheet/hga7t-ds.pdf If so, it may be 7dBi gain under ideal circumstances, but not when it's installed parallel to the back of a metal computah box and crammed into a recessed PCI card. They'll work well on the back of a WRT54G, but I wouldn't bother on the back of your son's computah.
The problems with omnis on PCI cards are minifold:
The metal case is far too close to the antenna to obtain decent VSWR (voltage standing wave ratio). The proximity of all the metal will also detune the antenna.
The antenna ends to be tangled in all the wireing and cables found behind the typical PC. Any of this cableing will detune the antenna or mangle the antenna pattern.
Due to the large relective metal surface, the resultant antenna pattern is weird (and probably not what you would expect). Zinc plated steel is also not the worlds greatest RF conductor and will absorb quite a bit of RF.
Such antennas tend to move, which is not the best for long term stability and reliability.
What do you have that does 7dBi of gain? That sounds like a panel (patch) antenna and not an omni. If a panel, and you have a short coax run, it should be good enough. If the coax is too small and/or too long, it may be a problem.
What I've done with PCI cards is make a simple dipole from an R-SMA connector, a piece of stiff coax, and two pieces of wire. Each leg of the dipole is 1/4 wave long or 3.1 cm long. The idea is to get the dipole away from all the metal and wire. If this is too much, buy a panel (patch) antenna and move the omni to the WRT54G.
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like the 8dBi Maxrad panel $25 plus an R-SMA to N-male adapter or pigtail.
As high up as I am, I can still see his antennae with cars there - I'm optimistic but of course won't know for sure until I get the second router in place.
No, this was one of the first things I checked - plastic screen, plastic blinds.
Yes, that is the one. I've played with it a bit, and it seems to give about a 10% increase in received signal strength. Not what I expected :(. I would extend it with a short piece of coax, but not sure if it needs a ground plane or not, I may try it just to see what happens. I'm also tempted to set the computer on it's side so the antennae can stick straight out from the box, and point straight up. But first things first - I'm waiting for the second router to arrive, Fedex says it should be delivered today. Then I start to play and see how far I get, I'm hoping I don't need to start playing with antennaes - it's been 10 years since I put up that 10 meter quad in my back yard, I made it from pvc and told the neighborhood kids it was UFO catcher. I've not worked with anything smaller then 2 meter gear, but this can't be that difficult work with :)
I'll post results once I get the router and play with it a bit....
It doesn't. It has a sleeve balun inside that takes care of any ground plane requirements. It's made to hang on the back of a WRT54G, which doesn't offer much of a ground plane. Try getting it away from the metal comptah box. What's killing the signal is the proximity to all that metal.
Also try adjusting the tilt angle. Don't assume that maximum radiation is exactly perpendicular to the antenna. It's probably tilted upwards somewhat.
Sure. It's a easy test. However, the tangle of wires coming out of the back of the computah will not help things much.
Sensitivity and power output vary radically among different boards. Maybe the new box will help. However, I predict you'll need to put a panel (patch) antenna on one end at least. 300ft is right at the very limit of the range without using aftermarket antennas.
It's quite different from 10meters and VHF. At 2400MHz, very small errors in dimensions and construction result in substantial performance problem. If you've never done it before, you're in for a thrill. Worse, the test equipment necessary to do it right is more than a little pricy.
Since you're a ham, you qualify to build your own antenna. Find an R-SMA to N-Male pigtail:
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build one of the numerous coffee can antennas scattered all over the web. Keep the coax lengths as short as possible. My guess(tm) is that is all you need to make a 300ft shot work. If not, then make a
2nd coffee can antenna for your end but using a R-TNC to N-Male pigtail. If you wanna do your own modeling, let me known and I'll send you instructions.
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Personally, I prefer panel (patch) antennas.
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Oh, yeah. You can also just hang a reflector on your WRT54G.
Continuing on...how do I set the two routers so one is linked to the other, effectively acting as a repeater or range extender? I can connect to either router, but I'm not sure how to link them.
It works! It works! I put the router in my hallway window, 300 feet across the parking lot to my sons apartment. parking shed and someones car in the way. 50% signal strength, seems to be enough to maintain a realiable connection. W00t!
See, that was easy with line of sight. However, you're not done yet.
50% signal isn't really good enough for a full high speed connection. I vaguely recall that the WRE54G will display the connection speed in the status window. (The WRT54G wireless router will not). See what you're getting for connection speed. Your thuput should be slightly less than half that speed. Run some benchmarks to check the speed. My guess(tm) is that 50% signal will give 12 or 18Mbits/sec connection speed. This is probably good enough but is worth checking (and fixing) if it's worse.
I dunno about the parking shed and cars. The will affect propagation and reliability. Basically, if the clearance diameter is slightly larger than the width of the largest antenna, it will not be a problem. Try monitoring the signal strength and S/N ratio (or noise level) to be sure there are no multipath effects. I don't expect problems at 50%, but it's wise to keep an eye on the numbers for a few days.
Drivel: I once installed a point to point link between two buildings in an industrial park. I mounted the antennas 12.5ft above ground level, which is well above the average vehicle. Then I discovered that the height limit for bridges is about 15ft and that many delivery trucks come very close. I also managed to install the antenna exactly where the UPS delivery truck parks for its daily delivery. Adding another 6ft to the mounting pipes ended that mistake.
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