Advice needed on connecting my neighbour to my wireless setup.

I have a wireless router in my house and was wondering about hooking up my neighbour to give them access to my broadband,

Their house is 150 ft across the road and the signal would need to go through 2 external walls and probably a tree or 2.

My router is a 3Com 54g OfficeConnect

What hardware would I need to get in order to make this work. Money is an issue I am afraid so the cheaper the better.

many thanks

Harry

If you can't decide on the number of trees, follow the leaves down to the trunk, and count the number of trunks. Actually, what would be more interesting is the type of leaves and how many feet or meters of tree the signal will need to penetrate. In general, about 10ft of broadleaf tree is good for a -10dB signal lost. At 150 ft, with decent antennas, it is close enough that one could "drill" through the leaves, especially if one can see something between the leaves. However, if the tree is really dense, then it probably won't work.

The walls are a similar problem. Without the slightest clue as to their composition, it's difficult for my crystal ball to predict the propogation characteristics. How thick? Any aluminium foil backed insulation? Any chicken wire? Any concrete? If so, forget it. The signal won't go through.

No it's not. 3com makes about 5 routers that fit that description. Kindly disclose the model number (3CRW_____) so that I can determine if the antennas are removable or not.

The cheapest way is to get a decent wireless client radio at the neighbors with a decent high gain antenna. Plant it in a window. Move your 3com access point also to a window. Take your chances with the tree. The trick is that the antennas must have some gain. I don't think it can be done with the stock rubber duck antennas. I suggest an 8dBi or 14dBi panel antenna such as one of these:

"Antenna Panel" as their webmonster seems to be making a concerted effort to prevent anyone from bookmarking anything other than the home page. Sheesh).

However, the use of such external antennas assumes that your badly specified 3com wireless router has removeable antennas. If not, or if inconveniently located, it will be necessary to add another wireless access point for the link. You can also use a wireless router as an access point by simply ignoring the WAN port, setting the IP address to something not duplicated, and disabling the DHCP server. The LAN port of this access point goes to one of the LAN ports on your existing 3com wireless router.

My guess is that a pair of WAP54G access points ($70/ea), setup as a wireless bridge so that the neighbor can connect more than one computah, will work. Two 8dBi Maxrad antennas at $25/ea. Two pigtails at $10/ea. Some CAT5 cable at $5. Total is $215 plus tax and shipping. Probably a bit high, but it will work if your countless number of trees aren't too thick.

The trees will be the killer here. Is there no true line of sight possible? If you can not find a line of sight then you will not succeed. If there is a line of sight, then use external aerials and it should work very well, but keep the aerial cable as short as possible.

David

One serious problem with this can be multipath reflections off of passing vehicles, or worse yet having a vehicle pass that is large enough to simply block the signal entirely. E.g., a large van parked on the roadside in just the right place can totally kill the signal! If one or the other (hopefully both) buildings has a second story, it is significantly better to have one or both units in facing windows that are elevated above road level.

Try aluminum foil; it works just as well and is much less expensive than silver foil... :-)

I did a little fooling around with that concept awhile back. I found that without careful adjustment it is possible to get 3-4 dB gain with a very crude reflector. The trick is proper spacing between the reflector and the antenna. It should be just about exactly 4 inches.

The size of the reflector, and for that matter the shape, don't seem to be very important. Another 3 dB, at least, can be squeezed out perhaps with shaping and *very* careful adjustment of the spacing.

Ok, it's probably too expensive. So, make your own antenna. Methinks the biquad at:

the easiest to make. Forget the pigail and just use a fairly short coax cable run to whatever connector is on the access point or wireless router (R-SMA or R-TNC).

There are also proponents of the coffee can antenna:

of other sites with cantenna plans.

If the antenna on the 3com access point is non-removeable, then a simple reflector will be a big help:

You might consider a 2nd access point on your roof, in a waterproof enclosure, and with an omnidirectional antenna. Supply service the entire neighborhood so you can dilute your monthly broadband charges accordingly. Be sure to check your ISP's terms of service or you may get unplugged.

Since the neighbor is across the street, you might investigate if there are any common drain or utility pipes that might be used to run wire, CAT5, coax, or fiber across the road. I've done this a few times when faced with political or LATA boundaries. I've also run my own cable between telephone and power poles with mixed results. The power and telco people have generally left things alone, but the maniacs that clear off the weeds around the base of the wooden poles were not as tolerant and chopped up my cable with a weed whacker. If you've never climbed a pole or done utility work, I would recommend you get some qualified help as you really only have one life to give for your neighbors connectivity.

I would mount your router in a weather proof box outside on the wall and you should be able to do it, if not then your neabour would need to get a dish antenna and point it at your router.

I do it this way with my neabour, he is across the road and down 4 houses, we get decent speeds and solid connection 24/7.

If your neighbour is across the road then it's fair bet that you have facing windows, angle is not a problem. Just place your router / AP on the window sill and your neighbour will need to place USB adapter (on up to 5m of cable) on his window sill. If necessary you can place silver foil on card, bent to a VS. shape or parabolic arc behind either or both. That's what I do, works a well without any silver foil, but with steadier signal strength / quality with the silver foil. Regards, Martin

Just how big is the antenna in a DWL-122 dongle? If it is shorter than a halfwave dipole you might actually be getting a very different effect than I am with the longer dipoles used for "fullsized" antennas.

There are some similarities, and some significant differences, in feeding a parabolic. For example, take a look at any of the satellite TV antennas, which are Ku band (13-14Ghz). I don't see the small dishes that are used elsewhere, but for example the 1 meter dishes that are common here have a feedhorn that is almost a couple *feet* from the reflector! That's several wavelengths!

The main difference is that with that design the only signals of significance are those reflected off the dish into the feed horn (a unidirectional antenna used to "illuminate" the reflector).

Since we are using a reflector behind an omni-directional antenna, both reflected and incident signals are used, and the spacing is adjusted not to obtain full illumination of the reflector, but rather to phase the reflected and incident signals so that they add rather than cancel when they come from the right direction. A whole different animal.

Science? That is the theory developed, post facto, to explain what happened when you experimented... :-)

Actually, the first time I tried it, I purposely put a WRE54G repeater very precisely the length of its antenna away from a the side panel from a computer case. I fully expected it to change as it was moved, and thought it might get better at longer distances. Much to my surprise, it didn't. It was no surprise that going closer didn't help either.

Now, consider another factor though. If this is changed from a simple reflector into something at approaches a waveguide, for example if the foil is on a cardboard box and covers the sides as well as the back... it is a very different beastie. It would be very similar to a cantenna, and the distance might be much shorter than 4 inches.

antennas.

Its a 3crwe754g72-a

Four inches! Youch! I didn't even try out that far. In near range, about 3/4" (a handy chunk of Styrofoam) taped to a 9" pie plate, with a DLink DWL-122 dongle taped to that, seemed to give noticeable improvement. I tried a few distances, but not out to four inches.

Later I moved to a coffee can, which I think was better due to some side rejection. I didn't try any parabolics, but the parabola at freeantennas.com would have been far less than four inches. On the other hand...

Four inches? Was there science for that, or just experimentation?