Point to point wireless

Forums › LAN (ethernet/Wifi/routers/Bluetooth) › Point to point wireless

nate

6473 posts

Uber Geek

Retired Mod

Trusted

Lifetime subscriber

#29800 20-Jan-2009 01:06

Mate is trying to run a network cable between two houses on his property about 100 metres apart. Digging a trench won't work as there are obstacles in the way. There is line of sight between the two.

Can anyone recommend a wireless solution and a supplier?

richms

28192 posts

Uber Geek

Trusted

Lifetime subscriber

#190683 20-Jan-2009 01:37

2 routers capable of running openwrt, and installing openwrt on them.

If signal is an issue then start to look for antennas etc but 100m is IME easily achieved by the usual gear once the power is taken up to 100mW

Richard rich.ms

scottjpalmer

5973 posts

Uber Geek

Moderator

ID Verified

Trusted

Lifetime subscriber

#190687 20-Jan-2009 06:40

Talk to chris021 - and then report back here what solution it was he used.

freitasm

BDFL - Memuneh
79308 posts

Uber Geek

Administrator

ID Verified

Trusted

Geekzone

Lifetime subscriber

#190699 20-Jan-2009 08:36

The Netgear HD/Gaming kit we reviewed is made for that, although by LOS I believe you mean from the rooftops?

iainw

75 posts

Master Geek

#190709 20-Jan-2009 09:17

Most consumer AP's only transmit at around 25mW (14dBm).

Transmitting at 14dBm, means that both ends of the link need antennas system gains (antenna, cable, surge protectors) of at least 8dBi. This assumes that you have to use 2.4GHz as this is the most common on consumer grade equipment. This gives you 54Mbps of 802.11 throughput, which is around 22-24 Mbps user data. You can work with less, just depends on how much user data you want to put through. You also need to consider SNR, as 2.4GHz is so cluttered, you may end up with less throughput.

Lightening arrestors are highly recommended. It doesn't protect you from direct lightening strikes - nothing does. It will however protect from nearby strikes, and also from static build up due to windage. Yagi antennas are recommended as they are much easier to aim than patch or panels. They are more susceptible to windage however. Make sure the antennas have their polarity aligned correctly (verticle vs horizontal vs circular). Incorrectly aligned polarisation can introduce as much as 30dBi of attenuation which will completely bugger any wireless bridge.

RF LOS for a 100m link at 2.4GHz, is a 1.1m radius "tunnel" around the laser LOS. If you can only just see the antenna, this is not enough - google search for Fresnel zone for an explanation.

Best solution is to hunt for an AP that supports 802.11a, this requires slightly higher gain antennas, but is less noisy, and has a smaller fresnel zone (0.7m).

Do the math first. You could just wack something in, and it may even work. But it will be by luck rather than design, and it will be much harder to troubleshoot, and will require a lot more work to keep it up. How reliable do you want it to be?

If you want recommendations of people that can do it for you, drop me an email and let me know where in NZ you are. I have a network of RF expert partners I can put you in touch with depending on location.

cisconz

cisconz
1342 posts

Uber Geek

ID Verified

Trusted

Lifetime subscriber

#190735 20-Jan-2009 10:29

Try one of these. I was suggested it by Tomizone for backhaul accross the viaduct.

Hmmmm

eXDee

4032 posts

Uber Geek

Trusted

#190863 20-Jan-2009 18:03

http://www.gowifi.co.nz/ i've heard is good for enquiring about wirelesss solutions.

cyril7

9058 posts

Uber Geek

ID Verified

Trusted

Subscriber

#190871 20-Jan-2009 18:31

+1 for sourcing kit from goWifi, a pair of NanoStation Loco 5's would do the job nicely and not much more than what you would pay for more domestic kit, but by the time you put domestic gear in a weatherproof cabinet and sort antennas youve well passed the price, and still have a cludged result.

Cyril

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

mushion22

297 posts

Ultimate Geek

Trusted

#191513 23-Jan-2009 11:59

Maybe consider an 802.11n bridge for better throughput if you want >25mbps.

iainw

75 posts

Master Geek

#191516 23-Jan-2009 12:07

802.11n bridges will give greater throughput, but don't expect to get anything near the speed increases you would inside.
To get 150+Mbps from 802.11n, relies on the presence of strong Multipath (signals bouncing all over the place), which is not present in an outdoor environment.