Max range of wireless link

ST

I have a friend who is looking to link/network two PC's running windows. One at home, one in the office. The distance between the two is 300-400 metres approx. with fairly good line of sight ( at the moment anyway, there are a couple of trees between the two buildings). There is a main road running between the two so direct cable connection is out of the question.

1) Can a wireless link be set up between the two?

2) What would the approximate cost be?

3) How secure would it be?

4) If a bus / truck etc. were to pass between the two buildings would the connection be lost?

5) Are there any legal / wireless lisencing issues?

At the moment he is looking at getting ISDN lines installed in each premises.

All advice suggestions will be very welcome.

Thanks.

ST.

fractal

Right:
1. Indeed it can as long as you have good line of sight. Over that distance a few trees wont degrade link quality very much.. A house or a brick wall might though.

2. Cost. Depends how good quality you want the link to be. But 2 wireless cards (~ EUR100) plus 2 antennae (~EUR100) and some cable to connect card to antennae and pigtail connectors (~EUR50) should do it, if you already have two rubbish PC's you can use as routers.. You could use Linux as the operating system or maybe StarOS (EUR60 per licence) which is very good. (Note. Very approximate prices) If you wanted you could. I've also heard that Microtec do good hardware solutions for this job.

3. Using the normal security with wireless (40bit or 128bit encryption on some cards) security isnt great. But you could always use ipsec or tunnel important data over ssh and twill be grand.

4. Bus probably not much trouble as its all glass and easy transmittable through. Truck, possibly connection would go down.. But if the truck is whizzing by twill hardly be noticable

5. 802.11b/g @ 2.4Ghz you can do whatever you want. For 802.11a @ 5.8Ghz Comreg require you to register your link but there is not trouble in that. As long as you stay below power restrictions youll be grand after that. (2.4Ghz I think its 1watt output, 5.8Ghz i think its 2watts you can use.. But dont hold me to that)

Thats my 2 cents.

ST

Thanks fractal, very useful information.

Does anyone know of a good website on this subject?

Thanks,

ST.

Rew

www.irishwan.org

lynchie

Originally posted by fractal

5. 802.11b/g @ 2.4Ghz you can do whatever you want. For 802.11a @ 5.8Ghz Comreg require you to register your link but there is not trouble in that. As long as you stay below power restrictions youll be grand after that. (2.4Ghz I think its 1watt output, 5.8Ghz i think its 2watts you can use.. But dont hold me to that)

Just to correct the power output for 802.11b - Max allowed is only 100mW (milli). AFAIK 1 watt connected to an external antenna would be so strong you could pick up a signal all over Dublin! Cant remember what 802.11a max power is, i think it could be 200mW

Capt'n Midnight

Originally posted by ST
I have a friend who is looking to link/network two PC's running windows. One at home, one in the office. The distance between the two is 300-400 metres approx. with fairly good line of sight ( at the moment anyway, there are a couple of trees between the two buildings). There is a main road running between the two so direct cable connection is out of the question.

1) Can a wireless link be set up between the two?

2) What would the approximate cost be?

3) How secure would it be?

4) If a bus / truck etc. were to pass between the two buildings would the connection be lost?

5) Are there any legal / wireless lisencing issues?

At the moment he is looking at getting ISDN lines installed in each premises.

All advice suggestions will be very welcome.

Thanks.

ST.

At that distance two panel antennas should do fine if they can see each. - It's line of sight - so unless the buses are transparent to RF so the link will drop while the bus is there.

costs / commercial advice - www.vbnets.ie

secure - turn on all the settings - but if you want real security buy a leased line, or use a third party VPN and treat the RF link as secure as packets out on the internet.

Regulations - 100mW EIRP - ie. Multiply the power of the card by the antenna gain Eg: 25mW + 6dB = 100mW EIRP

ISDN - madness - pence per minute - if ONE device at either end autodials (DNS / Ping whatever) for a month it would pay for RF or ADSL for a year

ADSL - could use VPN's with this too - better than ISDN - get netsource or someone else who can give you static IP addresses at each end.

================================

You can tunnel under roads - there is a machine with a pipe that does it - 4" hole or something
Or start training moles.....

ST

Is it possible to set up a direct link without routers between the two PC's, like a "Direct Cable Connection" except wireless?

Michael Collins

Is it possible to set up a direct link without routers between the two PC's, like a "Direct Cable Connection" except wireless?

Yep, just use Ad-Hoc mode which is available on all Wireless Cards

fractal

Acutally heres a good post on the irishwan.org forums about power outputs and whats allowed

http://www.irishwan.org/board/printthread.php?t=100&pp=40