Building To Building Wireless Internet Link

[tggzzz]

we all know ubnt does not provide relevant information but, most of you havent even used directional or point to point links before. point to point links using dishes with 1 watt can accomplish a lot more than omni because omni divides that 1 watt into a sphere around it whereas the dish concentrates the 1 watt of energy so it goes much much further.[/]

You do realize that transmit power regulatory limits are almost always ERP or EIRP (e.g. 20dBm EIRP for UK wifi)? That means if you are allowed 1W EIRP you can use a 1W transmitter with a 0dBi omni antenna but if you use a 24dbi antenna on the transmitter, the transmitter power must be turned down by 24dB to 4mW maximum (ignoring cable and connector losses). It makes no difference to range what antenna you use on the transmitter - if you operate legally (and your transmitter is powerful enough to allow the legal maximum EIRP from the antenna). A high gain antenna at the receiver will increase range however.

It does seem that most of his recent posts in this thread match his moniker. I don't know whether that can be extended to earlier posts and/or those on other topics.

With point to point links and both using dishes the dish is made in spec for the frequency and the directed wifi on the other end is also concentrated by the dish allowing for the few measly watts used over kilometers to be picked up even with the energy loss. Whereas with your typical everyday wifi that uses omni both the AP and client use omni antennas which broadcast the wifi in all directions so the energy is much reduced when it leaves the antenna for the exact waves that would reach the other antenna.

As already stated, having a 'concentrating dish' at the transmitter doesn't get you any extra range but it is a good idea as it significantly reduces the interference to other users.

I think you mean "... from other users".

[System Error Message]

in terms of whats allowed for wifi, point to point links are allowed much more dBi than omni

[Monkeh]

in terms of whats allowed for wifi, point to point links are allowed much more dBi than omni

......

Do you actually know what dBi is?

[madires]

in terms of whats allowed for wifi, point to point links are allowed much more dBi than omni

No! Besides some special local regulations the maximum output is limited to 100mW EIRP (20dBm) in the 2.4GHz band and 200mW or 1W EIRP (which requires DFS and TPC) in the 5GHz band. It doesn't matter what kind of antenna you use, you have to lower the output power of the transmitter based on the antenna gain. If you got a 2.4GHz dish antenna with 24dB gain, you have to set the transmitter to -4dBm to not exceed the maximum of 20dBm. We're talking about ISM bands. For bands requiring a license things are different. If you're lucky, your local communications office/regulation allows more power in the ISM bands in specific cases, which usually involves a lot of paper work. BTW, it's dBm, as the value is based on 1mW. dBi is the gain/loss in relation to the theoretical isotropic radiator. Very basic stuff

[tggzzz]

in terms of whats allowed for wifi, point to point links are allowed much more dBi than omni

Oh dear. O dear, oh dear.

Can you tell us what you understand by the terms "dBi" and "EIRP". That might help us correct your misunderstandings.