Wireless recommendations

[Benjamin Waldon]

Hello,

I have an opportunity that I would like some feedback on.

I have a client with two buildings approx 1400 feet apart. They currently link the two offices with a T1. However, they would like to replace that T1 with a solution that could provide 100mbps or more throughput. All traffic will need to be encrypted.

The problem is that they don't have line of sight. roughly half of that 1400' is wooded area.

So, what would you be looking at? Could bridges with Yagi antenna penetrate the woods? What about dish antenna? I want to say that any Cisco bridge is going to come with the ability to encrypt the traffic.

If we used 802.11n, would we be required to purchase multiple antenna to facilitate the MIMO benefits?

Thanks,

Ben

[Dennis Kline · Accepted solution]

I've used a lot of WiFi bridges, as well as designed many point-to-point microwave links.

Some will attempt to tell you that true line-of-sight isn't necessary, but I will tell you differently.  Foliage (depending upon the type of tree) can seriously attenuate RF.  This is especially true when the leaves get wet from rain or dew.  The path may work great in the winter, but in the spring when the trees start to bud, the signal will deteriorate.

You'll do much better going from roof-top to roof-top with line of sight.  For that short of a distance, you really wouldn't even need 1st Fresnel zone clearance.  If the roof tops are not high enough, think about a small mast on each end.

But I think you'll be disappointed in trying to "burn through" the trees

But (as I always say) - I could be wrong

Message was edited by: Dennis Kline - because I can't spell  when multi-tasking

[Leo Laohoo]

If we used 802.11n, would we be required to purchase multiple antenna to facilitate the MIMO benefits?

Point-to-point wireless bridge using "n"?  Not yet supported.

The problem is that they don't have line of sight. roughly half of that 1400' is wooded area.

Trees grow.  If you have "line of sight" you'll loose it when the trees grow higher or thicker.

How about investigating to have black fibre put in.  This way you have the option to push 1, 10, 40Gb per fibre link (single mode).