Question : Setting up wireless bridge between adjacent buildings

We have an existing LAN network on the first floor of a six story building in a downtown location.  We are busting at the seams, so we have leased the fifth floor of the building directly across the street.  I'm anticipating we will eventually have as many as 20 people over there (current office has about 35).

I will need to extend our existing LAN to this new space, but there is no way to run wires, so I'm looking into a wireless bridge as the solution (all PC's will be wired...the wireless will ONLY serve as a point to point bridge).  Line of site is almost perfect.  There is a single street light post.  Total distance is MAYBE 90 feet.

Here's the tricky part:  Because we are leasing these buildings, we most likely will NOT be allowed to mount antennas on the exterior of the building (yes, I will probably ask permission anyway, but want to know my options), so I am looking for a solution that will allow me to place the antenna's  in windows.  

Again, excellent line of site, but we will be going from the first floor on one side of the street to the fifth floor on the other side, so I wonder if that will make this more difficult.  Other floors of each building have other tenants.

I'll also have to deal with phones...I don't want to install a separate phone system over there.  I'm considering replacing our existing Nortel MICS with a VOIP system (I've got experience installing them anyway) and thus eliminating the need for a separate solutions for phones.

Any and all suggestions are appreciated.  I'm got good networking skills, but my wireless experience is limited, and I've never had to spec any antenna's that weren't built into the wireless device.

Answer : Setting up wireless bridge between adjacent buildings

If you know who owns the other antenna, you might ask them the frequency and channels they are using. It would really be helpful to know this in deciding how you set up your network. Can you tell if it is a patch antenna (like a rectangle to square shape, a dish or is it just a bridge using normal internally attached antennas.

Now that you know where you can mount it, we can work on what you need to do so. First, you need to figure out how to get your rj45 up to the roof and determine the type of equipment you need. Bridges with POE (Power over Ethernet) and ones that are encased in an outdoor encloser is a start. You will need a POE injector ,protection from lighting, mounting hardware, a couple of cables (or one, depending on the antenna, or none) dpending on the bridge hardware.

Also how much is your budget.