Outdoor wireless bridge question - what channels?

[igorfi]

Good day Folks!

I need a good advice here. Two buildings are going to communicate to each other with high directional dish antennas (Outdoor Long-Range 11ac Access Point/Wireless Bridge). Each antenna has a bandwidth of 867Mbps. I need to get a throughput of 2Gbps in both directions. Three antennas on each building give 2.6Gbps.

I decided that there will be channel bonding - 80Mhz wide channels. In this case I can have 6 non-overlapping channels (lets assume it is DFS negotiated).

ch 36-48 (--------------) ch 52-64
ch 100-112 (--------------) ch 116-128
ch 132-144 (--------------) ch 149 - 161

Why I am doing this? Well, to avoid co-channel interference. I just assume that in this case I can achieve a throughput of 2Gbps, giving that each antenna is actually MU-MIMO (if this even possible in a Bridge mode with highly directional antennas).

Correct me if I'm completely wrong here... Thank you

 

[COLGeek]

How far apart are these two buildings?

 

[igorfi]

Hi COLGeek!

The buildings are 150 meters away (492 feet).

 

[COLGeek]

Do you have the option to run a single fiber connection between the buildings? It would sure minimize the cost while improving performance and reliability.

 

[igorfi]

Do you have the option to run a single fiber connection between the buildings? It would sure minimize the cost while improving performance and reliability.

You are right. But the thing is, I'm doing a degree project/research, so this is not a real deal. But I had to overcomplicate the task for myself,so that various technologies could be used in the project.

 

[COLGeek]

To what will the antennas be connected to? Does your project also assume direct line of sight?

Did you see this on the datasheet, "0.5 mile up to 400 Mbps"? It looks like even 3 bonded antennas may not be up to the task.

 

[igorfi]

To what will the antennas be connected to? Does your project also assume direct line of sight?

They will be connected to switches (L3). Yes, there will be direct line if sight (park in between, but without any serious obstacles. The buildings are 4 floors high. So the Fresnel zone is clear (i guess, but I will calclate later)

 

[igorfi]

You are right about 400Mbps with 1/2 miles. This will double the amount of antennas. The setup is getting way more complicated. Now the channel width is reduced to 40Mz. I'm not sure now that this setup is even possible. Now sure how antennas will know which transmission is dedicated to it. Using a MAC address probably is a one thing. Not sure what else.

 

[bill001g]

Your main problem when you use DFS is that you can not set anything....the FCC made them remove the ability to pretend you lived in russia. When running it auto mode they tend to pick the wrong stuff and even worse they change on their own.

Best bet is to look at ubiquiti airfiber products. They have something new that runs on 24ghz radios. I have not use any of this high end equipment. I do not know if these top ones are full duplex or half. I know they sell units that run both.

The main problem getting very high speeds out of wireless is that it is half duplex by nature. This means you always have some data collision. The only solution is to have dedicated transmit and receive radios. This is not a standard function "WiFi" but it is commonly used on licensed point to point microwave connections like the cell phone companies use for back hauls.

 

[igorfi]

Wow! This is amazing parthapratimdas! It IS a full duplex PtP 24Ghz antenna. This means that it won't interfere with in-house wifi equipment. The problem is solved now! Thank you guys for your suggestions. Once I finished my degree I will be more often here.