Wireless CCTV system (15pcs 2Mpix) - 0.2-3km distances

[kt00 0]

Hello!

 

The main target is to monitor 15pcs 2megapixel cameras at two central locations ('PH', 'R' in the attached pdf).

 

There is a wired backbone with 3 headstation (I,II,III) as you can see on the attached plan. The headstations and the monitoring centers are sharing this 10Gbit wired connection. The 15pcs IP cameras needs to be connected to the backbone throught the headstations, using wireless (5Ghz) connections.

We have built some wireless systems before, but only 4-5ip cams and small distances (50-100m). Have lots of experience with structured networks and with IP networks in general. But this one is different because the long distances and the count of the IP cameras. We are counting with approx 100Mbit bandwith take with the 15pcs ip camera (5Mbit/sec per camera), thats not a problem i think. For split screen monitoring the cameras we will use CIF secondary streams, 2mpix streams will be used only for selected/full screen camera monitoring.

 

Please any recommendations on choosing the right APs and antennas? Was working with nanostaion M5 APs before, but never used anything other then the built in sector antennas (only small distances). Some help would be greatly appreciated. My opinion on the APs/Antennas:

 

Headstation I (cam1,2,4,5)

For cam1/2: Rocket M5 with 90deg 20dBi sector antenna?

For cam4/5: Same AP and antenna? But maybe the 4deg. elevation beamwidth wont be enough so we should use two point-to-point link for this two camera?

One Point-to-Point link for camera 3?

 

Headstation II (cam6,7,8,15)

Lots of differences here on the distances, so we need four pcs AP/sector-antenna pairs (four Point to Point link)?

Should we use Rocket M5 with GPS function? I read that its recommended with more than two APs on one tower because of interference, even with using different channels. (gps function - TX synchronize)

 

Headstation III (cam9,10,11,12,13,14)

cam10,14 : AP + 90deg. sector antenna

cam11,12,13 : three point-to-point link?

cam9 : nanostation M5 with built-in sector antenna? (one point-to-point link)

 

What Access points to use at the station (ip camera) side?

 

Line of sight is no problem, the terrain is totally flat. Keeping fresnel zones in mind (towers etc), but what device to use for to check the scenes for interferences? Any help would be greatly appreciated!

[hardwired 0]

I'll look at this in more detail later, but a few things come to mind.

 

Use shields on the sector antennas http://www.rfarmor.com/cart/ , and keep in mind that Ubiquiti rates their sector beamwidth edges at -6dB, not 3dB like others, so their 90 degree sector is more like 60, and the 120 is closer to 90 degree.

 

Nanostation M5's for the closer cam locations should be fine, Nanobridge M5's for the further shots. Shoot for a -50 to -60 signal on everything.

 

If you take the information from the Ubiquiti stuff (gain, transmit power, receive sensitivity) and go on over to Ligowave's site http://www.ligowave.com/linkcalc/ and sign up for a free account there, they've got a great PTP and PTMP calculator.

 

**********Edit********

 

The newer Ubiquiti M series stuff has a pretty useful spectrum analyzer built in.

[kt00 0]

Thank you hardwired!

 

You mention rfarmor for shielding but can the ubiquiti titanium series be used for the same purpose?

 

Other question im uncertain about is that where can i use point to multipoint links 'safely'? For example at headstation I* (cam4 & cam5). Using a 90deg(horiz bw)/4deg(vert bw) 20dBi sector antenna is sufficient for pick up the two cameras or its better to go with PtP connection?

 

*I have attached a little draft about this scene, i know beamwiths are not this perfect straight its really just for demonstrate my problem.

 

Is it recommended to put rocketM at the headstation tower where im going to use PtMP connections and nanostation M5 at the cameras side(stations)? If we have to install for example 4-5 antennas (PtP) on a tower, for what should we pay attention? Channel distribution, the mentioned isolation with custom shielding, maybe rocketM ap's with GPS function and vertical separation. Anything else needs to be care of? Or better to use nanoBridges?

 

Your help is greatly appreciated, thank you hardwired.