CCTV over Wifi……saving cash on analogue RF !
The scenario.
Picture the scene (pardon the CCTV pun!)
Building A is 500 metres from building B
There are 4 cameras on building A, one on each corner (don’t you just love perfect worlds!) and they need to be viewed, recorded and controlled (did I mention they were PTZ?) all from building B
THE PROBLEM
The two buildings are separated by a river – a very nice river, big boats coming up and down, delivering stuff to dockside delivery points.
No chance of cabling then….. Until recently, the answer was to use free range wireless transmission solutions, such as RF, Microwave, Laser etc……… but, history shows that each has it’s positives and negatives but they all share one common negative….. expense.
ANOTHER WAY?
With the upsurge in IP, there is another way………..Wifi…………ok, professional wireless is what all the proper ‘wifi’ consultants will call it, but wifi nonetheless.
You see, Wifi does not have to be a one to one transmission solution…………. with typical bandwidth of 54Mbps, even if we halve it (because clever network guys will tell you that there is always a drop over distance etc), we can expect a 27Mbps bandwidth allowance……
So, take our building A and B scenario…. cable all the 4 cameras to a central point (it is a perfect world after all !) and either convert to IP from analogue using encoders (or, if we are to get this industry into the 21st century let’s push the boat out and go true IP cameras!) and connect to a regular 4 port network switch…
Take the output of that switch and insert into something like the Silvernet product range….. 1Km line of sight, pre-configured to create a point to point connection…..go to building B, position the receiving unit line of sight to building A and either decode back to analogue or bring one, neat, simple CAT5/6 cable out and introduce to the network for full control and view of the system ! simples !
THE THEORY AND THE PRACTICE
Ok, we don’t always have a perfect world, clearly, however, using the above solution, we have sent 4 cameras over the one link….saving a LOT of money:-
RF/Microwave/Laser = at least £2000+ for EACH camera
WIFI = under £1000 for a 1Km link with the ability to run a good few cameras – typically a PTZ IP camera would be around 5Mbs and a static at around 2Mbs
But, just like RF/Microwave/Laser, if the Wifi states ‘Line of Sight’ or LoS, then it REALLY means that…..so much as a leaf on a overhanging tree, or, in the case of our River separating the two buildings, boats that might momentarily ‘interrupt’ the signal, it is imperative to ensure that the TX and RX units are positioned so as to enjoy clear and uninterrupted transmission!
The cost savings are impressive and just might give this industry the excuse to use IP !!
