Interface Cards & Controllers

Potential of IP CCTV for modern video surveillance of cities

Video surveillance systems based on Internet Protocol (IP) provide remarkable improvement of functionality, including live monitoring, recording the video, and playing back the archives.
Preview, recording, playback

The heart of every CCTV system is Digital Video Recorder (DVR) that processes camera signals (video) for live monitoring, recording, and playing back. Systems based on DVRs have a limited number of video channels - further extension of such a system will require to employ next DVR/DVRs. DVRs can operate as independent units, or can be manged via IP network by an external managing software. An inconvenience of non-IP systems is limited number of frames per second that can be processed/viewed/recorded and limited image resolution of the recorded material. It is especially troublesome e.g. when certain area is monitored by a single camera and image resolution is insufficient for identification purposes.

CCTV system based on DVR
IP CCTV systems are based on PC servers. Their potential is limited only by the features of the components used. In case of higher requirements, it will be enough to change the components that restrict the system capacity. Normally, an extension of the system consists in license upgrade (next channels), and the new hardware does not disturb the structure of the system.

Another important feature of IP CCTV systems is scalability, connected with their distributed structure. The system can be based on a number of servers and client stations. Operational properties of such a system depend on its configuration and access rights of the users. The recording servers and client stations can be physically located anywhere in the system.
Cameras

The main quality feature of a camera is image resolution. Due to TV standard requirements, e.g. in PAL systems it is limited to 720 x 576. Digital systems do not impose such restrictions - image size/resolution can be shaped freely. Aside from popular D1 equipment (PAL-compatible:720 x 576), megapixel cameras rapidly increase market share. 1.3 Mpix camera (1280 x 1024) provides three times the pixels than standard PAL camera. Depending on requirements, there may be used 2 Mpix, 3.1 Mpix or even 5 Mpix cameras.

Megapixel cameras allow to monitor much larger area than standard devices, or - with other lens / lens adjustment - can provide much more detailed images. It is especially important e.g. in the case of identification of license plates.

Large and efficient video surveillance systems are using "intelligent" cameras that relieve the main part of the system of some functions. The DVRs/NVRs only record the video streams that are already compressed in the cameras (and the recording process is triggered e.g. by motion detection performed also by the cameras). Such "distributed intelligence" makes the system more reliable and effective - the server does not have to process all the information, the transmission is limited to the pre-processed data.

Comparison of various resolutions
Video data transmission

Analog monitoring systems were built on the principle "one camera - one cable", so that a 50-camera system required to use 50 cables which had to be connected to the DVRs. Packet transmission allows to change the structure of the system completely. Depending on the transmission media and other factors, there is available certain bandwidth which cannot be exceeded. This is practically the only restriction. If, for example, the bandwidth is 50 Mbps and a single camera is streaming 5 Mbps, it means that the total capacity of the link allows to use 10 such cameras at the same time. The technology does not require star-shaped structure - it may take form of an Ethernet bus, fiber-optic ring, or popular wireless network.

Of course, there is no obstacle to combining different kinds of transmission. As an example - the cameras that are connected to a system wirelessly (via several nodes of local network) can also stream video to the monitoring center via fiber-optic ring, doubled by Ethernet cable.

The architecture of analog CCTV sytem
Client stations

Client stations are the control points of the system. They have to ensure operational control of the system, but cannot influence the core functions that are essential for security and reliability. It reduces a risk of sabotage. The operators have access to images from cameras, can control PTZ cameras, can play back the archives, export some data to external storage media, but they cannot stop recording operations, or switch off the cameras. The control of the system does not change its main configuration, which guarantees safety and stability of the system.

Client stations are often equipped with consoles that make it easy to control PTZ cameras, printers and DVD recorders for archiving purposes.

About the Author

Marketing & PR Department, DIPOL - European distributor of CCTV monitoring, WLAN, TV and SAT TV equipment, and producer of WLAN, communication, TV and FM antennas.

Surveillance Network Cameras For Your Video Surveillance Requirements

To the home owner looking to set-up their first security system for their home, the whole process may seem just like a nightmare.~The total process can feel like a nightmare, for the owner of a house looking to set-up their first security system for the home.~The entire process of setting up their first security system might seem like a nightmare for the typical homeowner.} You will find a selection of terms to deal with, the potentially lengthy installations as they wire your home for surveillance network cameras, as well as the expense of setting up. Nevertheless it isn't really all to difficult, or costly for that matter, because there are icheap alternatives for securing your home. surveillance network cameras  have come down tremendously in price, making them less expensive and available to the common buyer.

Your home or small office can benefit from a various relatively recent technology that are being utilized in network surveillance cameras today. The IP network camera makes use of the companies existing I.T. infrastructure so that there is no need to rewire the whole office to be able to install this type of camera. This lowers possible interruptions to business procedures down to a minimum, because a lot of these cameras are very user-friendly and easy to set-up.

The network IP camera does nonetheless have problems with a few snags in contrast to traditional CCTV security cameras. For starters there is no true standard in terms of resolution, quality, as well as other facets of video surveillance. This can generate problems for including future network IP cameras, even though this is still much more hassle-free than the average CCTV camera. Also, on a per camera basis, ip cameras could be more costly than other video surveillance options.
However the cost of network surveillance cameras have tremendously gotten a lot cheaper, so that the typicalcustomer trying to find a highly dependable and relatively user-friendly video solution for their security problems can simply take advantage. Surveillance network cameras will also be very flexible that they'll even be watched remotely over the web, something that would be achieved with very much trouble in terms of traditional video security installations.

Keep in mind that when purchasing your own security solution, to have a clear cut idea of what you would be needing and how much you would be willing to spend for it. The DVR needs to be your main concern, as well as its recording capabilities and capacity for holding recorded video. Next you should consider the excellence and resolution of the IP network camera itself. Lastly, set up a financial plan for what you would realistically be able to spend on your system.

UTP cat-5 passive balun for CCTV camera system...?

I've been researching CCTV systems - standalone DVRs and cctv cameras - and I've come across something I don't completely understand. I'm looking at using "passive baluns" to connect each camera to the dvr. Now the descriptions in every listing I read says something along the lines of "passive device - no external power required". Does that mean simply that the BALUN itself doesn't need a power supply, or does that mean that when using baluns the CAMERA doesn't need an external power source?

It'd be awesome if the latter case were true, as my company is looking at a 16 camera system, and we'll be running somewhere around 4000ft of cable. It'd be nice if we could just run a cat-5 cable from each camera instead of a video cable to the dvr AND a power cable to a reserved power supply box.

Any suggestions?

p.s. - example of the baluns I'm looking at: http://www.2mcctv.com/product_info-VITEKVTTR1M.html

Thanks!

The Passive Balun means you can transmit a video signal using cat5 cable.

The advantage is that you can transmit video over a longer cable run, usually up to 300m using passive balun. Normal coaxial cables have a limit of around 90m. The twisted cable pairs in cat5 is also good at rejecting electro interferrence.

'No power required' or 'Passive' means that you do not need a powered amplifier or any power source to extend the VIDEO SIGNAL ONLY.....up to 300m.

'Active Balun' is a powered balun which means it will amplify the video signal up to 1200m or so.

If you use the cat5 cable to run power to the cameras, the balun will not make any difference to the distance you can feed power. After 60m of cable, the voltage on most cables start to drop.

If you want a long cable run to power your camera, use a 14v power supply for 12v cameras or 28v psu for 24v cameras. In this case any voltage drop over the distance of the cable will be slightly compensated by the higher originating voltage.

Here's a few tips
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1) Use a balun that has a power connector with it so you only need one device o make video & power conection on camera side e.g see the balun with the dc connector here http://www.cop-security-online.co.uk/acatalog/Shop__front_Passive_system_36.html

2) A trick I did on an installation with long distance cameras is use a 24vAC power supply then I used a 24vAC to 12vDC convertor guaranteeing I could get 12v on the camera end up to 250m away

Hope this helps.

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