(htemraz) #1


1- CCTV camera is connected to the Ethernet data network
2- A network Camera has its own IP address and has the computing functions to handle network communication
3- The camera may be motion detection (the camera is work when there is a motion in its monitoring zone)
4- The Network Camera has software for FTP server, Web server, E-MIAL Server…etc
5- You must know the sequence of the image production
a- The light is fall on the lens with different wavelengths (Light signal)
b- The light signal transformed to Electrical signal (Analogue signal)
c- The Analogue signal converted to Digital format
d- The Digital format transferred to the Computer functions where the image
compressed and sent out over the data network as illustrated


The Schematic clarification
1- The lens focuses the falling light onto the image sensor (CCD Coupled-Charged Device)
2- Before reaching the light to CCD it passes through the Optical Filter which remove the infrared light so that the correct colors will be displayed
3-the image sensor (CCD) converts the image which composed of light information into Electrical signal
4- The image digitizer convert the Electrical signal from the Analogue format to the Digital Format then the image compressed and transferred to the computer function to sent out the Ethernet data network

System Components

1- Camera
The camera is the core of the CCTV system. It is the device which picks up the light and converts it to recognizable picture then this picture can be sent over the network. The camera sent the image to the viewer at a frame rate the human eye requires approximately 17 frames per second to view the image as live. The transmission media as the coaxial cable
2- Fixed Network Camera
The fixed network camera as similar to the above but with more options to be able to send the images over the Network. This camera is plugged to the network so it is not need to the coaxial cable and the monitor will be the network computers
3- Network Pan Tilt Zoom (PTZ) camera
One composite device consists from fixed network camera and Zoom lens. The camera can be moved manually or automatically
PAN: move left and right
TILT: move up and down
Zoom: zoom in and zoom out according to the motion
You can view the sending image from the camera through the web browser but it is recommended to provide the camera with additional software for more options such as ability to store and manage the video
Note that the network camera connected to data switch through a UTP Cat 6 cable via RJ-45 Ethernet Interface so the system is monitored centrally over the Ethernet data network
5- Bandwidth
The bandwidth depends on the number of users and the image quality based on the design
Suppose that the camera will use 1500Kbps for 5 Frames per Second of the 320*240 image it is 1.5% of a 100Mbps
Note that the bandwidth calculation helps you to determine the approximate frame rate and the storage required base on the types of the camera and other factors