1 The Analogue System

Consists of analogue camera(s), switcher/multiplexer device with direct link to the  monitor or TV

2 Upgrade : add network capability to analogue cameras

Video Servers

Consists of analogue camera(s), video server with monitoring now possible from multiple, remote locations.

Benefits

Remote access of images utilizing the computer network eliminating the need for dedicated security monitors in a central office
Password-protected access anywhere there is an Internet connection
Connect to a remote control station to view what is going on and control cameras and other aspects of the surveillance system
Ease of integration with other systems and applications
Lower TCO (total cost of ownership) by leveraging existing network infrastructure and legacy equipment
Creates a future-proof system No more complete system overhauls
 

3 Expand : add network cameras to a networked system

IP Cameras

Consists of networked system with option of adding as many IP cameras as required

Benefits

Viewing access can be restricted to only authorized persons, or live video can be posted on a company’s Web site for the entire world to see.
The necessary infrastructure already exists to add network cameras without high installation costs if the building is equipped with an IP network
Network cameras have greater functionality than analogue cameras and at a substantial cost saving.
Network cameras plug directly to the existing network, yielding substantial savings because the coaxial cabling required for analogue cameras isn’t needed.
No additional equipment is needed to view the video output from a network camera.
 

Factors to consider

At this point, we’ve seen that the transition from an existing analog system to a high-functioning digital IP-Surveillance system can be done step by step and in a cost-effective manner, but there are still a number of factors to consider. What about network bandwidth, bandwidth connections (network, xDSL, ISDN, cellular phone etc.), hard disk storage requirements and software?

Network Bandwidth
If you are using a local network, cameras can be patched through a special dedicated router for the camera, thus eliminating most concerns about bandwidth. However, if images are sent by PSTN, bandwidth considerations do come into play. To get a performance of 30 frames per second, you need a minimum bandwidth of 120 kB/s.

Hard disk space
Hard disk storage requirements are dependent on the frame rate of the video you want to store. If you want to store all video at 30 frames per second (30 fps) as opposed to 1 fps, then that requires 30 times the amount of storage. Each application has different recording and storage needs in terms video fps, and hard disk storage requirements will differ accordingly.

Software application
A wide variety of software applications can be used. What software to use is governed by the end-user application and their specific needs.