IP Cameras Explained

CCTV Overview

In an analog-based CCTV system the video image is transmitted over a coaxial cable to a digital video recorder. The DVR converts the analog video signal to a digital signal. Because an analog CCTV system transmits its video signal using coaxial cable it is only one way data communication method.

IP Camera Overview

Unlike the analog CCTV camera, with an IP camera the camera transmits the video signal in a digital format to a device called a network video recorder or NVR. The camera is a network device which means it has an IP address assigned to it.  It transmits its signal using an Ethernet category five wire; this is standard computer network cabling. With this method there is two way data communication.

CCTV versus IP Camera Resolution

One reason IP cameras are becoming very popular compared to analog CCTV cameras is that the IP camera transmits a very high resolution image to the NVR compared to a lower resolution image from the CCTV analog camera system. One advantage of an IP camera system is that you can use an existing computer network wiring infrastructure but the main reason is the higher resolution.

Processing Stored Images

When comparing the analog system to the Digital system both systems process their information at a centralized location. Whether it’s the digital video recorder or the network video recorder both systems have a Central video management software package installed. This manages things like video recording, alarm inputs or alarm conditions and then the storage of the images.

Types of IP Camera Systems

There is a variation of the IP camera whereby a specially designed IP camera stores the images on board the IP camera itself. With this IP camera the video information is processed right at the source and does not have to be transmitted down the network cabling wire. This means the camera packages the images into a file the same way an NVR would do except this time it’s processed right on board the camera. This IP camera stores the processed digital files and makes them ready for viewing on any type of storage device such as an Ethernet hard drive, removable flash disk, or a direct attached storage device. 

Advantages of a Standalone IP Camera

There are several advantages to this for example:

  1. You could direct connect an Ethernet external hard disk drive or a special storage unit and start recording terabytes, massive amounts of data getting high-resolution recording at the camera without using any of the network bandwidth.
  2. Then, using a standard web browser such as Internet Explorer or reviewing client users on the network can perform video sequence searches, day searches based on time and date, where the video is stored and play these directly back from the storage medium. In this scenario the only time bandwidth is used on the network is when stored images from the IP camera are viewed.
  3. You’re not able to do this on a central IP camera system because these images are processed at the IP Camera.
  4. When all of the images in a centrally-based IP camera system pass through the network it is a bottleneck waiting to happen. This can quickly cause network and server overload. When you have multiple cameras recording simultaneously in high-resolution video, the more cameras you have potentially the worst that will get. But, this is never a problem for decentralized IT camera systems.