Network bandwidth and storage requirements are important considerations when designing a video surveillance system. The factors include the number of cameras, the image resolution used, the compression type and ratio, frame rates and scene complexity.
MPEG-4 calculation
Approx. bit rate / 8(bits in a byte) x 3600s = KB per hour / 1000 = MB per hour
MB per hour x hours of operation per day / 1000 = GB per day
GB per day x requested period of storage = Storage need
Note: The formula does not take into account the amount of motion, which is an important factor that can influence the size of storage required.
Motion JPEG calculation
Image size x frames per second x 3600s = Kilobyte (KB) per hour/1000 = Megabyte (MB) per hour
MB per hour x hours of operation per day / 1000 = Gigabyte (GB) per day
GB per day x requested period of storage = Storage need
Bandwidth and storage calculations
Network video products utilize network bandwidth and storage space based on their configuration. As mentioned earlier, this depends on the following:
- Number of cameras
- Whether recording will be continuous or event-based
- Number of hours per day the camera will be recording
- Frames per second
- Image resolution
- Video compression type: Motion JPEG, MPEG-4, H.264
- Scenery: Image complexity (e.g. gray wall or a forest), lighting conditions and amount of motion (office environment or crowded train stations)
- How long data must be stored
Bandwidth needs
In a small surveillance system involving 8 to 10 cameras, a basic 100-megabit (Mbit) network switch can be used without having to consider bandwidth limitations. Most companies can implement a surveillance system of this size using their existing network.
When implementing 10 or more cameras, the network load can be estimated using a few rules of thumb:
- A camera that is configured to deliver high-quality images at high frame rates will use approx. 2 to 3 Mbit/s of the available network bandwidth.
- With more than 12 to 15 cameras, consider using a switch with a gigabit backbone. If a gigabit-supporting switch is used, the server that runs the video management software should have a gigabit network adapter installed.
Technologies that enable the management of bandwidth consumption include the use of VLANs on a switched network, Quality of Service and event-based recordings.
Use our Video Surveillance Bandwidth and Storage Calculator to get certified solutions that meet your requirements.
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