When it comes to networking for your video surveillance bandwidth is a key fundamental factor. Video surveillance can consume extremely large amounts of bandwidth, and each surveillance camera consumes different bandwidth loads differently.
What To Know
Bandwidth is normally measured in bits or bytes, 8 bits equals 1 byte. In other words, 40 Megabits per second and 5 Megabytes per second are the same amount. In written form, bits are represented with a lowercase ‘b’ and bytes as an uppercase ‘B’. As an example, 100Kb/s is eight times faster than 100KB/s. Similarly to vehicle speed, bandwidth is an average rate over time. Data rates are always measured as bits or bytes over a second. Similar to saying you were traveling at 60mph (or 96kph), you could also say a camera transmits 600 kilobits per second.
- Kilobits is a thousand, e.g., 100Kb/s is equal to 100,000b/s.
- Megabits is a million, e.g., 1Mb/s is equal to 1,000,000b/s.
- Gigabits is a billion, e.g., 1Gb/s is equal to 1,000,000,000b/s.
Typically, bandwidth is measured per camera, and the amount of bandwidth each camera needs varies greatly. To determine the total load of a network, simply add up the bandwidth needs of each camera. As an example, a network with 10 cameras with 3 of them using 4Mb/s, 4 using 2Mb/s, and 3 using 1Mb/s would have 23Mb/s of total network load for those 10 cameras.
Over time, a camera’s requirements for bandwidth to maintain a specific quality level can vary, sometimes considerably. As an example, an empty school hallway could require 1Mb/s for a camera on a Sunday afternoon, but 4Mb/s the following morning. It is important to understand the type of bit rate control used by a camera, as it has a large impact on bandwidth load.
- Constant bit rates (CBR), in which camera bit rates remain constant even when the scene changes.
- Variable bit rate (VBR), which adjusts bit rate to keep compression the same regardless of activity levels.
- Maximum bit rate (MBR), where the bit rate varies up to a set limit.
Affects bandwidth consumption:
- Frame rate
- Scene complexity
- Low light
There are two typical scenarios where video surveillance consumes network bandwidth:
- Camera or encoder to recorder: The production and recording of video usually occur on different devices. As an example, video could be captured by a camera, and recorded by a DVR / NVR / VMS server. During this process the video must be transmitted over the IP network, requiring bandwidth.
- Recorder to client: Clients tend to watch on devices that are not on the recorder’s network, requiring bandwidth to transmit the video.
Regardless of the type of camera, the proximity of the recorder to the camera significantly impacts bandwidth demands.
If you are looking to review security features for your business, like Bandwidth let RC Security help. Our continued research and partnerships with premium brands allow us to offer better quality every time.
About RC Security Consulting
RC Security Consulting protects the heart of Texas with design, installation, retrofit, repair, inspection, and monitoring of commercial security systems. We are centrally located in Collin County and provide service for almost 200 miles in all directions.