How Much Bandwidth Is Used by Online Security Cameras?
By Dave Maddox
Security cameras that connect directly to the Internet can generate data streams when they are being monitored or, in the case of cameras being recorded to a remote digital video recorder or cloud-based storage system, can consume network bandwidth on an ongoing basis. How much bandwidth is consumed depends on video quality, including color, resolution and compression. Several cameras streaming constantly can consume the full capacity of an Internet connection.
Security Video Bandwidth Factors
Traditional low-res security video has often been blurry and low quality, especially when captured as still photographs. In the transmission of video from standard-definition or high-definition cameras, one goal is to take advantage of the digital quality and preserve as much of the useful image as possible. Bandwidth requirements come from how much data needs to be transferred at "real time" rates to meet that requirement. Because of the special purpose of these image streams, specific adjustments and reductions can be made.
Image Quality and Compression
From satellite TV to home movie streaming services, video is often compressed to save bandwidth while still presenting an acceptable picture. Standard compression algorithms can be applied to IP camera video as well, resulting in significantly lower bandwidth consumption where required. Compromises introduced by compression can include unnatural motion or pixelation during motion, reduced colors, elimination of some detail, and loss of contrast. These may be acceptable compromises for reducing bandwidth and storage requirements.
Calculating Overall Bandwidth Requirements
The key factors in bandwidth requirements include the number of video sources, or cameras; the image resolution and number of frames per second; and the video compression standard in use, such as MPEG-4, H.264 or motion JPEG. In addition, image features such as background which are more easily compressed can reduce the bandwidth required. Using the calculator mentioned in Resources, three one-megapixel camera feeds at low quality and 7 frames per second or one-quarter of full speed would require 1.71Mbps, plus headroom on the connection for other network traffic, suggested by some vendors at 40% additional.
Remote Recording and Monitoring
Bandwidth requirements apply to any path the data takes, especially to remote monitoring or cloud storage locations. High-bandwidth camera systems could be especially expensive with real-time data over the Internet. Compression and other bandwidth-reduction techniques can result in significant cost savings for transmission and storage. If high-resolution, full-speed images are required, television transmission technologies and direct IP-based connections obtained from telecom providers might provide lower-cost options than straight public Internet bandwidth consumption.
Dave Maddox began journalism and article writing in 2005, after several decades of technical writing. His articles have appeared on a variety of websites, including Politics West by the "Denver Post." He has advanced training in electronics, computing and digital photography. Maddox studied literary theory and computer science at Harvard University.