What effect does Bandwidth have on Digital Video?

Digital video is built from a series of still images that are recorded and played back at a rate that’s fast enough to make you think you’re are watching a moving image. Each individual image is called a frame. Video frame rates range from about 20 to 30 frames per second. Below that number, video motion seems jerky. Above that threshold, movement seems fluid and natural. The higher the frame rate, the more bandwidth your Smartphone requires.

A similar phenomenon occurs with camera resolution. Over the years, phone manufacturers have steadily increased the pixel count of the digital cameras they build into their products. As camera resolution increases, more and more data is being packed into each video frame. As a result, the bandwidth that’s necessary to successfully stream video to and from your Smartphone has also been rapidly increasing.

Sometimes however, the bandwidth that’s needed exceeds a Smartphone’s capacity to send or receive the required quantity of data in a timely manner. There are practical limits to the amount of data each wireless technology that’s built into your Smartphone can handle. For example, Bluetooth radios can handle between 1 million bits per second (Mbits/s) and 24 Mbits/s depending on which version of Bluetooth you use. Wi-Fi radios can handle between 1 Mbit/s and 150 Mbits/s depending on the Wi-Fi format used. Third Generation (3G) cell phone networks can handle between 384 kilobits per second (thousands of bits per second or Kbits/s) and 2 Mbit/s while 4G networks can handle between 100 Mbit/s and 1 gigabit per second (billions of bits per second or Gbit/s). To cope with these data flow restrictions, your Smartphone uses several compression schemes (aka file formats and transmission protocols) to squeeze the video signal into the available bandwidth without adversely affecting image quality. In addition, phone manufacturers install video cameras with frame rates and resolutions that match the bandwidth that’s available to them. That’s why some video can only be seen or sent with Wi-Fi technology while others can be streamed to and from your device using 3G or 4G broadband.