Quick research about IP camera’s will tell you that the bandwidth used depends entirely on the camera type, codec used and frame rate for live video streaming. A quick search about codecs and camera differences revealed that IP cameras using a a codec with high compression and low frame rates will result in live streaming data rates of between 100 kBit/s and 350 kBit/s.
This means that is we take an average bandwidth of 200 kBit/s then the calculation for 1 hour of live video streaming / viewing will be:-
1 hour = 60 minutes = 3600s
3600s x 200 kBit/s = 720,000 kBits
720,000 kilobits = 703Mb (1 kilobit = 1024 Mb – Megabit)
So this is roughly 3/4 of 1Gb.
These are only estimates and you should contact your own camera or DVR manufacturer to determine how much bandwidth you will use for live streaming and for downloading images and videos. The 3G or 4G router does not determine how much data you would use – it is only providing the internet connection and does not determine how that connection is used.
Megabits, Megabytes, kilobits and kilobytes are often confused but as a simple rule of thume we use the following:-
Normally bandwidth speeds are measured in Mbs or Kbs (Megabits per second and Kilobits per second) – so in a speed test you might get a download speed of 20Mbps and an upload speed of 0.7Mbps (or 700 Kbps)
HDD Space is measured in KBs , MBs or GBs (Kilobytes, megabytes or Gigabytes)
If you don’t want to contact your IP Camera / DVR supplier to find out about their protocols and video standards then as a general rule of thumb a 90 minute film viewed in standard definition on Netflix uses about 2000MB / 2GB and if you view it in HD high definition this could be as high as 6GB.
The router is only using data if you remotely connect to your cameras / NVR and are viewing your live feeds or downloading or uploading data. If your camera or NVR is set to continuously upload the live feeds to an off site server then this will mean that your CCTV equipment will be using data all the time so you will need to find out from your CCTV equipment provider how much data this will use and then make your own calculations.