NVRs and IP Camera Technology

Posted by Daniel 06/30/2016 2 Comment(s)

A Network Video Recorder (NVR) with Internet Protocol (IP)-based cameras is a recent entry to the surveillance technology market. A NVR does not process or encode video feeds like a Digital Video Recorder (DVR). Instead, the NVR relies on the IP cameras to do that task which reduces the bandwidth needed on the network. The NVR uses IP based network protocols to receive the video feeds.  This can be on a Local area network or via the internet which greatly reduces the cables you need to run. An ordinary PC computer can be a NVR if it has the right kind of Video Management Software loaded on a Video Management Server. You can also buy a standalone proprietary device preconfigured with the software and hardware connections. This option limits your expandability to the number or connections and memory storage. The last option available for a NVR is to connect your IP cameras to a cloud service and then use your computer or mobile device to monitor the activity.

How you connect your IP cameras to the NVR will vary.

  • You can connect IP cameras to the NVR using Cat5 or Cat6 cables. Older IP cameras will need a separate power source, but newer Power over Ethernet cameras can get their power over the cable from the NVR.

  • As a non-wired alternative, some IP cameras can operate using Wi-Fi technology. This simplifies installation because you do not have to run cables between the NVR and IP camera. However, since the cameras have Wi-Fi and the video encoding software/hardware, they will cost more than other kinds of cameras. Wi-Fi also limits the range between the NVR and camera. Lastly, the cameras could be susceptible to hacking if not secured or can be jammed by a more power Wi-Fi signal transmitter.

IP cameras transmit in High Definition (HD) in either 720p or 1080p resolution. Older analog cameras can only transmit in standard definition (576i or 480i). When using an IP camera on a network, you will have to calculate how much bandwidth you will need. Bandwidth used depends on

  • The number of cameras

  • The cameras resolution (720p vs 1080p)

  • The frame rate (the number of frames per second)

  • If compression is used (for example H.264)

  • The amount of movement

  • The amount of light.

A standard frame rate is 30 frames a second and a MJPEG format frame is 30 Kbytes equalling 900 Kbytes a sec or 7200K bits a second. H.264 compression will reduce this by 20 times or reduce it to 360 Kbytes a second

NVRs provide digital recording and remote access. They can also provide additional video compression for remote viewing to reduce mobile cellular bandwidth consumption. There are hybrid NVRS that can accept both IP and non-IP cameras because they can process the raw video feed. This allows you to use your older camera and cable equipment.

IP cameras come in a wide variety of fixed lens, variable lens, pan/tilt/zoom, indoor and outdoor, and bullet and dome models. IP cameras will cost 2 to 3 times more than other HD format cameras. But since you may not need cabling, you can use the money saved for the more capable IP cameras.

2 Comment(s)

Lee wilson:
05/24/2018, 08:58:40 PM

I have 8 ch 4 mp nvr what other camera manufacturer will work on this nvr. Also do you have different mm lenses or varafocol camera at 4 mp

Virgil Brown:
08/30/2020, 09:46:34 PM

The above math appears to be off by a factor of 8. 7200K bits divided by 20 equals 360K bits not bytes, it would be 45K Bytes.

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