Edged based video recording is now the latest craze in IP Video Surveillance field, as it eliminates the troubles associated with network bottlenecks involved in centralized video recording systems. This article will shed some light on how the system of edge based recording works and what are the pros and cons associated with it.
How a Conventional Security Surveillance Design Works
In an IP surveillance environment, video recording takes place at Network Video Recorder (NVR) or centralized recording server. The video feed from the IP camera is pulled down by the server in a consistent manner and then it records the video onto the storage media. Usually, in order to utilize the storage resource to maximum, IP cameras are set to motion detection alert, where the videos are captured, only when a motion is detected and then the image is transferred to the storage. During this process, the server continuously streams the video feeds in search of any motion detection. As soon as the motion is detected, the video is captured and recorded.
The whole process is similar to that of an analog surveillance system; except for the fact that the whole process is carried out in more intellectual way in network video system.
Disadvantages of Centralized Recording System
In a network video approach the following problems are observed.
Bandwidth- A centralized network video approach is termed as a foe to network bandwidth. In a centralized camera approach, the stream is consistently pulled by the network cameras, regardless of recordings being carried out. The problem deteriorates when the network gets completely saturated.
Server Specification- Needless to say, a centralized server must be well capable to analyze the footage from the number of cameras. As the camera count increases, more bandwidth is required and more processing of video streams should be carried out. When all the network cameras start to communicate with the server at a time, there is a high probability of network bottleneck creation on low cost hardware, which reduces the effectiveness of the system.
Fault tolerance- When the camera control is being monitored by a centralized server, in the case the server goes down for some reason, video recording will not take place from there on. If in case the server gets damaged, there is a possibility of recordings getting lost. Although, this situation can be tackled with a failover server, additional costs on hardware and software will be cumbersome.
Here comes Edge Recording
Edge recording feature in an IP camera allows the recording functionality take place on the camera itself. IP cameras are now coming with edge based recording feature, where flash memory based SD/MicroSD memory cards are deployed on the network camera itself. The captured video can be later-on transferred to network storage or to a central server.
Edge recording benefits
As the recording takes place at camera level, there is no impact on network.
Since, motion detection feature is entertained at IP camera level, no footage is sent until motion is detected. As soon as the motion is detected, the network camera records the footage and will stop as the motion ends.
Ever since, the intelligence of processing and recording functionality is at camera level, the need for highly sophisticated storage drives has come down.
With in-built storage capacities of network cameras increasing from day to day, the need for recording server is getting less prominent. As soon as the camera loses network connectivity, it stores the captured footage to its on-board storage media and transfers it to the server when the connectivity gets restored.
Edge based recording disadvantages
As the surveillance storage is distributed on the network, managing the multiple storage locations becomes difficult. However, nowadays IP camera manufactures are coming up with intelligent monitoring feature of on-board storage, where footage monitoring throughout the network is made possible.
As the processing power of each camera is high, the cost of the device will be more than a normal IP surveillance camera.
ONVIF compliance is also hard to achieve as devices with this processing ability might not support devices from different manufactures for video exchange. If this feature is still achievable, then again the device may become too expensive.
Coming up with the best of both worlds
IP cameras are now being manufactured with the feature of Edge and centralized storage system. As mentioned in earlier paragraphs, whenever a network downtime occurs, the cameras record the footage to the camera and when the network is back, the footage is sent back to the centralized server. This approach will improve reliability as data loss will be nil, but still needs a centralized server causing data bottlenecks and increase of cost.
It seems like both sides of the argument are valid, as the advantage is that it reduces bandwidth demand and offers fault tolerance. At the same time, it eases management and also lower per-camera costs of centralized recording.
However, additional costs of both camera and storage devices, coupled with lack of support to ONVIF design structure may make Edge based recording an upcoming prospect of IP Video Surveillance. It is also a fact in reality that manufacturers of network cameras have already begun to focus on the Edge based surveillance and are coming up with varied, as well as improved products in coming days.