There are eight essential questions which have to be answered when you embark on your project of designing a video surveillance system. Here is an in-depth analysis meant for beginners, to understand the options and substitutes available to design a robust surveillance system.
The 8 essential questions which need to be sorted out are
1.) What type of surveillance cameras should be used?
2.) How to connect the cameras with the VMS?
3.) What type of video management system should be finalized?
4.) What type of video storage must be used?
5.) What type of video recording must be selected?
6.) Do I need Video Analytics?
7.) How to view and record the surveillance video?
8.) Do I need to integrate videos surveillance with access control systems?
1.) Surveillance cameras- Video Surveillance cameras are meant to be an essential component of a Video Surveillance System. In order to capture the right events in the right way, it becomes essential to deploy surveillance cameras in right and critical areas. The right place to deploy the surveillance cameras is where people or objects enter/exit, also known as chokepoints. Examples for chokepoints are doorways, hallways, driveways, corridors and gate ways. The deployment of cameras at entry/exit points will offer evidence on who entered the facility and at what time and date. In order to capture assets/objects, the cameras need to be deployed in areas where full view of objects/assets can be gained with clarity. For instance, placing cameras at the cash counter of a shopping mall will facilitate documentation of transactions taking place at the counter.
Once the area of deployment is confirmed then comes the turn of figuring out the right camera variant. Depending upon the application needs, a fixed or a PTZ camera can be selected. If the application need is simple monitoring of place or object then fixed camera can be the right option. With the present day advanced technology in place, clarity filled images/videos of the monitoring area can be easily gained. If the application need is to monitor moving objects/people then the need for PTZ camera arises. PTZ cameras facilitate panning, zooming and tilting of the camera to achieve wider fields of view. Usually, fixed cameras are almost 5-8 times less costly than PTZ cameras.
Color/ IR/ Thermal cameras- Depending upon the monitoring needs a camera with Infrared or thermal capabilities is selected. IR cameras use special lamps to make the image clear in zero light conditions, in order to capture an image. Thermal cameras are usually preferred for long range surveillance environments, where motion detection is sufficient. Obviously, if the application demands for color images, color surveillance cameras are preferred and prove beneficial in many instances. Like for instance, if a person wearing dark glasses and a red T-shirt has to be identified from among a crowd, a camera with color variant has the capability to do so. However, the deployment of colored cameras becomes suitable when the surveillance environment has well lit conditions.
Megapixel cameras or Standard Definition cameras- It’s like a similar situation where the choice has to be made between an LCD TV and a Smart TV. Obviously, both produce the same content under normal circumstances. But it is the clarity and picture quality which differentiates the two in the consumer’s world. Similarly, people used to use standard definition cameras for their surveillance needs. But now the technology is far more advanced and now users can choose high definition camera which facilitate clarity filled high definition images.
The other point which is important while selecting a surveillance camera is decision between IP and Analog technology. Presently, the on-going trend is to shift from analog cameras to IP cameras, as the later mode of surveillance brings in a bouquet of benefits. The intelligence to digitalize the image inside the network camera is making users shift to IP surveillance; where as Analog surveillance doesn’t serve this purpose.
Nowadays, in most surveillance environments a mix-up of surveillance camera types is seen in practice and moreover budget also plays a criterion in selection for analog or IP camera deployment.
2.) Connectivity- As discussed in earlier paragraphs, video can be transmitted over IP or as a native LAN network. However, most of the video feeds are being sent on IP network these days and so the craze for network cameras is increasing, as they can be directly connected to an IP network layout. In an analog system, cameras have to be first connected to a Digital Video Recorder and from that point then can be interfaced with the web. Yes, there is also an encoder option available for the analog cameras to connect to IP network.
Now, the situation arises on how to connect the cameras as captured videos. Irrespective of an IP or an Analog camera usage, the video feeds captured by these devices can be sent through cables or wires these days.
Sending videos via cable is still popular in most of the surveillance environments, as it offers highest point of security in doing so. Seventy percent of surveillance camera deployments are being made on cable layout. When the feasibility to lay cables becomes zero, then the option of using wireless transmission arises. But here, the chances of intercepting the signals and manipulating the videos can come up. Conversely with the latest technological advancements taking place in wireless transmission, the chance of signal interception is getting decreased.
3.) Video Management System- Video Management System is where all the intelligence of the surveillance system is contained. It acts as a hub, where functions such as acceptance of video from surveillance cameras, storing of the videos and managing the viewing for users, are resided. Video Management Systems has four themes to deal with and they are
- a.) Digital Video Recorders (DVRs)- Digital Video Recorders are devices which have software, hardware and storage capacity embedded in them. They accept analog camera feeds and also support remote viewing of videos over IP. DVRs can be installed in a simple way and still they have their own set of demand among the professional buyers.
- b.) Hybrid DVRs- Hybrid DVRs support recording/viewing of video feeds obtained from analog and IP cameras. Although, their main purpose is to support analog camera feeds, they can also serve IP camera feeds, if in case, the surveillance environment is filled with a mix-up of analog and IP cameras.
- c.) NVRs- Network Video Recorders accept video feeds from network cameras and in order to record videos from analog cameras, an encoder has to be used.
- d.) VMS- Video Management Software does not come with any hardware or storage attached to it and is in no way similar to a DVR/NVR. In order to obtain more freedom to manage the video feeds, video management software must be loaded onto a server. It gives the configuration ability to the administrator and offers a great set of control on managing the surveillance cameras.
4.) Video Storage- Mainly, surveillance videos are stored in order to retrieve and review them for future needs. The average storage duration is 30 days and is practiced globally. Depending on factors such as cost of storage and the value the stored video offers, the duration of the video storage is determined. Video Surveillance demands huge amount of storage and can reach up to 100s of TB in some cases. While going for the selection of surveillance storage, there are four options which are available.
- a.) Internal Storage- DVRs and NVRs are built with internal storage which varies from vendor to vendor.
- b.) Direct Attached Storage- When the storage media are located out of the DVR’s or NVRs or servers then they are called as Direct Attached Storage (DAS). They are connected and accessible through USB ports. An external hard drive is a good example of a DAS.
- c.) Network Storages such as NAS, SAN or IP SAN act as storage pools, accessible via IP network.
- d.) Onboard Camera Storage- Nowadays, surveillance cameras are being offered with onboard SD card support. So, cameras can record locally on-board, thus reducing network use and dependency.
5.) Video Recording- Recording a surveillance video to the video storage depends on factors such as recording resolution of the camera; whether it is done based on motion detection or on continuous basis and at what frame rate do the videos have to be recorded. Recording based on resolution and frame rates can influence the need for higher storage capacity of video storage to a large extent. Continuous recording will usually waste storage space and motion based recording has its own tradeoffs.
6.) Video Analytics- With the help of video analytics technology, scanning and analyzing of video feeds is possible. So, this action facilitates identification of threat or any kind of unfortunate event. Additionally, Video Analytics deployment on a Video Management System (VMS) also enables the intelligence of storing the videos based on the presence or absence of the motion.
7.) Viewing of captured video feeds- This can be done through local viewing, where video feeds are viewed from DVRs, NVRs or servers directly. Remote PC viewing is also effective as viewing of live and recorded videos through web applications is possible. Nowadays, mobile viewing through tablets, iPads and androids has become a technological fad. When hundreds and thousands of cameras are available in a surveillance environment, video wall viewing becomes practical. In this format, large screens are placed and a group of people keep an eye on the activities shown on the screen to respond to any urgent need of visual intelligence or video feeds.
8.)Integrating videos with other systems- Integration of video surveillance with other security operations is commonly seen in large organizations. Access control integration with video surveillance system is a common practice. However, budget plays a criterion in turning these options into reality.
Hope this serves as a basic guideline to beginners in IP surveillance field and gives them an overview of all the fundamental aspects of designing and deployment of an IP video surveillance system.