Most organizations will mix and match a number of different camera types. For instance, an organization may use infrared fixed analog cameras around a perimeter with an analog PTZ overlooking the parking lot. Â On the inside, they may have a fixed megapixel camera covering the warehouse and a number of fixed IP cameras covering the entrance and hallways.
In professional video surveillance, cameras are almost always connected to video management systems for the puprose of recording and managing access to video. Â There are two main characteristics to decide on for connectivity.
- IP vs. Analog: Video can be transmitted over your computer network (IP) or it can be sent as native analog video. Today, most video feeds are sent using analog but migration to IP transmission is rapidly occuring. Both IP cameras and analog cameras can be transmitted over IP. Â IP cameras can connect directly to an IP network (just like your PC). Analog cameras cannot directly connect to an IP network. However, you can install an encoder to transmit analog feeds over IP. The encoder has an input for an analog camera video feed and outputs a digital stream for transmission over an IP network. Learn more about the choice between IP and analog transmission.
- Wired vs Wireless: Video can be sent over cables or though the air, whether you are using IP or analog video. Over 90% of video is sent over cables as this is generally the cheapest and most reliable way of sending video. However, wireless is an important option for transmitting video as deploying wires can be cost-prohibitive for certain applications such as parking lots, fence lines and remote buildings. Learn more about when and how to use wireless video surveillance.
3. Video Management System
Video management systems are the hub of video surveillance solutions, accepting video from cameras, storing the video and managing distribution of video to viewers.
There are 4 fundamental options in video management systems. Most organizations choose 1 of the 4. However, as companies may have multiple types when they transition between one and another.
- DVRs are purpose built computers that combine software, hardware and video storage all in one. By definition, they only accept analog camera feeds. Almost all DVRs today support remote viewing over the Internet. Â DVRs are very simple to install but they significantly limit your flexibility in expansion and hardware changes. DVRs are still today the most common option amongst professional buyers. However, DVRs have definitely fallen out of favor and the trend is to move to one of the 3 categories below.
- HDVRs or hybrid DVRs are DVRs that support IP cameras. They have all the functionality of a DVR listed above plus they add support for IP and megapixel cameras. Most DVRs can be software upgraded to become HDVRs. Such upgrades are certainly a significant trend and is attractive because of the low migration cost (supports analog and IP cameras directly). Â Learn more about the value and issues in selecting HDVRS.
- NVRs are like DVRs in all ways except for camera support. Whereas a DVR only supports analog cameras, an NVR only supports IP cameras. To support analog cameras with an NVR, an encoder must be used.
- IP Video Surveillance SoftwareÂ is a software application, like Word or Excel. Unlike DVRs or NVRs, IP Video Surveillance Software does not come with any hardware or storage. The user must load and set up the PC/Server for the software. This provides much greater freedom and potentially lower cost than using DVR/NVR appliances. However, it comes with significant more complexity and time to set up and optimize the system. Â IP Video Surveillance Software is the hottest trend in video management systems currently and is the most frequent choice for very large camera counts (hundreds or more). Learn more about choosing software only video surveillance.
Surveillance video is almost always stored for later retrieval and review. The average storage duration is between 30 and 90 days. However, a small percentage of organization store video for much shorter (7 days) or for much longer (some for a few years).
The two most important drivers for determining storage duration is the cost of storage and the security threats an organization faces.