- Resource Center
Power Over Ethernet Standards (PoE)
International Protection Rating Chart (IP66)
- 802.11 – This protocol specifies an over the air interface between a wireless client, more commonly a Wireless IP Camera, and a base station, or wireless router. This is the primary protocol used for communication by Wireless Local Area Network devices.
- Auto-Iris Lens – This type of lens is electronically controlled permitting the camera to maintain a consistent level of light throughout changing light conditions. These lenses are found on Day/Night Cameras.
- CCD Image Sensor – The Charged-Coupled Device Image Sensor begins as an analog device, which then converts small electrical charges into voltage, one pixel at a time. Additional equipment then digitizes these pixels. Neither CCD or CMOS is said to be superior to one another.
- CCTV – Closed Circuit Television, as opposed to open broadcast television, transmit signals to a specific place, with a limited number of monitors by way of video cameras. CCTV cameras may be used simply to monitor a specific area, or record events based certain rules, timeframes, and guidelines. CCTV systems encompass both Analog systems, and the newer IP Surveillance systems.
- CMOS – Complimentary Metal Oxide Semiconductor image sensors are similar to CCD, although these often include amplifiers, noise-correction, and digitized circuits. Neither CCD or CMOS is said to be superior to one another.
- CODEC – IP Video Codecs include MJPEG, MPEG, MPEG-2, and most recently H.264. These video Codecs use compressed algorithms to compress the data stream, ensuring good video quality, while greatly reducing the bit rates. This compression reduces bandwidth consumption allowing for multiple channels, and recently High Definition video streams to travel an IP Network without choking out other devices.
- DC Iris – Camera Iris that are motor driven, automatically adjustable opening that responds to changes in light.
- Digital PTZ - This type of PTZ allows users of the cameras to pan, tilt, or zoom into certain areas of the field of view, while the camera itself does not physically move. Typically requiring higher resolution cameras, a user can select an area of specific areas to monitor while still capturing the entire field of view. With digital PTZ, there are no moving parts that may jam or wear out over time. Axis Communications states it best in their Guide to Network Video, "A non-mechanical PTZ camera uses a megapixel image sensor and allows an operator to instantly zoom in on any part of a scene without any loss in image resolution. This is achieved by presenting an overview image in VGA resolution (640x480 pixels) even though the camera captures a much higher resolution image. When the camera is instructed to zoom in on any part of the overview image, the camera uses the original megapixel resolution to provide a full 1:1 ratio in VGA resolution. The resulting close-up image offers good details with maintained sharpness. With a normal digital zoom, the zoomed-in image often loses detail and sharpness"
- DVR – A Digital Video Recorder, designed for Video Surveillance, utilizes hard drives to record and monitor video streams from surveillance cameras. These devices can reside on an IP Network, and can be accessed from the internet, but differ greatly from a Network Video Recorder, or NVR. DVR’s are typically used for Analog Surveillance Systems, whereas NVR are used for IP Surveillance systems.
- Ethernet – This is the primary technology used for Local Area Networks. This technology uses a combination of mediums to connect devices to a network, and pass data between these devices from low to very high speeds.
- Field of View – Also called the field of vision, is the extent of view a camera can see at any given moment. The field of view can be modified by the use of various angled lenses, or may also expand with the use of Pan/Tilt/Zoom cameras.
- FPS - Frames Per Second, also called Frame Rate, or Frame Frequency, is the rate at which a camera can produce unique, consecutive images. These individual images are considered frames, and are measured in the amount that can be produced in a given second. Newer IP Surveillance cameras can produce a great number of frames per second, at a high resolution (30fps, at 1080p HD resolution).
- FTP – File Transfer Protocol is a standard network protocol that is used to copy files from one host to another, over the internet. This technology enables a client to log into a host, such as an NVR, and copy over surveillance footage.
- H.264 – Also known as MPEG-4 Part 10, is one of latest and most efficient standards for video compression in IP Video Surveillance. This compression format can provide good video quality at a significantly lower bit rate level than previous standards, This will allow more data intense video streams such as High Definition to transmit across a network without choking out bandwidth from other devices.
- HD – High Definition is increasingly becoming a popular feature in Surveillance Cameras. Cameras that view and record in 720p(1280x720) or 1080p(1920x1080) are said to have HD resolution. Cameras that are also rated as Megapixel Cameras can obtain HD resolution.
- HTTP – Hypertext Transfer Protocol is the primary protocol used for client-server computing. The protocol is essentially a set of rules for transferring files, and video over the World Wide Web. HTTP is an application protocol that runs on top of the TCP/IP suite of protocols, that are the foundation of the internet.
- Hybrid – Hybrid Video Recorders utilize the functionality of both a DVR and NVR allowing connectivity to Analog and IP Cameras. Hybrid Servers allow older Analog systems to cost effectively expand into the IP Surveillance realm without having to completely overhaul and replace every device.
- Image Compression – This is the act of compressing digital images to be able to store and transmit this data in a more efficient form. Most common formats in Video Surveillance are JPEG, MJPEG, and H.264 (also known as MPEG-4). Currently the most efficient format is H.264.
- JPEG – A compression format most commonly used for photographs, and digital point and shoot cameras. One of the first of many compression formats, it is commonly used in lower end Surveillance Cameras, for higher frames per second on higher end cameras. With features of HD resolution at 30fps utilizing H.264, JPEG may soon be phased out.
- IP - Internet Protocol is a protocol, or set of rules, used for communicating data across a packet-switched internetwork. These types networks are based of the Internet Protocol Suite, or the TCP/IP model. The Internet Protocol is the core component of an IP Video Surveillance system. IP Surveillance differs from Analog systems, in that the data that produced by Analog device travel across Coaxial cable, as opposed to Twisted Pair networking cable (Cat-5, Cat-5e, or Cat-6 cable).
- IP Address – A numerical label that is assigned to a device residing on a computer network. IP Cameras would have an IP address assigned to them as this is how they are identified on an IP System.
- IP Camera – A Surveillance Camera that utilizes an Ethernet link, network cables as opposed to Coaxial cable, and RJ-45 connectors that connect to a port on an IP networked recorder, switch, or hub.
- IP66 Rating – International rating given to electronic devices that have complete protection from dust, and water projected at jet-like power. Cameras with the IP66 rating are said to be “Outdoor Ready”
- IR Illuminators - Infrared Illuminators project light at the infrared electromagnetic spectrum, which is below visible range for the human eye. Cameras with infrared illuminators are said to be Day/Night Cameras, as the camera is still able to produce a good quality picture, but in black and white.
- LAN – A Local Area Network is a local computer network established for communication between computers, or IP designed devices.
- Lux – A measurable unit of illumination equal to 1 lumen per square meter. 1 lumen is equal to 0.0929 foot candle.
- Megapixel – A Megapixel is equal one million pixels. This is used as a unit of resolution of digital cameras.
- Motion Detection – A cameras ability to detect motion within its field of views. Some cameras have motion detection features that initiate recording only when motion is detected, therefore reducing the amount of video recorded, saving disk space.
- MJPEG – A class of video codec format that superseded JPEG. Very similar to JPEG, but is based on the Discrete Cosine Transform. This compression format has been eclipsed by the more efficient H.264.
- MPEG4 – More commonly known as H.264, which the latest compression format available for reducing bandwidth consumption, and the bit rate level than previous codecs.
- Network Camera – Used interchangeably with IP Camera, a Network Camera is a surveillance camera that utilizes the Internet Protocol for transmitting data across a TCP/IP based network. Network Cameras utilize a Network Video Recorder, twisted pair cables, and RJ-45 connectors, as opposed to the DVR, Co-ax cable, and BNC connectors that Analog systems use.
- NVR – Network Video Recorder are most commonly used in IP based Surveillance Systems. NVRs differ from DVRs in that they do not used Co-Axial cable, or BNC connections. NVRs typically reside on a computer based network, with it device all being IP, computer based devices.
- NTSC – Named for the National Television System Committee, which the television broadcast standard in the US among other countries.
- Pan – The side to side movement of a PTZ Camera
- PAL – Phase Alternate Line is a television standard used most commonly in Europe, as opposed to NTSC used in the United States.
- P-Iris – A type of Lens developed by Axis Communications deemed to have precise iris control, and it is said to supercede the Auto, or DC iris. Axis claims this new iris will improve contrast, clarity, resolution and depth of field.
- PoE - Power Over Ethernet refers to use the standard IEEE 802.3af which allows the use of power at data to travel simultaneously over one Ethernet cable. IP Cameras that are PoE capable only require a PoE Capable switch, or a power injector to power the camera.
- PTZ – Pan/Tilt/Zoom is the mechanical feature of PTZ enabled camera which allows you to pan from side to side, tilt up and down, and zoom into an object within the field of view.
- Resolution – Refers to distinct pixels in each dimension that can be displayed.
- SD Memory Card – A non-volatile memory card format intended for portable devices. IP Cameras are increasingly making internal storage available via an SD Card reader.
- SVGA – Super Video Graphics Array normally referred to the 800x600 pixel resolution.
- Tilt – The up and down movement of a PTZ Camera
- Video Server – A computer based device that is intended host, or record video by way of hard disk drives.
- VGA – Video Graphics Array is the most prolific and connection standard available. VGA resolution can go up to 640x480 pixels.
- Wide Dynamic Range – A technology and feature of surveillance cameras best utilized when there circumstance of great variations of light. This feature is best noticed when the field of view has excessive areas of light and dark, working to balance out the intensities, and provide a clear image.
- Wireless Network Camera – This a Network, or IP Camera that utilizes WLAN, or Wireless Local Area Network technology. These cameras communicate by way of the 802.11 Internet Protocol. Although these cameras aren’t as reliable as hard wired cameras, they are increasingly becoming refined, and more popular.
- Zoom – A Function of a PTZ Camera which reduces the field of view, and increases the resolution of the area of which one is “zooming” into.
Power Over Ethernet Ratings
|0||Default||0 - 4||0.44 - 12.94||Classification unimplemented|
|1||Optional||9 - 12||0.44 - 3.84||Very Low power|
|2||Optional||17 - 20||3.84 - 6.49||Low power|
|3||Optional||26 - 30||6.49 - 12.95||Mid power|
|4||Reserved||36 - 44||12.95 - 25.50||High power|