CCTV Glossary – www.CCTV.supplies

10/100 Base-T

IEEE-802.3 specification for 10 or 100Mbps Ethernet.

Power over Ethernet or PoE describes any of several standardized or ad-hoc systems which pass electrical power along with data on Ethernet cabling. This allows a single cable to provide both data connection and electrical power to devices such as wireless access points or IP cameras. Power may be carried on the same conductors as the data, or it may be carried on dedicated conductors in the same cable.

IEEE802.3af (15.4W per Port): The current IEEE802.3af standard for Power-over-Ethernet was formally approved in 2003, defining PoE applications requiring up to 12.95W of power. Phihong’s selection of IEEE802.3af Power-over-Ethernet midspans and splitters allow users to bring power and data to an array of devices without the expense of hiring an electrician to bring power to additional locations. Should the device that needs power such as a camera or VoIP phone not be PoE compatible, there are splitters available to separate the power and data while still eliminating the need for and expense of AC power outlets.

IEEE802.3at PoE Plus (30W per Port): POE Plus as ratified in September 2009 defines Power-over-Ethernet applications up to 25.5W per port of power. As a founding member of the IEEE task force dedicated to the development of this standard, Phihong is able to deliver a complete range of fully compliant Midspans with the most selection available on today’s marketplace. Applications include; wireless multi-radio access points, Pan Tilt Zoom security cameras with heaters, 802.11n wireless applications and IP phones with streaming video displays

Ultra PoE (60W per Port): This category though not defined by IEEE, it works within all of the safety parameters as defined for the IEEE802.3at standard. Ultra PoE has an output power of 60W to 80W per port and is designed for a much more diverse array of applications. More common applications can be found in use with computer workstations, LCD display panels, WAP arrays and complex POS systems.

Mega PoE (95W per Port): The newest addition to the Phihong PoE family is a massive 95W per port series of midspans. Phihong is the first to offer this much power combined with data over a single Ethernet cable. This new series has a large array of specialized applications that it can be used for including Kiosks, Magnetic Locks, Computer Workstations and numerous security functions including access and lighting. Though 95W is a lot of power, it still complies with UL’s Safety Extra Low Voltage specifications and all safety measures as outlined in the IEEE802.3at standard.

AAC

Advanced Alarm Control: A flexible and sophisticated alarm management subsystem that allows rules to be created that define which input(s) activate one or more outputs. In its most basic form, a rule could define which input(s) should activate which output(s). In a more complex form, a rule can be programmed to take a specific keyboard command (pre-existing or not) and perform a dome function, or any combination of the above.

ActiveX

ActiveX is a standard that enables software components to interact with one another in a networked environment, regardless of the language(s) used to create them. Web browsers may come into contact with ActiveX controls, ActiveX documents, and ActiveX scripts. ActiveX controls are often downloaded and installed automatically as required.

Address

Each unit has a numerical address in a control system in which it is located. This allows the appropriate unit to be referenced and operated with.

AF

Auto-Focus system by which the camera lens automatically focuses on a selected part of the subject.

AGC

Automatic Gain Control: The electronics that regulate the gain or amplification of the video signal. In practice image will brighten as gain is increased.

Angle

The field of view, relative to a standard lens in a 35mm still camera, expressed in degrees, e.g. 30°. For practical purposes, this is the area that a lens can cover, where the angle of view is determined by the focal length of the lens. A wide-angle lens has a short focal length and covers a wider angle of view than standard or telephoto lenses, which have longer focal lengths.

Aperture

The size of the opening in the iris, which controls the amount of light that reaches the Sensor. The larger the F-Stop number, the less light reaches the sensor. Ex: F1.2 lens can capture more light than an F3.5 lens.

ARP

Address Resolution Protocol: A protocol for mapping MAC and IP addresses. A request is broadcast on the local network to discover the MAC address for an IP address.

ASIC

Application Specific Integrated Circuit: A circuit designed for a specific application, as opposed to a general purpose circuit, such as a microprocessor.

Aspect ratio

A ratio of width to height in images. A common aspect ratio used for television screens and computer monitors is 4:3. High-definition television (HDTV) uses an aspect ratio of 16:9.

Auto Dome

Fully integrated, high speed, pan/tilt/zoom camera built into a protective dome housing allowing full and continuous 360° coverage of the scene.

Auto-Black

A technique of boosting the video signal level to produce a full amplitude video signal, even when the scene contrast is less than full range (glare, fog, mist, etc.). The darkest part of the signal is set to black and the lightest part to white, thus increasing the contrast.

Auto-Focus

The lens continuously adjusts to the correct focus automatically for the sharpest picture.

Auto-Iris

This special type of iris is electrically controlled by the camera, to automatically regulate the amount of light allowed to enter.

Auto-Pan

The camera pans continuously between right and left limit settings.

Auto-Pivot

As the camera tilts through the vertical position, the camera rotates to maintain the correct orientation of the image.

Auto-Scaling

As the camera zooms in to increase the size of objects on the monitor screen, the pan and tilt speeds are reduced so that the relative speed on the screen remains constant for similar joystick control positions.

Auto-Track

A patented technology that integrates motion detection into the camera allowing tracking of an object and zooming in to optimize size and perspective

AVI

Audio Video Interleave: A video format that supports simultaneous playback of audio and video.

AWB

Auto White Balance: A feature that allows a color camera to automatically adjust its output color to give a natural color, independent of the lighting used.

Balun

Short for Balance/Unbalanced; often referred to as a CCTV transceiver. A device that converts a balanced video signal (e.g. as used on twisted pair) line to an unbalanced signal (e.g. as used on coax). In a balanced line both wires are electrically equal. In an unbalanced line one wire has different electrical properties than the other.

Baud

Unit of measure for the speed of data transmission

Bilinx

A communications protocol that allows remote control, configuration, and updates to be performed over the video cable (Coax or Passive UTP).

Bilinx Address

The address may be set locally using the Bilinx Configuration Tool for Imaging Devices (CTFID) or remotely using the Fast Address function (see Fast Address).

Biphase

Pan/Tilt/Zoom protocol for Bosch products.

Bit rate

The bit rate (in kbit/s or Mbit/s) is often referred to as speed, but actually defines the number of bits/time unit and not distance/time unit.

Bit/s

Bits per second, the actual data rate.

Bitmap

A bitmap is a data file representing a rectangular grid of pixels. It defines a display space and color for each pixel (or “bit”) in the display space. This type of image is known as a “raster graphic.” GIF’s and JPEG’s are examples of image file types that contain bitmaps. Because a bitmap uses this fixed raster method, it cannot easily be rescaled without losing definition. Conversely, a vector graphic image uses geometrical shapes to represent the image, and can thus be quickly rescaled.

BLC

Back Light Compensation: Selectively amplifies parts of the image to compensate for large contrast differences when only a portion of the image is brightly lit (e.g. a person in a sunlit doorway).

Bluetooth

Bluetooth is an open standard for wireless transmission of voice and data between mobile devices (PCs, handheld computers, telephones and printers).

Bonjour

Also known as zero-configuration networking, Bonjour enables automatic discovery of computers, devices, and services on IP networks. Bonjour allows devices to automatically discover each other without the need to enter IP addresses or configure DNS servers. Bonjour is developed by Apple Computer Inc.

BOOTP

Bootstrap Protocol: A protocol that can automatically configure a network device (give it an IP address). BOOTP is the basis for a more advanced network management protocol, the Dynamic Host Configuration Protocol (DHCP).

Broadband

In network engineering terms, this describes transmission methods where two or more signals share the same carrier. In more popular terminology, broadband is taken to mean high-speed data transmission.

Cable Category

Application and bandwidth rating system for UTP cabling. Categories 1 through 7 are based on EIA/TIA-568-B standards. Category is typically abbreviated CAT. UTP Category 5, 5e, 6, and 7 are used for Ethernet data cabling applications. Standard Ethernet wiring distances are limited to a maximum of 100 m (328 ft.) when using UTP wiring.

Cable Compensation

A technology that prevents image degradation caused by signal losses when transmitting video over long cable lengths.

CCD

Charged Coupled Device: A type of solid state image sensor used in CCTV cameras. The sensor converts light energy into electrical signals.

CCD Format

Indicates the size of the camera sensor used. In general, the larger the sensor, the more sensitive the camera and the better the image quality. Its size is measured diagonally and can be 1/4″, 1/3″, 1/2″ or 2/3″.

CCTV

Closed Circuit TeleVision: A video system that transmits television signals over a closed (nonbroadcast) system.

CF

CompactFlash: Digital storage media – used in computers, cameras, and digital assistants in the form of CF cards

CGI

Common Gateway Interface: A specification for communication between a web server and other (CGI) programs. For example, a HTML page that contains a form might use a CGI program to process the form data once it is submitted.

CIF

Common Intermediate Format: Video format with 352 × 288/240 pixels

Client / Server

Client / server describes the relationship between two computer programs in which one program, the client, makes a service request from another program, the server, which fulfills the request. Typically, multiple client programs share the services of a common server program. A web browser is a client program that requests services (the sending of web pages or files) from a web server.

CMOS

A CMOS is a widely used type of semiconductor that uses both negative and positive circuits. Since only one of the circuit types is on at any given time, CMOS chips require less power than chips using just one type of transistor. CMOS image sensors also allow processing circuits to be included on the same chip, an advantage not possible with CCD sensors, which are also much more expensive to produce.

Coaxial Cable

Coaxial cable is the standard means of transmitting analog video in a CCTV system. Coaxial is also used by cable companies to distribute television in residential buildings.

Codec

In communications engineering, a codec is usually a coder/decoder. Codecs are used in integrated circuits or chips that convert e.g. analog video and audio signals into a digital format for transmission. The codec also converts received digital signals back into analog format. A codec uses analog-to-digital conversion and digital-to-analog conversion in the same chip.

Codec can also mean compression/decompression, in which case it is generally taken to mean an algorithm or computer program for reducing the size of large files and programs.

Color Temperature

A measure of the relative color of illumination. Generally used to specify the color balance correction of a camera to achieve a natural color image.

The term used in general illumination is correlated color temperature (CCT). CCT relates to the color of light produced by a light source, and uses the Kelvin temperature measurement scale (SI unit of absolute temperature). It describes the relative color appearance of a white light source, indicating whether it appears more yellow/gold (“warm”) or more blue (“cool”), in terms of the range of available shades of white.

Many people are now familiar with the idea of a “warm” white or a “cool” white being offered by fluorescent and other light bulbs. These bulbs have vastly different color temperatures. The “warm” bulb often has a color temperature of 3,000K and casts a more orange/red light on objects. Because you normally associate warmth with red or orange objects, this accounts for the “warm” descriptive name, even though it is a cooler (lower) temperature on the Kelvin scale. A “cool” white bulb commonly has a color temperature of 4,100K and higher on the Kelvin scale. This is in the low range of blue color, similar to ice, therefore earning the “cool” description.

Composite Video

A type of video signal in which the red, blue and green signals (sometimes audio signals too) are mixed together.

Compression

Image compression minimizes the file size (in bytes) of an image. Two of the most common compressed image formats are JPEG and GIF. Video compression uses modern coding techniques to reduce redundancy in video data. Most video compression algorithms and codecs combine spatial image compression and temporal motion compensation. Video compression is a practical implementation of source coding in information theory. In practice, most video codecs also use audio compression techniques in parallel to compress the separate, but combined data streams as one packageYear – Standard – Publisher – Popular Implementations: 1984 – H.120 1988 – H.261 – ITU-T – Videoconferencing, video telephony 1993 – MPEG-1 Part 2 – ISO, IEC – Video-CD 1995 – H.262/MPEG-2 Part 2 – ISO, IEC, ITU-T – DVD Video, Blu-ray, Digital Video Broadcasting, SVCD 1996 – H.263 – ITU-T – Videoconferencing, video telephony, video on mobile phones (3GP) 1999 – MPEG-4 Part 2 – ISO, IEC – Video on Internet (DivX, Xvid …) 2003 – H.264/MPEG-4 AVC – Sony, Panasonic, Samsung, ISO, IEC, ITU-T – Blu-ray, HD DVD, Digital Video Broadcasting, iPod Video, Apple TV, videoconferencing 2009 – VC-2 (Dirac) – SMPTE – Video on Internet, HDTV broadcast, UHDTV 2013 – H.265 – ISO, IEC, ITU-T – Video on Internet, HDTV broadcast, UHDTV, Ultra HD CCTV

Contrast

Defines the degree of difference between the lightest and darkest parts of an image or video stream.

Control unit

If a CCTV system has more than one camera, there must be a way to control the video signals going to recorders and monitors. There are three basic types of Video Control Unit: Multiplexer, Switch and Quad.

CTFID

Configuration Tool for Imaging Devices: Bosch software used to configure and update cameras and other remote devices over video cable using Bilinx, and to save them for later use.

CVBS

Composite Video Blanking and Sync: The format of an analog television (picture only) signal before it is combined with a sound signal and modulated onto an RF carrier. Composite video is often designated by the CVBS acronym, meaning any of Color, Video, Blank, and Sync, Composite Video Baseband Signal, Composite Video Burst Signal, or Composite Video with Burst and Sync. It is usually in a standard format such as NTSC, PAL, or SECAM.

Day/Night (IR Sensitive)

A camera that has normal color operation in situations where there is sufficient illumination (day conditions), but where the sensitivity can be increased when there is little light available (night conditions). This is achieved by removing the infrared cut filter required for good color rendition. The sensitivity can be further enhanced by integrating a number of frames to improve the signal-to-noise ratio of the camera.

DC-Iris

This special type of iris is electrically controlled by the camera, to automatically regulate the amount of light allowed to enter.

De-interlacing

Interlaced video is video captured at 50 pictures (known as fields) per second, of which every 2 consecutive fields (at half height) are then combined into 1 frame. Interlacing was developed many years ago for the analog TV world and is still used widely today. It provides good results when viewing motion in standard TV pictures, although there is always some degree of distortion in the image.

To view interlaced video on e.g. a computer monitor, the video must first be de-interlaced, to produce progressive video, which consists of complete images, one after the other, at 25 frames per second. See also Progressive scan.

Decoder

A video decoder is an electronic circuit, often contained within a single integrated circuit chip, that converts base-band analog video signals to digital components video.

Default Shutter

A feature allowing the shutter speed to be set to a fast speed to eliminate motion blur and provide a detailed and clear image of fast-moving objects while there is sufficient light. When light levels fall and other adjustments have been exhausted, the shutter speed reverts to the standard setting to maintain sensitivity.

DHCP

Enables dynamic distribution of the network configuration parameters, Hence eliminates use of manual configuration. It operates on basis of client server model.

DHCP

Dynamic Host Configuration Protocol: Uses an appropriate server to enable dynamic assignment of an IP address and other configuration parameters to computers on a network (Internet or LAN).

A DHCP enabled router will auto-assign a CCTV camera or DVR an appropriate IP address when DHCP is enabled. However a specific IP address should be assigned to the camera or DVR that is outside the router’s DHCP range to ensure IP address of equipment remains constant and does not change (for example after router power loss).

DHCP is useful for initial setup to determine the appropriate IP address subnet for the network.

Digital Image Stabilization

An algorithm that virtually eliminates camera shake in both the vertical and horizontal axes, resulting in exceptional image clarity.

DNR

Dynamic Noise Reduction: A digital video processing technique that measures the noise (image artifacts) in the picture and automatically reduces it.

DNS

Domain Name System: A service that stores domain names and translates them into Internet Protocol (IP) addresses.

A common public DNS is Google at 8.8.8.8 and 8.8.4.4.

Domain server

The domain server is the server that authenticates the users on the network. Domains can be used by organizations that wish to centralize the management of their (Windows) computers. Each user within a domain has an account that usually allows them to log in to and use any computer in the domain, although restrictions may also apply.

Dual-Stream

Dual-stream technology adopts one channel (main-stream) to deliver high definition video for local HD video recording/storage, such as 5 megapixel, 3 megapixel, 2 megapixel (1080p), 1.3 megapixel (720p), and a second channel (sub-stream) to deliver low or standard definition video over Internet for remotely surveillance (e.g. viewing cameras on a smartphone). Dual-stream technology enabled video surveillance products deliver high definition video for local video storage, meanwhile overcomes 3G/ADSL network bandwidth limitation to deliver smooth low/standard definition video.

Main-stream: stream resolution is higher than sub-stream, for local video streaming, output high definition video to display on the local monitor, or record HD video on your local network video recorder (NVR). Currently, the main-stream resolution are 2560×1920 (5 megapixel), 2048×1536 (3 megapixel) 1920×1080 (1080p) and 1280×720 (720p). Main-stream delivers real-time (30fps or even high frame rate 60fps) HD video stream to ensure local recording offers detailed information without missing anything important.

Sub-stream: offering low/standard definition video primarily for lower bandwidth situations. The sub-stream resolution are QCIF, CIF, 2CIF, DCIF, 4CIF (D1). Majority video surveillance products can automatically choose appropriate sub-stream resolution to match your smartphone’s display resolution. Sub-stream can transmit key frames and sub-frames to deliver video, which can decrease the network bandwidth burden and “smooth” the video in low bandwidth situations.

Duplex

Term used to define the direction of data transmission between two parties. Half-duplex allows data transmission in both directions but not simultaneously. Full-duplex allows simultaneous data transmission.

Encoder

Video encoders, also known as video servers, enable an existing analog CCTV video surveillance system to be integrated with a network video system. Video encoders play a significant role in installations where many analog cameras are to be maintained.

A video encoder makes it possible for an analog CCTV system to migrate to a network video system. It enables users to gain the benefits of network video without having to discard existing analog equipment such as analog CCTV cameras and coaxial cabling.

A video encoder connects to an analog video camera via a coaxial cable and converts analog video signals into digital video streams that are then sent over a wired or wireless IP-based network (e.g., LAN, WLAN or Internet). To view and/or record the digital video, computer monitors and PCs can be used instead of DVRs or VCRs and analog monitors.

Ethernet

The most commonly used local area network (LAN) access method. Ethernet complies with the IEEE 802.3 standard. The Ethernet standard supports 10 Mbps, 100 Mbps, 1000 Mbps, and 10 Gb (Gigabit) data transmission rates.

ETRAX

Ethernet Token Ring AXIS: The ETRAX chip is the cornerstone of Axis technology and the ‘brain’ in nearly all Axis products. A multipurpose Linux chip with integrated Ethernet networking and extremely flexible I/O options.

F-Number

The standard measure of the lens aperture, which is the iris diameter, divided by the focal length of the lens. The lower the maximum aperture (F-Number or F-Stop), the more light that passes through the lens.

F-Stop

Factory Default Settings

These are the settings that originally applied for a device when it was first delivered from the factory. If it should become necessary to reset a device to its factory default settings, this will, for many devices, completely reset any settings that were changed by the user.

Fast Address

A system for setting the address of the camera remotely from the control system.

Fiber Optic Transmission

Refers to the transmission of video and data via optical fibers. Optical fibers are thin glass strands that are designed for light wave transmission. Video and data are digitized and transformed into a series of light pulses. There are two primary types of optical fiber; singlemode and multimode. Singlemode fiber is used when large distances must be spanned, typically greater than 2 Km/1.2 miles (see Singlemode). Multimode is typically used to span smaller distances such as the inside of buildings or on small campuses (see Multimode).

Field of View

The measure of the visible area within the camera’s field of view. The larger the focal length, the smaller the field of view. The smaller the focal length, the wider the field of view.

Firewall

A firewall works as a barrier between networks, e.g. between a Local Area Network and the Internet. The firewall ensures that only authorized users are allowed to access the one network from the other. A firewall can be software running on a computer, or it can be a standalone hardware device.

Fixed iris

With fixed iris lenses, the iris opening cannot be adjusted and is fixed at a certain f-number. The camera can compensate for changes in the level of light by adjusting the exposure time or using gain.

Fixed Lens

Fixed focus lenses are the simplest type of Lens, and therefore the cheapest. The presets focal length means a precise calculation is required to select the Lens most suitable for the location, based on the desired size of viewing area and its distance from the Camera. Typical Lens sizes offer either 30 degree view – narrow to allow more detail at distance – or 60 degree, which offers a much wider angle of view.

Varifocal lenses offer more flexibility, allowing the field of view to be adjusted manually. Although more expensive these lenses of popular because the use it is able to get the view required rather than the limited by the constraints of the fixed Lens.

Finally, Zoom Lens are the most complex type, offering the greatest functionality once installed – unsurprisingly, Zoom lenses offer the widest choice of associated features and technologies. Zoom lenses can be remotely adjusted to allow variation of the focal length. This means that a single Lens can be used to view a wide area until an intruder is detected whereupon do it can be zoomed into capture facial details. Generally Zoom lenses incorporate an Auto Iris mechanism to permit 24-hour usage.

Focal Length

The distance from the optical center of the lens to the image of an object located at an infinite distance from the lens. Long focal lengths give a small field of view (e.g. telephoto effect), while short focal lengths give a wide angle view.

The Focal Length is measured in mm:
a short focal length (e.g. 2.5mm) = a wide angle of view
a long focal length (e.g. 16mm) = a narrow angle of view
the smaller the image sensor chip – the narrower the angle of view

Frame

A single video image; a frame is a complete video image. In the 2:1 interlaced scanning format of the RS-170 and CCIR formats, a frame is made up of two separate fields of 262.5 or 312.5 lines interlaced at 60 or 50 Hz to form a complete frame, which appears at 30 or 25 Hz. In video cameras with a progressive scan, each frame is scanned line-by-line and not interlaced; most are also displayed at 30 and 25 Hz.

Frame Rate

Frames (Images) per Second: a measurement of the rate that pictures are displayed to create a video stream. A rate of 25 FPS (PAL) or 30 FPS (NTSC) is generally considered to be full motion video. A higher frame rate is advantageous when there is movement in the video stream, as it maintains image quality throughout.

FTP

File Transfer Protocol: Used to transfer files between computers on a network, such as the Internet. Enables transfer of files from one host to other over the TCP network and is built on the client-server architecture.

Full Duplex

Simultaneous data transmission in both directions (sending and receiving); (see Duplex).

Gain

Gain is the amplification factor and the extent to which an analog amplifier boosts the strength of a signal. Amplification factors are usually expressed in terms of power. The decibel (dB) is the most common way of quantifying the gain of an amplifier.

Gateway

A gateway is a point in a network that acts as an entry point to another network. In a corporate network for example, a computer server acting as a gateway often also acts as a proxy server and a firewall server. A gateway is often associated with both a router, which knows where to direct a given packet of data that arrives at the gateway, and a switch, which furnishes the actual path in and out of the gateway for a given packet.

GIF

Graphics Interchange Format: GIF is one of the most common file formats used for images in web pages. There are two versions of the format, 87a and 89a. Version 89a supports animations, i.e. a short sequence of images within a single GIF file. A GIF89a can also be specified for interlaced presentation.

GOV

Group Of VOPs: A group of VOP’s is the basic unit of an H.264 video stream. The GOV contains different types and numbers of VOP’s (I-VOP’s, P-VOP’s, etc) as determined by the GOV length and GOV structure. See also VOP.

GOV Length

The GOV length determines the number of images (VOP’s) in the GOV structure.

GOV Structure

The GOV structure describes the composition of an H.264 video stream, as regards the type of images (I-VOP’s or P-VOP’s) included in the stream, and their internal order.

Guard Toor (PTZ)

This function records the sequence of movements of the camera’s PTZ for later playback allowing a set pattern to be repeated automatically.

H.264

Also known as MPEG-4 Part 10. This is the current widely used compression standard for digital video. H.264 offers higher video resolution than Motion JPEG or MPEG-4 at the same bit rate and bandwidth, or the same quality video at a lower bit rate.

H.265

High Efficiency Video Coding (HEVC), also known as H.265, is a video compression standard, one of several potential successors to the widely used AVC (H.264 or MPEG-4 Part 10). In comparison to AVC, HEVC offers about double the data compression ratio at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD.

Half-Duplex

Transmission of data in two directions simultaneously. In an audio system this would describe e.g. a telephone system. Half-duplex also provides bi-directional communication, but only in one direction at a time, as in a walkie-talkie system.

HDTV

High-definition television: HDTV provides up to five times higher resolution than standard analog TV. HDTV has better color fidelity and a 16:9 format. The two most important HDTV standards today are SMPTE 296M and SMPTE 274M, which are defined by the Society of Motion Picture and Television Engineers, SMPTE.

HTML

Hypertext Markup Language: HTML is the set of “markup” symbols or codes inserted in a file intended for display in web browser. The markup tells the browser how to display the page’s words and images for the user.

HTTP

Logical link between nodes & the texts for the transfer of hypertexts. Generally we refer it as the request response protocol between client & the server. Hypertext Transfer Protocol HTTP is the set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the web. The HTTP protocol runs on top of the TCP/IP suite of protocols.

HTTPS

HTTPS is a web protocol used by browsers and web servers to encrypt and decrypt user page requests and the pages returned by the server. The encrypted exchange of information is governed by the use of an HTTPS certificate (issued by a Certificate Authority), which guarantees the authenticity of the server.

Hub

A (network) hub is used to connect multiple devices to the network. The hub transmits all data to all devices connected to it, whereas a switch will only transmit the data to the device it is specifically intended for.

I-VOP

VOP (Video Object Plane):

A VOP is an image frame in an MPEG-4 video stream. There are several types of VOP:

– An I-VOP is complete image frame.

– A P-VOP codes the differences between images, as long as it is more efficient to do so. Otherwise it codes the whole image, which may also be a completely new image.

I/O’s

Inputs/Outputs (I/O’s): The digital I/Os on, for example, a network camera can be used to connect any device that can toggle between an open and a closed circuit. If, for example, a door switch is used as an input device, opening the door could trigger the upload of video images and the sending of notification messages. An output might, for example, be used to automatically start a siren when there is a motion detection trigger.

IEEE 802.11

A family of standards for wireless LANs. The 802.11 standard supports 1 or 2 Mbit/s transmission on the 2.4 GHz band. IEEE 802.11b supports data rates up to11 Mbit/s on the 2.4 GHz band, while 802.11g allows up to 54 Mbit/s on the 5 GHz band.

IEEE 802.3

IEEE 802.3 is a working group and a collection of IEEE standards produced by the working group defining the physical layer and data link layer’s media access control (MAC) of wired Ethernet. This is generally a local area network technology with some wide area network applications. Physical connections are made between nodes and/or infrastructure devices (hubs, switches, routers) by various types of copper or fiber cable. 802.3 is a technology that supports the IEEE 802.1 network architecture. 802.3 also defines LAN access method using CSMA/CD.

Image Compression

Image compression minimizes the file size (in bytes) of an image. Two of the most common compressed image formats are JPEG and GIF. See also MPEG and Motion JPEG.

Infrared

Infrared radiation is radiation at a longer wavelength than visible light, which means it cannot be seen by the naked human eye. As infrared radiation can be detected as heat, this can be shown on a screen or captured by a digital camera, with hotter objects showing up brighter against colder surroundings (e.g. a human body against a colder background).

As color cameras can “see” infrared radiation as well as visible light, these cameras are equipped with an IR-cut filter, to prevent distortion of the colors the human eye can see. To use the camera in very dark locations or at night, this filter can be removed, to allow infrared radiation to hit the image sensor and thus produce images.

An infrared lamp can be used for improved illumination for night surveillance, whilst not producing any extra visible light.

Interlaced Video

Internet Camera

The terms IP camera, network camera and Internet camera all refer to the same thing – a camera and computer combined in one unit. It operates as stand-alone unit and only requires a connection to the network.

IP

Enables interworking & is the major communication protocol for relaying the basic units associated with the packet switched networks. The Internet Protocol is a method transmitting data over a network. Data to be sent is divided into individual and completely independent “packets.” Each computer (or host) on the Internet has at least one address that uniquely identifies it from all others, and each data packet contains both the sender’s address and the receiver’s address. The Internet Protocol ensures that the data packets all arrive at the intended address. As IP is a connectionless protocol, which means that there is no established connection between the communication end-points, packets can be sent via different routes and do not need to arrive at the destination in the correct order. Once the data packets have arrived at the correct destination, another protocol – Transmission Control Protocol (TCP) – puts them in the right order.

IP Address

An IP address is simply an address on an IP network used by a computer/device connected to that network. IP addresses allow all the connected computers/devices to find each other and to pass data back and forth.

To avoid conflicts, each IP address on any given network must be unique. An IP address can be assigned as fixed, so that it does not change, or it can be assigned dynamically (and automatically) by DHCP.

An IP address consists of four groups (or quads) of decimal digits separated by periods, e.g. 130.5.5.25. Different parts of the address represent different things. Some part will represent the network number or address, and some other part will represent the local machine address. See also IP (Internet Protocol).

IP Camera

IR

An infrared lamp can be used for improved illumination for night surveillance, whilst not producing any extra visible light.

IRE

Institute of Radio Engineers: A measurement of video amplitude that divides the area from the bottom of sync to peak white level into 140 equal units – 140 IRE equals 1V peak-to-peak. The range of active video is 100 IRE. The institute itself was founded 1912 in New York City, merged to form IEEE in 1957.

iSCSI

Internet Small Computer System Interface: Protocol that manages storage via a TCP/IP network. iSCSI enables access to stored data from everywhere in the network.

ISDN

Integrated Services Digital Network: Comprised of digital telephony and data-transport services offered by regional telephone carriers. ISDN involves the digitization of the telephone network, which permits voice, data, text, graphics, music, video, and other source material to be transmitted over existing telephone wires.

ISMA

Internet Streaming Media Alliance: ISMA has created a specification to facilitate interoperability between different clients and servers when transmitting MPEG-4 on a network.

JPEG

Joint Photographic Experts Group: The name of the committee that created a standard for encoding still images. JPEG is a “lossy compression” technique for color images. Although it can reduce files sizes to about 5% of their normal size, some detail is lost in the compression.

kBit/s

Kilobits per second: The actual data rate.

LAN

Local Area Network: A communications network serving users within a limited geographical area, such as a building or a university campus. It is controlled by a network operating system and uses a transfer protocol.

Light Sensitivity

The amount of light needed for the camera to produce an image of useable quality. Minimum illumination is presented in lux (lx), which is a measure of luminance. In general, provided it is not overexposed, the image will be better the more light that is available in the scene. If the amount of light is insufficient, the image will be noisy or dark. The amount of light that is required to produce a good-quality image depends on the camera and how sensitive to light it is.

Linux

Linux is an open source operating system within the Unix family. Because of its robustness and availability, Linux has won popularity in the open source community and among commercial application developers.

LUN

Logical Unit Number: Logical drive in iSCSI storage systems

Lux

The International System Unit (see SI) of measurement of the intensity of light. It is equal to the illumination of a surface one meter away from a single candle.

MAC

Media Access Control: A quasi-unique identifier attached to most network adapters (NICs). It is a number that acts like a name for a particular network adapter.

Main Stream

Manual Iris

This is the opposite of an autoiris, i.e. the camera iris must be adjusted manually to regulate the amount of light allowed to reach the image sensor.

Mbit/s

Megabits per second: A measure of the bit rate, i.e. the rate at which bits are passing a given point. Commonly used to give the “speed” of a network. A LAN might run at 10 or 100 Mbit/s.

Megapixel

A megapixel is one million pixels. It is commonly used to describe the resolution of cameras. Megapixel security cameras are offer in IP, HD-TVI, HD-CVI, HD-SDI and AHD CCTV formats.

MIB

Management Information Base: A collection of information for remote servicing using the SNMP protocol.

Minimum Illumination

The smallest amount of light needed for the camera to produce an image of useable quality. Minimum illumination is presented in lux (lx), which is a measure of luminance. In general, provided it is not overexposed, the image will be better the more light that is available in the scene. If the amount of light is insufficient, the image will be noisy or dark. The amount of light that is required to produce a good-quality image depends on the camera and how sensitive to light it is.

MJPEG

Motion JPEG is a digital video encoding standard where each video frame is separately compressed into a JPEG image.

Modal Dispersion

A broadening of a waveform over long distances. Modal Dispersion (or Intermodal Dispersion) occurs in multimode fibers, because light is bounced down different reflective paths (e.g. modes) in the fiber. As the distance increases, the path (mode) begins to spread and the arrival time for the different light rays begins to vary. A large variance (dispersion) increases the chance that the optical receiver may interpret the incoming signals incorrectly. Modal dispersion is a major problem with multimode fibers.

Monitor

A monitor is very similar to a standard television set, but lacks the electronics to pick up regular television signals.

Motion Detection

Video Motion Detection: An algorithm for motion detection in which the camera compares the current image with a reference image and counts the number of pixels (see Pixel) that have changed between the two images. An alarm is generated when the number of pixel changes exceeds a user-configured threshold.

Motion JPEG

Motion JPEG is a simple compression/decompression technique for network video. Latency is low and image quality is guaranteed, regardless of movement or complexity of the image. Image quality is controlled by adjusting the compression level, which in turn provides control over the file size, and thereby the bit rate. High-quality individual images from the Motion JPEG stream are easily extracted.

MPEG

Moving Picture Experts Group: The Moving Picture Experts Group develops standards for digital video and audio compression. It operates under the auspices of the International Organization for Standardization (ISO). The MPEG standards are an evolving series, each designed for a different purpose.

MPEG-2

MPEG-2 is the designation for a group of audio and video coding standards, and is typically used to encode audio and video for broadcast signals, including digital satellite and Cable TV. MPEG-2, with some modifications, is also the coding format used by standard commercial DVD movies.

MPEG-4

A further development of MPEG-2 designed for transmitting audiovisual data at very low transfer rates (for example over the Internet). A digital video encoding and compression standard that uses interframe encoding to significantly reduce the size of the video stream being transmitted. With interframe coding, a video sequence is made up of keyframes that contain the entire image. In between the keyframes are delta frames, which are encoded with only the incremental differences. This often provides substantial compression because in many motion sequences, only a small percentage of the pixels are actually different from one frame to another.

Multi-Protocol

A convention or standard that controls or enables the connection, communication, and data transfer between two devices. In PTZ cameras, such as the AutoDome and Pan/Tilt units, protocol refers to the standard used to control the pan, tilt, and zoom (PTZ) operation of the camera. Since each camera manufacturer’s PTZ protocols are unique, multi-protocol support is needed to support third party systems.

Multicast

Bandwidth-conserving technology that reduces bandwidth usage by simultaneously delivering a single stream of information to multiple network recipients.

Multimode Fiber

An optical fiber with a larger core (typically 50 or 62.5 microns) than singlemode fiber (see Singlemode Fiber). The core is made of plastic or glass fibers. It is the most commonly used fiber for cabling short distances as used in LANs. The name multimode comes from the fact that light rays travel down multiple reflective paths (modes) within the fiber. This allows light to enter the core at different angles, making it easier to connect to broader light sources such as LEDs (light emitting diodes). Fiber optic interfaces and multimode fiber-based transmission systems are less expensive than those based on singlemode fiber. However, the use of multiple reflective paths (modes) increases modal dispersion (see Modal Dispersion) and shortens the distances that this type of fiber optic transmission system can span.

Multiplexer

A multiplexer is a high-speed switch that provides full-screen images from up to 16 analog cameras. Multiplexers can playback everything that happened on any one camera with no interference from the other cameras on the system.

NEMA Rating

Electrical Standards and Publications published by NEMA (National Electrical Manufacturers Association). Specification standards in reference to the operating environment for a variety of electrical devices.

NEMA Ratings and IP Equivalency Chart

NEMA Rating	IP Equivalent	NEMA Definition	IP Definition
1	IP10	Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment and to provide a degree of protection against falling dirt	1 = Protected against solid foreign objects of 50mm in diameter and greater	0 = Not Protected
2	IP11	Enclosures constructed for indoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment, to provide a degree of protection against falling dirt, and to provide a degree of protection against dripping and light splashing of liquids	1 = Protected against solid foreign objects of 50mm in diameter and greater	1 = Protected against vertically falling water drops
3	IP54	Enclosures constructed for either indoor or outdoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to proved a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and that will undamaged by external formation of ice on the enclosure	5 = Protected against dust – Limited to ingress (no harmful deposit)	4 = Protected against water sprayed from all directions – Limited to ingress permitted.
3R	IP14	Enclosures constructed for either indoor or outdoor used to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, and snow; and that will be undamaged by external formation of ice on the enclosure	1 = Protected against vertically falling water drops	4 = Protected against water sprayed from all directions – Limited to ingress permitted.
3S	IP54	Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, and windblown dust; and in which the external mechanism(s) remain operable when ice laden.	5 = Protected against dust – Limited to ingress (no harmful deposit)	4 = Protected against water sprayed from all directions – Limited to ingress permitted.
4	IP66	Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water; and that will be undamaged by the external formation of ice on the enclosure	6 = Totally protected against dust	6 = Protected against strong jets of water from all directions – Limited to ingress permitted.
4X	IP66	Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, hose-directed water, and corrosion; and that will be undamaged by thee external formation of ice on the enclosure	6 = Totally protected against dust	6 = Protected against strong jets of water from all directions – Limited to ingress permitted.
5	IP52	Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against settling airborne dust, lint, fibers, and flyings; and to provide a degree of protection against dripping and light splashing of liquids.	5 = Protected against dust – Limited to ingress (no harmful deposit)	2 = Protected against direct sprays of water up to 15° from the vertical.
6	IP67	Enclosures constructed for either indoor or outdoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against hose-directed water and the entry of water during occasional temporary submersion at a limited depth; and that will be undamaged by the external formation of ice on the enclosure.	6 = Totally protected against dust	7 = Protected against the effects of temporary immersion between 15cm and 1m. Duration of test 30 minutes.
6P	IP67	Enclosures constructed for either indoor or outdoor use to provide a degree of protection to the personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against hose-directed water and the entry of water during prolonged submersion at a limited depth; and that will be undamaged by the external formation of ice on the enclosure	6 = Totally protected against dust	7 = Protected against the effects of temporary immersion between 15cm and 1m. Duration of test 30 minutes.
12 and 12K	IP52	Enclosures constructed (without knockouts) for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibers, and flying; and against dripping and light splashing of liquids	5 = Protected against dust – Limited to ingress (no harmful deposit)	2 = Protected against direct sprays of water up to 15° from the vertical.
13	IP54	Enclosures constructed for indoor use to provide a degree of protection to personnel against incidental contact with the enclosed equipment; to provide a degree of protection against falling dirt; against circulating dust, lint, fibers, and flyings; and against the spraying, splashing, and seepage of water, oil, and noncorrosive coolants.	5 = Protected against dust – Limited to ingress (no harmful deposit)	4 = Protected against water sprayed from all directions – Limited to ingress permitted.

Net mask

A mask that explains which part of an IP address is the network address and which part is the host address. It is usually written in dotted decimal notation, for example 255.255.255.192 (see also Subnet Mask).

Network Camera

NPT

National Pipe Thread: A U.S. standard for tapered threads. NPT sizes measure the nominal inside diameter of the pipe. NPT threads form a seal as the threads compress against each other.

NTP

Network Time Protocol: A standard for synchronizing computer system clocks via packetbased communication networks. NTP uses the connectionless network protocol UDP (see UDP). This was developed specifically for enabling time to be reliably transmitted over networks with variable packet runtime (Ping).

NTSC

National Television System Committee: NTSC is an analog color encoding system used in television systems in Japan, the United States and other parts of the Americas. NTSC defines the video signal using 525 TV lines per frame, at a refresh rate equal to 30 frames per second.

OEM

Original Equipment Manufacturer: This is a designation for companies that manufacture equipment that is then marketed and sold to other companies under their own names.

ONVIF

ONVIF (Open Network Video Interface Forum) is a global and open industry forum with the goal to facilitate the development and use of a global open standard for the interface of physical IP-based security products. Or in other words, to create a standard for how IP products within video surveillance and other physical security areas can communicate with each other. ONVIF is an organization started in 2008 by Axis Communications, Bosch Security Systems and Sony.

ONVIF states that the benefits of an open standard include:

Interoperability – products from various manufacturers can be used in the same systems and “speak the same language”.
Flexibility – end-users and integrators are not locked within proprietary solutions based on technology choices of individual manufacturers.
Future-proof – standards ensure that there are interoperable products on the market, no matter what happens to individual companies.
Quality – when a product conforms to a standard, the market knows what to expect from that product.

ONVIF Profile S Versions

Feature	Realtime Viewing	Record Video	PTZ Control	Audio Recording	Digital Input	Motion Detection	Access Control Integration	Network Video Storage	Video Analytics	NVR POE Plugs
ONVIF		X
ONVIF 2.0	X	X	X	X	X
ONVIF 2.1	X	X	X	X	X
ONVIF 2.2	X	X	X	X	X	X
ONVIF 2.3	X	X	X	X	X	X	X
ONVIF 2.4	X	X	X	X	X	X	X	X	X
ONVIF 2.42	X	X	X	X	X	X	X	X	X	X

*ONVIF Specification History

ONVIF Profiles

Building on ONVIF Specifications, ONVIF Profiles are collections specifications that guarantee the interoperability of specific features between conformant devices.

Profile S – Addresses common functionalities of IP video systems, such as video and audio streaming, PTZ controls, and relay activation.
Profile C – Addresses common functionalities of IP access control systems, such as door state and control, credential management, and event handling.
Profile G – Addresses video storage, recording, search, and retrieval.
Profile Q (Release Candidate) – Addresses device discovery and configuration, as well as the management of TLS certificates and keys.
Profile A (Release Candidate) – Establishes an interface for access control clients and expands the configuration options for ONVIF conformant access control systems.

ONVIF Specification

The ONVIF Core Specification aims to standardize the network interface (on the network layer) of network video products. It defines a network video communication framework based on relevant IETF and Web Services standards including security and IP configuration requirements. The following areas are covered by the Core Specification version 1.0:

IP configuration
Device discovery
Device management
Media configuration
Real time viewing
Event handling
PTZ camera control
Video analytics
Security

ONVIF utilizes IT industry technologies including SOAP, RTP, and Motion JPEG, MPEG-4, and H.264 video codecs. Later releases of the ONVIF specification (version 2.0) also covers storage and additional aspects of analytics.

OSD

On-screen Display: Menus are shown on the display monitor.

P-Iris

P-Iris is an automatic, precise iris control developed by Axis Communications of Sweden and Kowa Company of Japan. It involves a P-Iris lens and specialized software that optimize image quality.

P-VOP

VOP (Video Object Plane):

A VOP is an image frame in an MPEG-4 video stream. There are several types of VOP:

– An I-VOP is complete image frame.

– A P-VOP codes the differences between images, as long as it is more efficient to do so. Otherwise it codes the whole image, which may also be a completely new image.

PAL

Phase Alternating Line: PAL is an analog color encoding system used in television systems in Europe and in many other parts of the world. PAL defines the video signal using 625 TV lines per frame, at a refresh rate equal to 25 frames per second. See also NTSC.

Pan

Camera movement in the horizontal direction.

Parameters

Values used for configuration.

PEM

Privacy Enhanced Mail: An early standard for securing electronic mail. The PEM-format is often used for representing an HTTPS certificate or certificate request.

Ping

Ping is a basic network program used diagnostically to check the status of a network host or device. Ping can be used to see if a particular network address (IP address or host name) is occupied or not, or if the host at that address is responding normally. Ping can be run from e.g. the Windows Command prompt or the command line in Unix.

Pixel

The smallest addressable unit on a display screen or bitmapped image. A pixel is one of the many tiny dots that make up a digital image. The color and intensity of each pixel represents a tiny area of the complete image.

PoE – Power Over Ethernet

Power over Ethernet provides power to a network device via the same cable as used for the network connection. This is very useful for IP-Surveillance and remote monitoring applications in places where it may be too impractical or expensive to power the device from a power outlet.

Port

1) On computer and telecommunication devices, a port (noun) is generally a specific place for being physically connected to some other device, usually with a socket and plug of some kind. Typically, a personal computer is provided with one or more serial ports and usually one parallel port. 2) In programming, a port (noun) is a logical connection place and specifically, using the Internet protocol TCP/IP, the way a client program specifies a particular server program on a computer in a network. Higher-level applications that use TCP/IP, such as the Web protocol Hypertext Transfer Protocol, have ports with preassigned numbers. These are known as well-known ports that have been assigned by the Internet Assigned Numbers Authority (IANA). Other application processes are given port numbers dynamically for each connection. When a service (server program) initially is started, it is said to bind to its designated port number. As any client program wants to use that server, it also must request to bind to the designated port number. Port numbers are from 0 to 65535. Ports 0 to 1024 are reserved for use by certain privileged services. For the HTTP service, port 80 is defined as a default and it does not have to be specified in the Uniform Resource Locator (URL).

PPP

Point-to-Point Protocol: A protocol that uses a serial interface for communication between two network devices. For example, a PC connected by a phone line to a server.

PPTP

Point-to-Point Tunneling Protocol: A protocol that allows corporations to extend their own corporate network through private “tunnels” over the public Internet. In this way a corporation can effectively use a WAN (Wide Area Network) as a large single LAN (Local Area Network). This kind of interconnection is known as a virtual private network (VPN).

Pre / Post Alarm Images

The images from immediately before and after an alarm. These images are stored in a buffer for later retrieval.

Pre-Position

A pre-selected and stored combination of pan, tilt, and zoom positions that allow a set view to be recalled. Also known as Preset Shot.

Preset Tour

A sequence of preset shots combined to provide a pre-programmed tour of the area covered by a programmable camera.

Pressurized Dry Nitrogen Housing

A housing for outdoor applications that protects against smog, humidity, dirt, and dust.

Privacy Masking

The ability to mask or block out a specific area to prevent it from being viewed.

Progressive Scan

Progressive scan, as opposed to interlaced video, scans the entire picture, line by line every sixteenth of a second. In other words, captured images are not split into separate fields as in interlaced scanning.

Computer monitors do not need interlace to show the picture on the screen, but instead show them progressively, on one line at a time in perfect order i.e. 1, 2, 3, 4, 5, 6, 7 etc., so there is virtually no “flickering” effect. In a surveillance application, this can be critical when viewing detail within a moving image, such as a person running. A high-quality monitor is required to get the best from progressive scan.

Protocol

A special set of rules governing how two entities will communicate. Protocols are found at many levels of communication, and there are hardware protocols and software protocols.

Proxy Server

In an enterprise that uses the Internet, a proxy server acts as an intermediary between a workstation user and the Internet. This provides security, administrative control, and a caching service. Any proxy server associated with a gateway server, or part of a gateway server, effectively separates the enterprise network from the outside network and the local firewall. It is the firewall server that protects the enterprise network from outside intrusion. A proxy server receives requests for Internet services (such as web page requests) from many users. If the proxy server is also a cache server, it looks in its local cache of previously downloaded web pages. If it finds the page, it is returned to the user without forwarding the request to the Internet. If the page is not in the cache, the proxy server, acting as a client on behalf of the user, uses one of its own IP addresses to request the page from another server over the Internet. When the requested page is returned, the proxy server forwards it to the user that originally requested it.

QCIF

Quarter CIF: Video format with 176 × 144/120 pixels (see CIF).

QoS

Quality of Service: QoS provides the means to guarantee a certain level of a specified resource to selected traffic on a network. Quality can be defined as a maintained level of bandwidth, low latency, no packet losses, etc. The QoS in network video products marks the data packets for various types of network traffic originating from the product. This makes it possible for network routers and switches to reserve a fixed amount of bandwidth for these types of traffic.

Quad View

A Quad view displays images from up to four cameras on a single screen; where the images from each camera take up approximately a quarter of the display area.

RADIUS Server

Remote Authentication Dial-In User Service: A client/server protocol for the authentication, authorization, and accounting of users with dial-up connections on a computer network. RADIUS is the de-facto standard for central authentication of dial-up connections via a Modem, an ISDN, a VPN, a Wireless LAN (see IEEE 802.1x), and a DSL connection.

RAID

Redundant Array of Independent Disks: Used for organizing two or more hard disks as if they were one drive. On such a drive data is shared or replicated. This is used to achieve greater capacity, reliability, and speed.

Region of Interest

A specific area within a field of view, used by the motion detection algorithm to identify motion. A region of interest is a specified part of a CCTV camera view that is highlighted and broadcast to a separate stream from a camera. Usually a feature on higher mega pixel IP CCTV camera’s, this technology uses the definition and resolution of mega pixel IP camera’s to allow a digitally zoomed in section of a camera’s view to be broadcast on a separate stream whilst still retaining the original overview from the camera. This feature is great for highlighting area’s such as doors or areas of access where an overall scene view is still required.

Resolution

The measure of the fine detail that can be seen in an image. For analog systems this is typically measured in Television Lines or TVL. The higher the TVL rating, the higher the resolution.

Megapixel cameras can capture video at much higher resolutions. A megapixel camera that is 1.3 megapixels has a resolution of 1280 x 1024. From there the megapixels go up. 2, 3, 5, and on up to 16mp. However they are not able to capture images at 30 fps. They typically are only capturing 3 to 7 fps. Megapixel cameras can display higher than HDTV resolutions on PC monitors that support higher resolutions.

RFC 868

A Request For Comment protocol for synchronizing computer clocks over the Internet.

Router

A device that determines the next network point to which a packet should be forwarded on its way to its final destination. A router creates and/or maintains a special routing table that stores information on how best to reach certain destinations. A router is sometimes included as part of a network switch.

RS-232 / RS-422 / RS-485

Recommended standards for serial data transmission. A communication interface for third party control, firmware upgrades, and service purposes for camera and DVR products.

RS-232: RS-232 is a long-established standard that describes the physical interface and protocol for low-speed serial data communication between devices. This is the interface that e.g. a computer uses to talk to and exchange data with a modem and other serial devices.

RS-422: RS-422 is a serial data communication protocol that specifies 4-wire, full-duplex, differential line, multi-drop communications. It provides balanced data transmission with unidirectional/non-reversible, terminated or non-terminated transmission lines. RS-422 does not allow multiple drivers, only multiple receivers. Maximum recommended range is 4,000 feet (1200 meters). Maximum recommended baud rate is 10Mbit/s.

RS-485: RS-485 is an upgraded version of RS-422 that supports up to 32 devices on the same connection. RS-485 is an electrical specification of a two-wire, half-duplex, multipoint serial connection. It enables the configuration of inexpensive local networks and multidrop communications links. It offers high data transmission speeds (up to 10Mbit/s), and as it uses a differential balanced line over twisted pair (like RS-422), it can span relatively large distances (4000 feet or 1200 meters). RS-485 only specifies the electrical characteristics of the driver and the receiver. It does not specify or recommend any data protocol.

RTCP

Real-Time Control Protocol: RTCP provides support for real-time conferencing of groups of any size within an intranet. This support includes source identification and support for gateways like audio and video bridges as well as multicast-to-unicast translators.

RTP

Realtime Transport Protocol: A transfer protocol for real-time video and audio.

RTSP

Enables to control the streaming media servers by establishing & controlling the media sessions between the end points.

Rule

An alarm management subsystem that uses rules to perform specific actions when an event occurs.

Sector Blanking

The ability to blank out video in any number of the pan sectors.

Sensitivity

A measure of the amount of light required to provide a standard video signal. Sensitivity values are stated in lux (see Lux) or foot-candles.

SensUp

Ups (increases) camera sensitivity by increasing the integration time on the CCD. This is accomplished by integrating the signal from a number of consecutive video frames to reduce signal noise.

Server

In general, a server is a computer program that provides services to other computer programs in the same or other computers. A computer running a server program is also frequently referred to as a server. In practice, the server may contain any number of server and client programs. A web server is the computer program that supplies the requested HTML pages or files to the client (browser).

SFP

Small Form-factor Pluggable: A small, standardized module for network connections; designed as a plug connector for high-speed network connections.

Sharpness

This is the control of fine detail within a picture. This feature was originally introduced into color TV sets that used notch filter decoders. This filter took away all high frequency detail in the black and white region of the picture. The sharpness control attempted to put some of that detail back in the picture. Sharpness controls are mostly superfluous in today’s high-end TVs. The only logical requirement for it nowadays is on a VHS machine.

SI

International System of Units (abbreviated SI from the French Le Système international d’unités): The world’s most widely used system of units, both in everyday commerce and in science.

Simplex

In simplex operation, a network cable or communications channel can only send information in one direction.

Singlemode Fiber

An optical fiber with a silica (or glass) core with a diameter of less than 10 microns. Used for high-speed transmission over long distances, it provides greater bandwidth than multimode (see Multimode Fiber), but its smaller core makes it more difficult to couple the light source. Singlemode fiber optic transmission systems use more expensive laser-based light sources.

SMTP

Simple Mail Transfer Protocol: SMTP is used for sending and receiving e-mail. However, as it is “simple,” it is limited in its ability to queue messages at the receiving end, and is usually used with one of two other protocols, POP3 or IMAP. These other protocols allow the user to save messages in a server mailbox and download them periodically from the server.

SMTP authentication is an extension of SMTP, whereby the client is required to log into the mail server before or during the sending of email. It can be used to allow legitimate users to send email while denying the service to unauthorized users, such as spammers.

SNIA

Storage Networking Industry Association: Association of companies for defining the iSCSI standard.

SNMP

Simple Network Management Protocol: IP based protocol for network management, as well as managing and monitoring network components. SNMP allows getting information from networking devices (GET), to set parameters on network devices (SET), and to be notified about certain events (EVENT).

SNTP

Simple Network Time Protocol: A simplified version of NTP (see NTP).

Sockets

Sockets are a method for communication between a client program and a server program over a network. A socket is defined as “the endpoint in a connection.” Sockets are created and used with a set of programming requests or “function calls” sometimes called the sockets application programming interface (API).

Speed Dome

Fully integrated, high speed, pan/tilt/zoom camera built into a protective dome housing allowing full and continuous 360° coverage of the scene.

Spot Focus

Activates Auto Focus for number of seconds after camera movement.

SSL/TLS

Secure Socket Layer/Transport Layer Security: These two protocols (SSL is succeeded by TLS) are cryptographic protocols that provide secure communication on a network. SSL is commonly used over HTTP to form HTTPS, as used e.g. on the Internet for electronic financial transactions. SSL uses public key certificates to verify the identity of the server.

Sub-Stream

Subnet

A subnet is an identifiably separate part of an organization’s network. Typically, a subnet may represent all the machines at one geographic location, in one building, or on the same local area network (LAN). Having an organization’s network divided into subnets allows it to be connected to the Internet with a single shared network address.

The subnet mask is the part of the IP address that tells a network router how to find the subnet that the data packet should be delivered to. Using a subnet mask saves the router having to handle the entire 32-bit IP address; it simply looks at the bits selected by the mask.

Subnet Mask

Subnetting is a method that allows one large network to be broken down into several smaller ones. IP addresses are grouped by something called a subnet mask. Every IP address has a corresponding subnet mask. The subnet mask specifies the range of the IP addresses in a group. The subnet mask looks a lot like an IP address. It is made up of four eight-bit numbers separated by periods. These numbers once again range from 0 to 255. A typical subnet mask is 255.255.255.0.

Switch

A switch is a network device that connects network segments together, and which selects a path for sending a unit of data to its next destination. In general, a switch is a simpler and faster mechanism than a router, which requires knowledge about the network and how to determine the route. Some switches include the router function.

TCP

Transmission Control Protocol: TCP is used along with the Internet Protocol (IP) to transmit data as packets between computers over the network. While IP takes care of the actual packet delivery, TCP keeps track of the individual packets that the communication (e.g. requested a web page file) is divided into, and, when all packets have arrived at their destination, it reassembles them to re-form the complete file.

TCP is a connection-oriented protocol, which means that a connection is established between the two end-points and is maintained until the data has been successfully exchanged between the communicating applications.

TCP/IP

Transmission Control Protocol/Internet Protocol: a communications protocol suite that provides two data transport methods. TCP is a connection-based protocol that ensures that data arrives intact and complete. UDP is a connectionless, best effort protocol that simply sends out packets. UDP is typically used for streaming media, while TCP is used when errorfree delivery is required.

Telnet

Log in protocol with which users can access a remote computer (Host) on the Internet or local area network (LAN) connections.

TFTP

Enables the client to put or get the files from the remote host, and is widely used at the initial stages for devices booting from the LAN’s.

Tilt

Camera movement in the vertical direction.

TLS

Transport Layer Security (TLS) is a protocol that ensures privacy between communicating applications and their users on the Internet. When a server and client communicate, TLS ensures that no third party may eavesdrop or tamper with any message. Transport Layer Security: TLS 1.0, 1.1, and the standard advanced developments of SSL 3.0 (Secure Sockets Layer, the predecessor to TLS).

Tri-Streaming

An encoding technology that generates three separate video streams simultaneously. This advanced streaming capability enables the user to tune live viewing and recording requirements independently to meet specific site and enterprise requirements. Generally main stream is highest quality intended to be viewed live and/or recorded; sub-streams are usually used for remote phone and computer viewing due to the large bandwidth required for HD video.

TTL

Time-To-Live: Life cycle of a data packet in station transfers

TVL

TV Lines: A method of defining resolutions in analog video.

UDP

User Datagram Protocol: One of the core protocols of the Internet Protocol suite. Using UDP, programs on networked computers can send short messages, sometimes known as datagrams, (using Datagram Sockets) to one another. UDP is sometimes called the Universal Datagram Protocol.

UDP is an alternative to the Transmission Control Protocol (TCP). The advantage of UDP is that it is not required to deliver all data and may drop network packets when there is e.g. network congestion. This is suitable for live video, as there is no point in re-transmitting old information that will not be displayed anyway.

Unicast

Communication between a single sender and a single receiver over a network. A new connection is established for each new user.

UPnP

Enables networked devices to discover each other’s presence on the network so that data sharing is possible. A set of computer network protocols that allows the automatic peer-to-peer detection of devices on the network. UPnP is promoted by the UPnP Forum.

URL

URL is an acronym for Uniform Resource Locator and is a reference (an address) to a resource on the Internet. A URL has two main components: Protocol identifier: For the URL http://example.com , the protocol identifier is http . Resource name: For the URL http://example.com , the resource name is example.com .

USB

Universal Serial Bus: A plug-and-play interface between a computer and peripheral devices (scanners, printers etc).

UTP

Unshielded Twisted Pair: A variant of twisted pair cabling, UTP cable is not surrounded by any shielding. The wires in a twisted pair cable are twisted around each other to minimize interference from the other twisted pairs in the cable. UTP is the primary wire type for telephone usage and the most commonly used type of networking cable.

Varifocal Lens

A varifocal lens is a camera lens with variable focal length in which focus changes as focal length (and magnification) changes. A fixed lens doesn’t let you adjust the focal length, angle of view, and level of zoom. With a varifocal camera, you can adjust these things.

Video Encoder

Virtual Masking

A technology that creates invisible motion masking areas. These invisible masks are similar to privacy zones but only the camera’s algorithms can see them. This allows the camera to ignore areas of unwanted motion.

VOP

VOP (Video Object Plane):

A VOP is an image frame in an MPEG-4 video stream. There are several types of VOP:

– An I-VOP is complete image frame.

– A P-VOP codes the differences between images, as long as it is more efficient to do so. Otherwise it codes the whole image, which may also be a completely new image.

VPN

Virtual Private Network: This creates a secure “tunnel” between the points within the VPN. Only devices with the correct “key” will be able to work within the VPN. The VPN network can be within a company LAN (Local Area Network), but different sites can also be connected over the Internet in a secure way. One common use for VPN is for connecting a remote computer to the corporate network, via e.g. a direct phone line or via the Internet.

W-LAN

Wireless LAN: A wireless LAN is a wireless local area network that uses radio waves as its carrier: where the network connections for end-users are wireless. The main network structure usually uses cables.

WAN

Wide Area Network: A long distance link used to extend or connect remotely-located local area networks.

Web Server

A Web server is a program, which allows Web browsers to retrieve files from computers connected to the Internet. The Web server listens for requests from Web browsers and upon receiving a request for a file sends it back to the browser. The primary function of a Web server is to serve pages to other remote computers; consequently, it needs to be installed on a computer that is permanently connected to the Internet. It also controls access to the server whilst monitoring and logging server access statistics.

WEP

Wired Equivalent Privacy: A wireless security protocol, specified in the IEEE 802.11 standard, which is designed to provide a wireless local area network (WLAN) with a level of security and privacy comparable to that usually expected of a wired LAN. Security is at two different levels; 40-bit and 128-bit encryption. The higher the bit number, the more secure the encryption.

WINS

Windows Internet Naming Service: Part of the Microsoft Windows NT Server, WINS manages the association of workstation names and locations with IP addresses, without the user or administrator having to be involved in each configuration change.

WPA-PSK

Wi-Fi Protected Access – Pre-Shared Key: This wireless encryption method uses a pre-shared key (PSK) for key management. Keys can usually be entered as manual hex values, as hexadecimal characters, or as a Passphrase. WPA-PSK provides a greater degree of security than WEP.

Zoom

Changing the effective focal length to allow different fields of view to fill the picture area. Zoom can be optical, where the lens is adjusted, or digital, where a portion of the view selected is magnified electronically. Image quality degrades using digital zoom.

Zoom Lens

A zoom lens can be moved (zoomed) to enlarge the view of an object to show more detail.