IEEE 802.11b standard - wireless network standard, which allows the flow rate up to 11 Mb/s and the maximum range, can be up to approx. 50 m indoors and approx. 100 m outdoors. The range can be increased by means of directional antennas. In Poland, the bandwidth available for this type of network is within the range of 2.4 GHz ...2.4835 GHz which corresponds to 13 channels.
IEEE 802.11g standard - standard of wireless network, which was designed as an extension to 802.11b. It increases data flow capacity to 54 Mbit/s using the same 2.4 GHz bandwidth, which is used in 802.11b. With a high density of users there are problems with interference and adequate data flow capacity of channels, so this standard is replaced, even by IEEE 802.11n.
IEEE 802.11n standard - a standard for a wireless network using multiple antennas in order to increase data transmission rate. It can be used in two frequency bandwidths: 2.4 GHz and 5 GHz with a theoretical speed of up to 600 Mb/s. Currently, in practice it is reaching the speed of approx. 440 Mbit/s.
A device must be equipped with an aerial to send and receive radio waves. Many contemporary devices have embedded aerials (e.g. mobile phones). There are many aerial types available on the market. There are also various aerial classifications.
AHD (Analog High Definition) - a standard that allows signal transmission in HD (1280x720), Full HD (1920x1080), 3 Mpx (2048x1536) and 4 Mpx (2560x1440) quality through 75 Ω coaxial cable or twisted-pair cable with video transformers.
AC (Alternating Current) - an alternating current, which is characterized by changes in the instantaneous values in a particular frequency while maintaining repeatability. AC takes alternately positive and negative values in sine curve characteristics.
This is the width of visual field expressed in degrees. This is dependant among others on the type of lens used in the camera, and the focal length of these lens. For lenses used in industrial cameras this is a horizontal angle.
CRI (Colour Rendering Index) – a given light source index which specifies the degree of colour rendering in objects lit with this light. This parameter falls within the range from 0 to 100 Ra; the higher the index, the better the colours of objects are rendered in a given light.
Composite Video, also known as CVBS (Composite Video Baseband Signal) is an analogue video transmission signal (with no sound) which carries information in the standard resolution of 480 i or 576 i (480 lines or 576 lines with interlacing).
dBi - power gain ("G"), expressed in dBi unit informs us by what value in decibels the antenna gain is larger in relation to hypothetical isotropic antenna, assuming that both antennas are supplier with identical power.
DC (Direct Current) - direct current, whose value does not change over time. Contrary to alternating current (AC), charges move always in one direction, by which it is characterized by a constant and changeless direction of their flow.
E.I.R.P. (Effective Isotropic Radiated Power) - effective isotropic radiated power means by the definition of "power that would have to be radiated by a hypothetical isotropic antenna to obtain the same level of signal in direction of maximum radiation of given antenna".
Focal length is a distance between an optical focus of an optical system and a cardinal point of the optical system in millimeters and is defined as the lens system ability to focus light. The smaller the focal length, the more the light beams are focused by the optical system.
HD-CVI (High Definition Composite Video Interface) - a standard that allows signal transmission in HD (1280x720), Full HD (1920x1080) and 4 Mpx (2560x1440) quality through 75 Ω coaxial cable or twisted-pair cable with video transformers.
HD-TVI (High Definition Transport Video Interface) - a standard that allows signal transmission in HD (1280x720), Full HD (1920x1080), 3 Mpx (2048x1536), 4 Mpx (2688x1520) and 5 Mpx (2560x1944) quality through 75 Ω coaxial cable or twisted-pair cable with video transformers.