AutoDome Modular Camera System
Glossary of CCTV Terms | en
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Bosch Security Systems, Inc.
VG4-200, VG4-300, VG4-500i Series User’s Manual
F01U073308 | 3.0 | 2007.09
Singlemode Fiber
An optical fiber with a silica (e.g. glass) core with a diameter of less than 10 microns. Used for
high-speed transmission over long distances, it provides greater bandwidth than multimode,
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.
Spot Focus
Activates Auto Focus for three seconds after camera movement.
Subnet Mask
Subnetting is a method that allows one large network to be broken down into several smaller
ones. Depending on the network class (A, B, or C), some number of IP address bits are
reserved for the network address (subnet) and some for the host address. For example, Class
A addresses use 8 bits for the subnet address and 24 bits for the host portion of the address.
Class A subnet masks are denoted 255.0.0.0. Class B addresses (16 bits for both the subnet
and host address) use a 255.255.0.0 subnet mask. Class C addresses (8 bits for the subnet
and 24 bits for the host address) use a subnet mask of 255.255.255.0.
T
TCP/IP
See Transmission Control Protocol/Internet Protocol.
Tilt
Camera movement in the vertical direction.
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 error-free delivery is required.
Tri-streaming
A Bosch encoding technology that generates two separate MPEG-4 video streams and one
MJPEG stream simultaneously. This advanced streaming capability enables the user to tune
live viewing and recording requirements independently to meet specific site and enterprise
requirements.
U
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.
UTP
See Unshielded Twisted Pair.
V
Virtual Masking
A unique Bosch technology that allows for the creation of “invisible” motion masking areas.
These invisible masks are similar to privacy zones, but only the AutoDome’s AutoTrack II and
Video Motion Detection algorithms can see them. This allows the AutoDome to ignore areas of
unwanted motion.
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.
