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Refer to
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WDR
networks (WAN/LAN) and effectively utilize scarce IP address resources. This is also
referred to as IP masquerade or NAPT.
Port number
This is the upper layer process of an IP that accepts information from the lower layer. TCP
and UDP network protocols are identifiers used to differentiate between programs.
Protocol
This term refers to the rules of transmission. Protocol provides a definition of the procedures
that should be followed when sending and receiving data.
Quarter common intermediate format (QCIF)
With QCIF, the resolution of CIF is reduced in similar proportion by half and the resolution
becomes 176 x 144 pixels. The number of pixels is one-fourth that of CIF and this format
supports moving images at a data rate of up to 30 frames per second.
Quality level
This is used for JVC IP Products' JPEG images to determine to what extent the original image
should be compressed. There are settings for either seven levels or three levels (high,
medium and low). Quality level is closely related to image quality and the lower the degree of
compression, the higher the image quality; however, this also causes the volume of data in the
image file to increase. The default setting is either "2" or "Medium".
Redundant array of independent disks (RAID)
This is referred to as a RAID disk array and is a means by which multiple hard disks can be
combined to be utilized like a single disk and reliability and processing speed can be
increased. Although there are seven different types of RAID ranging from RAID 0 to RAID 6,
only RAID 0, 1, 5 and combinations of these types are actually used.
Resolution
Resolution is the scale used to express the degree to which a screen is clear or blurred. Both
horizontal resolution and vertical resolution are indicated using actual numbers and are also
employed as scales for representing camera performance. In fact, horizontal resolution is
generally utilized to compare performance. It can be said that the higher number, the better
performance of camera. Ordinarily, a televised TV broadcast with fairly good horizontal
resolution has a resolution of around 330 TV lines.
Real-time transport protocol (RTP)
This is a transmission protocol used for streaming playback of sound or images. In UDP-type
protocols, for which packet-loss countermeasures, transmission time guarantees, etc. are not
implemented, effective bandwidth and delay time are usually sent to the server via RTCP. The
server adjusts the quality of the data to be sent via RTP according to the transmission status
information it has received and then sends the data.
Smear
This is a phenomenon in which vertical streaks appear above and below brightly lit spot lights
or objects in images with especially high luminance. When an excessive amount of light
enters a solid-state image device, an unnecessary electric charge occurs in the vertical
transfer section, thereby causing this phenomenon.
Simple network management protocol (SNMP)
This is a protocol used to form a network management system on a TCP/IP network. There is
a manager and an agent; the manager inquires about network management information and
the agent responds to these inquiries. The manager function is performed by an exclusive
SNMP manager software program and the agent function is carried out by
telecommunications equipment such as a router or Switching-Hub.
Transmission control protocol (TCP)
This is an OSI reference model transport layer protocol that is utilized as a standard on the
Internet. Although TCP is highly reliable due to the fact that it has a retransmission control
mechanism, it has a low transmission speed.
Transmission control protocol/Internet protocol (TCP/IP)
This is a standard Internet protocol that is comprised of a protocol that specifies a
communications software program (application) and then establishes a data transmission
channel (TCP), and a protocol related to communication pathways (IP).
User datagram protocol (UDP)
This is utilized as an OSI reference model transport layer protocol. Although UDP has low
reliability due to the fact that it has no retransmission control mechanism, it has a high
transmission speed.
Uninterruptible power supply (UPS)
This is a device that can be used to supply power for a fixed period of time in the event of an
unexpected power outage so that PCs can be shut down safely.
Voice over IP (VoIP)
This technology makes it possible to place telephone calls over an IP network. Although the
internet can be used as a phone line, the call quality of internet phone is generally not very
high because transmission speed and delay cannot be guaranteed.
Wide dynamic range function
This refers to a function through which various processes are performed, thereby making it
possible to capture clear images even when there is extreme backlighting.
Author, Director and Editor: Kazufumi Namise, Kenji Nikki
Local area network (LAN)
This refers to the connection of multiple computers or peripherals over a network within a
confined area such as the same building, site or organization. Correspondingly, a computer
network that goes beyond buildings or sites to connect LAN between remote locations is
referred to as a wide area network (WAN).
Lens mount
Cameras have different types of lens sockets including C mount, CS mount and bayonet
mount. C and CS mounts are screw-type mounts; C mounts have a flange focal length of
17.526 mm and CS mounts have a flange focal length of 12.5 mm. Bayonet mounts are often
employed in three-chip cameras and this type of mount conforms to the standard for studio-
use cameras.
Line lock
This is a function that synchronizes the camera's vertical synchronizing signal with the
frequency of the commercial power supply. The function can be used to reduce hum noise
induction to the video signal and illumination flicker. If the image output of several cameras is
switched, vertical synchronization disturbance, which occurs on the screen, can be
prevented.
Media access control (MAC) address
This refers to the unique address allotted to all devices connected to LAN, and is represented
as a 16 base, 12 digit, 48-bit (6 byte) address. The high 3 bytes are assigned by the device's
vendor ID and the low 3 bytes are assigned by a unique number from the vendor.
Minimum illumination
The minimum level of object illumination required for security cameras is referred to as
"minimum illumination". The lower this value is, the higher the sensitivity of the camera. This
value also serves as an indication of how dark of a place shooting can be carried out in. It
should be duly noted that minimum illumination changes depending on both the F number of
the lens being used and the reflectance of the object. If a security camera is used at a level
close to the minimum illumination, the image may become blurred. Since this is undesirable,
we recommend that sufficient illumination be used.
Motion detection
This is a function that alerts you with an alarm when there is motion in the image.
Motion-JPEG
This is a technology that makes it possible to decompress still JPEG images at a high speed
as well as make them appear as if they are moving by showing them in succession. This can
also refer to the moving image data or the codec that performs compression/decompression.
Unlike MPEG data, which only records differential information between the frames of a
moving image, Motion-JPEG makes it possible to edit any portion of a moving image because
each frame is saved as a still image.
Moving picture coding experts group/
Moving picture experts group (MPEG)
There are numerous standards such as MPEG-1, MPEG-2 and MPEG-4 for technologies
utilized to compress digital moving images. MPEG-1 takes into account storage/playback on
storage media such as CD-ROM and has playback quality equivalent to that of VTR. MPEG-2
takes into consideration usage with broadcast media and has playback quality equivalent to
that of HDTV. MPEG-4 is aimed at the distribution of low-quality images at a high compression
rate through the use of a slow-speed network.
Multicast
This is a method that makes it possible to simultaneously transmit the same data to several
specified computers.
Network address port translation (NAPT)
Network address port translation is the official name for IP masquerade. This technology is
used to effectively utilize scarce IP address resources by converting IP addresses and
TCP/IP port numbers between two networks (WAN/LAN).
Network address translation (NAT)
This technology makes it possible to mutually convert private and global IP addresses as well
as transparently access these addresses. NAT functions are incorporated in a router.
Network time protocol (NTP)
NTP is a time information protocol that is used as a standard on the Internet. SNTP is a
simplified version of NTP.
OLE control extension (OCX)
OCX is a software component based on OLE2.0. Although the correct term is OLE control, the
filename extension is "OCX", and therefore it is primarily referred to as OLE control extension.
It is also called Active X.
OSI reference model
This model shows the protocol guidelines and its functions are separated into a total of seven
layers. The upper layer of the model, which is closest to human interface, consists of three
layers: the application layer, the presentation layer and the session layer. The lower layer,
which is used for transmission purposes, consists of four layers: the transport layer, the
network layer, the data link layer and the physical layer.
Personal computer memory card international association (PCMCIA)
PCMCIA stands for personal computer memory card international association and regulates
cards and slots related to PC cards.
Port address translation
This technology is used to convert IP addresses and TCP/UDP port numbers between two
43
Glossary
JVC Video Surveillance Products 2006-2007
http://pro.jvc.com
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