Specifications

Appendix
N35110 Installation User Manual
72
JPEG (Joint Photographic Experts Group).Together with the GIF file format, JPEG is an
image file type commonly used on the web. A JPEG image is a bitmap, and usually has the file
extension ‘.jpg’ or “.jpeg.” When creating a JPEG image, it is possible to configure the level of
compression to use. As the lowest compression (i.e. the highest quality) results in the largest file,
there is a trade-off between image quality and file size.
kbit/s (kilobits per second) is a measure of the bit rate, i.e. the rate at which bits are
passing a given point. See also Bit rate.
LAN (Local Area Network) is a group of computers and associated devices that typically
share common resources within a limited geographical area.
Lux is a standard unit of illumination measurement.
MAC address (Media Access Control address) is a unique identifier associated with a
piece of networking equipment, or more specifically, its interface with the network. For example,
the network card in a computer has its own MAC address.
Mbit/s (Megabits per second) is 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.
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.
MPEG-4 is a group of audio and video coding standards and related technology. The
primary uses for the MPEG-4 standard are web (streaming media) and CD distribution,
conversational (videophone), and broadcast television. Most of the features included in MPEG-4
are left to individual developers to decide whether to implement them or not. This means that there
are probably no complete implementations of the entire MPEG-4 set of standards. To deal with
this, the standard includes the concept of "profiles" and "levels", allowing a specific set of
capabilities to be defined in a manner appropriate for a subset of applications.
Multicast is a bandwidth-conserving technology that reduces bandwidth usage by
simultaneously delivering a single stream of information to multiple network recipients.
Network Time Protocol (NTP) is a protocol for synchronizing the clocks of computer
systems over packet-switched, variable-latency data networks. It is designed particularly to resist
the effects of variable latency by using a jitter buffer.
NTSC (National Television System Committee) 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. See
also PAL.