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ALIEN HERO INSTRUCTION MANUAL
147
Last Revised 16/10/2013
16. Glossary
Dual Stream:
Dual stream is a technology used to record high resolution video
locally while transmitting a lower resolution stream over the network. The two
streams are generated by the device, with the main stream having a maximum
resolution of 4CIF (1080P HD models) and the sub-stream having a maximum
resolution of CIF.
DVR:
Acronym for Digital Video Recorder. A DVR is device that is able to accept
video signals from analogue cameras, compress the signal and store it on its hard
drives.
HDD:
Acronym for Hard Disk Drive. A storage medium which stores digitally
encoded data on platters with magnetic surfaces.
DHCP:
Dynamic Host Configuration Protocol (DHCP) is a network application
protocol used by devices (DHCP clients) to obtain configuration information for
operation in an Internet Protocol network.
HTTP:
Acronym for Hypertext Transfer Protocol. A protocol to transfer hypertext
request and information between servers and browsers over a network
PPPoE:
PPPoE, Point-to-Point Protocol over Ethernet, is a network protocol for
encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. It is used
mainly with ADSL services where individual users connect to the ADSL transceiver
(modem) over Ethernet and in plain Metro Ethernet networks.
DDNS:
Dynamic DNS is a method, protocol, or network service that provides the
capability for a networked device, such as a router or computer system using the
Internet Protocol Suite, to notify a domain name server to change, in real time (ad-
hoc) the active DNS configuration of its configured hostnames, addresses or other
information stored in DNS.
Hybrid DVR:
A hybrid DVR is a combination of a DVR and NVR.
NTP:
Acronym for Network Time Protocol. A protocol designed to synchronise the
clocks of computers over a network.
NTSC:
Acronym for National Television System Committee. NTSC is an analogue
television standard used in such countries as the United States and Japan. Each frame
of an NTSC signal contains 525 scan lines at 60Hz.
NVR:
Acronym for Network Video Recorder. An NVR can be a PC-based or
embedded system used for centralised management and storage for IP cameras, IP
Domes and other DVRs.
PAL:
Acronym for Phase Alternating Line. PAL is also another video standard used
in broadcast televisions systems in large parts of the world. PAL signal contains 625
scan lines at 50Hz.
PTZ:
Acronym for Pan, Tilt, Zoom. PTZ cameras are motor driven systems that
allow the camera to pan left and right, tilt up and down and zoom in and out.
USB:
Acronym for Universal Serial Bus. USB is a plug-and-play serial bus standard
to interface devices to a host computer.