Video Conferencing Terminology [N - Q]

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• » Network [top]
  A network is a group of computer or telephone stations connected together by hardware and software.
   
• » NTSC (National Television Standards Committee) [top]
  The NTSC represents the American and Japanese standard television video signal format of 525 picture lines and a 60Hz field frequency.
   
• » Packet [top]
  Packets are sequences of digitized information. Network traffic is divided into packets. Each packet has a header with source and destination data, the data content itself, and error-checking code. The packets are then sent to their destination computer over the network.
   
• » Packet Switching [top]
  This is the process of subdividing data into packets, allowing for easier transmission of the data. The individual packets are then sent, often following differing routes to their destination. After they have all arrived, they are recompiled into the original message. X.25 is the international standard.
   
• » PAD (Packet assembler/dissembler) [top]
  PADs are hardware devices that allow simple devices (usually data terminals not optimized for packet switching) to use a packet switching network. PADs assemble data into transmission ready packets and disassemble the packets on arrival. 
   
• » PAL (Phases Alternate Line) [top]
  Europe’s television video signal standard is known as PAL. PAL uses 625 picture lines and a 50Hz field frequency, and is incompatible with NTSC. 
   
• » Pan [top]
  Pan is short for panorama, referring to the movement of a camera horizontally from side to side.
   
• » Pixel [top]
  Pixels are the smallest possible display unit of visual information available for building a graphical image. 
   
• » Point-to-point [top]
  Unlike a multipoint communications links, point-to-point connects two and only two stations.
   
• » POTS (Plain Old Telephone Service) [top]
  POTS use twisted-pair copper wires used on conventional analogue narrowband telephone lines, and have been in use since the beginnings of the telephone system in the late 1800s. POTS became PANS (pretty advanced network services) in the 1980s, with additional features like voicemail, caller ID, and call waiting.
   
• » PPP (Point-to-point Protocol) [top]
  Point-to-point Protocol is the primary method used in establishing a direct connection between two devices on a network (usually a computer and the Internet). It is a communication protocol between computers using one of several methods: usually TCP/IP, telephone lines, or ISDN.
   
• » Protocol [top]
  Protocols are standard procedures used for regulating data transmission between computers. Protocols exist to minimize errors during the exchange of data.
   
• » PTZ (Pan-Tilt-Zoom) [top]
  Indicates the ability or functionality of a video camera to pan, tilt, and zoom. 
   
• » QCIF (Quarter Common Intermediate Format) [top]
  Arrived at by the ITU, QCIF is a video format created to govern the transmission of video signals over ISDN. QCIF’s specs are 176 luminance pixels on each of 144 lines. 
   
• » QQCIF (Quarter Quarter Common Intermediate Format) [top]
  This format regulates both ISDN and POTS transmission, and specifies 88 luminance pixels on each of 77 lines.