- These are standards set by the ITU-T regarding methods for the determination of transmission
P.800 An ITU Recommendation regarding methods for the subjective determination of transmission quality. This recommendation is the basis of a wide range of subjective quality and intelligibility testing. These tests are offered by HEI.
P.910 An ITU Recommendation regarding methods for the subjective assessment of video transmission quality for multimedia applications, tests offered by HEI.
P.920 An ITU Recommendation regarding interactive test methods for the quality assessment of audio and visual communications, tests offered by HEI.
- IEEE standard providing the overview and architecture of: Integrated Services (IS) LAN: IEEE 802.9 Isochronous services with Carrier sense multiple access with collision detection (CSMA/CD) Media Access Control (MAC) service. The Iso-Ethernet standard. See also H.322.
- The process of transmitting digital information by means of addressed packets, that include data, call control signals, and error control information, so that a channel is occupied only during the transmission of the packet.
In contrast, data sent using modems occupy a circuit for the entire duration of the transmission, even when no data are actually traveling over the lines. Using packet switching, the various packets of information can travel along different routes on the network, allowing the carrier to optimize its network capacity.
Packet Switched Network (PSN)
- Transmitted data broken into small packets so each can be sent over a different route if there is extensive network
traffic. Can be used to expand communications capability when choices of mediums are
- See "cine loop."
- A range of frequencies passed by a device or network.
Patient Information and Imaging Libraries (PIIL)
- Devices and techniques which store, retrieve and manipulate digital images and patient data.
PC applications as a video input source
- Indicates whether a separate PC application (e.g., PowerPoint, MS Word) can be run on the system during a video conference and sent as the video picture to the far end.
PC applications conferencing
- Describes the ability to run a PC application on one end of a video conference and to share that application with the PC at the other end of the video conference. This computer sharing application allows the monitors and keyboards to simultaneously interact with the computer program while in a conference. It has use primarily in administrative applications when working in a financial spreadsheet or database, and in distance learning environments when using educational software.
PC platform for data/applications access and storage
- Indicates if a personal computer (PC) is integrated into the system and is available for use by PC applications.
- Attachments to videoconferencing systems to augment their communications or medical capabilities. Examples include: electronic stethoscopes, oto-/ophthalmoscopes, dermascopes, graphic stands, and scanners.
Peripheral diagnostic scopes
- Analog cameras mounted within specific diagnostic tools such as a dermscope, otoscope, ophthalmoscope, dental probe, as well as an electronic stethscope, which can be attached to the video teleconferencing systems to provide higher resolution video and still imagery during a telemedicine consultation.
- In a data processing system, any equipment, distinct from the central processing unit, which may provide the system with outside communication or additional facilities
Phase Alteration by Line (PAL)
- The broadcast video standard used in West Germany, Great Britian and most Western European nations. By reversing the relative phase of the color signal components on alternate scanning lines, this system avoids the color distortion that appears in NTSC. Otherwise, PAL closely resembles NTSC. Based on the 50 Hz power system, PAL displays 625 lines interlaced at 50 fields per second (25 frames per second). PAL is incompatible with NTSC or SECAM; conversion between standards is possible.
- "P time 64"
- "P time 64". Synonymous with the ITU H.261 standard.
Picture Archiving and Communication System (PACS)
- An image system that embraces all modalities (X-ray, CT, MR, nuclear medicine, ultrasound) and links users with display workstations over a high speed network to an image server, an archive, printers, and radiology information systems (RISs). Computer-based image management and communications systems for the creation of a totally electronic radiology department.
Picture Element (PEL)
- Picture in picture (PIP)
- PIP allows both ends of the video conference to be viewed simultaneously on a single monitor. Picture in picture swap
- allows the two video pictures to change positions so that the local video fills the largest portion of the screen. On some two monitor systems, PIP allows both live video images to be seen simultaneously on one screen while higher resolution graphic images are seen on the other.
An abbreviation for picture element. The smallest unit of a raster display. A picture cell with specific color and/or brightness. One way to measure picture resolution is by the number of pixels used to create the image. The more pixels an image has, the more detail, or resolution, it can display. The pixel size in a high-end computer monitor's screen (a "1K x 1K monitor") is approximately 0.28 x 0.28 mm. The pixel size for diagnostic teleradiology monitors ("2K x 2K") is much smaller than this.
Plain Old Telephone System (POTS)
- The analog, public switched telephone network in common use throughout the world. Also known as Public Switched Telephone Network (PSTN). Enables voice phone calls and data transmission of up to 33.6 Kbps, as well as limited videoconferencing.
Point of Presence (POP)
- The point at which an interexchange carrier's circuits connect with local circuits for transmission and reception of long distance phone calls. A switching site maintained by a long distance carrier in a LATA. Local exchange carriers will route long distance calls from their central office to the POP of the appropriate long distance carrier.
Point-to-Point (PPP )
- Internal telephone systems located on the premises of many large offices. The switch located on the customer's premises primarily establishes voice graded circuits over tie lines between individual users and the switched telephone network (PSTN).
- European name for PRI.
- Determines how many predefined camera positions can be set. Presets are useful for rapid changes in camera position - for example, to quickly move from a close up of a patient to a larger view of both the patient and the physician.
Primary Rate Interface (PRI)
Primary user interface device
- Indicates what type of device is used to control the video conferencing system. Hardwired and wireless, keyboard, mouse, and touchscreen options each have advantages and disadvantages. The user should seriously consider in what setting and for what application the system will be used to determine which is the preferred interface.
- A direct channel created between two institutions.
- An R&D Component project of the Medical Advanced Technology Management Office designed to explore technology to increase the personal productivity of health care workers (i.e., Physicians, Nurses, Techs, Ancillary Personnel). Technology investigated includes handheld/wireless systems, Exploring the Internet for uses in the DoD, and the Meditag, a nearly indestructible storage device that can make nearly instant access to up to 90megabytes of information a practical reality.
- The formal rules governing the exchange of information in a communication link including format, timing, sequencing and error control.
- Public Switched Telephone Network (PSTN)
- A network established and operated by communication common carriers or telecommunication administrators for provision of circuit switched, packet switched and leased line circuits to the public.