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Federal Communications Commission (FCC)
A US body regulating, approving and licensing radiated electromagnetic signals including broadcasting and telecommunications.

Fiber Distributed Data Interface (FDDI)
A high bandwidth networking scheme that uses fiber optic cable. The topology relies on two rings for redundant 100Mbps transmissions. FDDI uses a token passing access method similar to token ring which results in a more deterministic performance than the contention-based Ethernet. FDDI-2 is a second generation of FDDI networks that support Isochronous channels that may enable voice and video over these networks.

Fiber Optic Transmission System (FOTS).
With little transit time delay and very low bit error rate, the superior method to transmit digital video signals.

Film Digitizer
A device that allows scanning of existing static images so that the images can be stored, manipulated or transmitted in a digital form.

Firewall
A computer connected both to the Internet and the local HIN that prevents the passing of Internet traffic, in the form of IP packets, to the internal hospital network. Provides an added layer of protection against 'hackers'. There are two kinds of firewalls: external, which protect all hospital systems form the outside world, and internal, which protect only selected systems. Firewall disadvantages: it restricts information transfer in both directions, and makes file transfer (ftp) and telnet (remote login) more difficult. See access control, encryption.

Firmware
Data and/or program software for the codec or other electronic device stored in a non-volatile form in a semiconductor memory circuit. For codecs, the firmware is often housed in a plug-in module.

Forced Intraframe Coding
1. In motion video compression, immediately following a significant scene change, the differential, predictive and inter- frame coding aspects are temporarily disabled. The information then transmitted for the first changed frame is derived entirely from within that frame. 2. In motion video compression, static parts of the image are periodically refreshed to mitigate the effects of error build-up in the system.

Forward Error Correction (FEC)
A mathematical technique in which a syndrome is generated and transmitted with data so that, at the receive location, processing of the syndrome along with the data will allow correction of errors caused by the transmission system. Depending upon the FEC technique used and how it is applied, the transmitted codec signals may be made more or less robust in the presence of line transmission errors.

Frame Delete Compression
In H.261 motion video compression, the total discarding of from zero to three consecutive video frames as part of the compression process. Its use depends upon the degree of video motion existing and the aggregate bit rate. Last-resort compression.

Frame grabber
Captures, into a computer, the analog display output of cameras, VCRs, etc. A device that "captures" and potentially stores one complete video frame. Also known as Frame Storer.

Frames per second (fps). See Frame Rate. Frame rate
Frames per second (fps) displayed on a video monitor. A frame rate of 25-30 fps is consider 'full motion' and is what most broadcast video operates at. A frame rate of 15 fps is noticeably 'jerky'. Slower frame rates may be inadequate for gait and motion observations and analysis. See NTSC, PAL, SECAM.

Frame Relay
A service that supports data rates in the range of 56 Kbps to 1.54 Mbps. The Frame Relay circuit often comes in different levels of committed information rates (CIR). A 1.54 Mbps Frame Relay circuit with a 768 Kbps CIR would indicate that you would never drop below 768 Kbps transmission capability, and could burst up to 1.54 Mbps. RBOCs can offer Frame Relay cheaper since they can oversubscribe these circuits to users and share the bandwidth.

Framework for European Telemedicine Services (FEST)
FEST is an European Community (EC) funded project with some 22 partners and associated partners . The main objective is to develop a framework for Telemedicine services.

Freeze-frame
One method of transmitting still images over standard telephone lines. A single image is transmitted every 8 to 30 seconds. This feature is useful in a medical consultation. It allows the consultant to get a well framed and focused still image of a lesion or other item of interest for closer examination. Often images captured from a live video source are of higher resolution than the live video picture and as a result may provide more diagnostic value.

Full Common Intermediate Format ("Full sif", FCIF).
A 352-by-288 video format that is described by the ITU's H.261 specification. A measure of video resolution. Considered by some a requirement of telemedicine video. See QCIF.

Full Duplex
A communication channel over which both transmission and reception are possible in two directions at the same time. A standard telephone line is a full duplex system because people on either end of the connect can simultaneously speak while listening to sounds coming from the other end.

Full Motion Video
A standard video signal that can be transmitted by a variety of means including television broadcast, microwave, fiber optics, and satellite. Full motion video traditionally requires 6 MHz in analog format and 45 Mbps when encoded digitally. Industry agreements are still needed for efficiently mapping advanced digital video streams into ATM and handling the effect of "cell jitter" in applications where video and audio synchronization is crucial. Since 1994 there have been multimedia experiments over MBONE (Multicast backBONE) primarily by NASA and the military. Some form of video compression normally is used to reduce the amount of data and to allow it to be read from disk quickly enough. The time taken for compression can be relatively long; decompression is done in real-time with the picture quality and frame rate varying with the processing power available. Two compression standards discussed with full motion video are H.261 and MPEG. H.261 was developed before 1992 to work with ISDN and support video conferencing.



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