AV Production: the process by which audio and video content are combined in order to produce media content. This could be for live events, media production, conferences or other professional applications. Clock Synchronicity: The maximum allowed time offset within a synchronisation domain between the master clock and any individual UE clock. The maximum allowed time offset within the fully synchronised system between UE clocks. Compressed Video: a means of making video file or stream sizes smaller to meet various applications. Different applications have different compressions methodologies applied.

• Mezzanine compression: low latency and non-complex compression applied to a video signal in order to maintain the maximum amount of information whilst reducing the stream size to allow for the available bandwidth.
• Visually lossless compression: the maximum amount of compression that can be applied to a video signal before visible compression artefact appear.
• Highly compressed: use of compression to distribute content over very low bandwidth connections where the content is more important than the quality of the image.

Communication service availability: percentage value of the amount of time the end-to-end communication service is delivered according to an agreed QoS, divided by the amount of time the system is expected to deliver the end-to-end service according to the specification in a specific area. Communication service reliability: ability of the communication service to perform as required for a given time interval, under given conditions. Cue/Talkback: Audio messages sent from broadcast centre to location usually to instruct a presenter when to speak. This is not audible in the broadcast audio. End-to-end Latency: the time that [it] takes to transfer a given piece of information from a source to a destination, measured at the communication interface, from the moment it is transmitted by the source to the moment it is successfully received at the destination. Isochronous: The time characteristic of an event or signal that is recurring at known, periodic time intervals. Imaging System Latency: The time that takes to generate an image from a source, to apply a certain amount of processing, to transfer it to a destination and then to render the resulting image on a suitable display device, as measured from the moment a specific event happens to the moment that very same event is displayed on a screen. In-Ear-Monitoring (IEM): A specialist type of earphone usually worn by a performer in which an audio signal is fed to a wireless receive device and attached earphone. Media Clock: Media clocks are used to control the flow (timing and period) of audio / video data acquisition, processing and playback. Typically, media clocks are generated locally in every mobile or stationary device with a master clock generated by an externally sourced grand master clock (currently GPS but transitioning to 5G in future). Mouth-to-ear Latency: End-to-end maximum latency between the analogue input at the audio source (e.g. wireless microphone) and the analog output at the audio sink (e.g. IEM). It includes audio application, application interfacing and the time delay introduced by the wireless transmission path. Multi-Cam: The use of two or more cameras in an outside broadcast which can be cut between, important considerations are colour imagery, timing, framing and picture size and frequency. Outside Broadcast: A production where content is being acquired away from the broadcast centre and controlled from the location. Generates output for broadcast which may be sent back to the broadcast centre for inclusion into a programme or for onward distribution. Radio Microphone: A microphone that uses a wireless connection to transmit either an analogue or digital audio channel on a dedicated radio frequency or multiplex to one or more dedicated receivers which then output an audio signal suitable for onward processing. Survival time: the time that an application consuming a communication service may continue without an anticipated message. Uncompressed Video: Uncompressed video is digital video that either has never been compressed or was generated by decompressing previously compressed digital video. Video, imaging and audio: The means of digital capture, transmission and storage of still and moving pictures and sound for professional use.