22.2893GPPMobile communication system for railwaysRelease 17TS
For the purposes of the present document, the terms and definitions given in 3GPP TR 21.905  and the following apply. A term defined in the present document takes precedence over the definition of the same term, if any, in 3GPP TR 21.905 .
Area traffic capacity: total traffic throughput served per kilometer along a rail line.
CCTV: Closed-circuit television, also known as video surveillance, is the use of video cameras for monitoring and recording people, animals and objects in different places, such as in vehicles and stations.
CCTV offload: Transfer of video surveillance data archives from train to ground through the wireless connection between mobile communication unit in the train and ground communication units located at the depot and at the stations and/or stops.
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.
End-to-end latency: the time that takes to transfer a given piece of information unidirectional 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.
Inter-carriage link: Wireless connection between the carriages of the train.
Reliability: in the context of network layer packet transmissions, percentage value of the amount of sent network layer packets successfully delivered to a given system entity within the time constraint required by the targeted service, divided by the total number of sent network layer packets.
Survival time: the time that an application consuming a communication service may continue without an anticipated message.
Transfer interval: time difference between two consecutive transfers of application data from an application via the service interface to 3GPP system.
For the purposes of the present document, the abbreviations given in 3GPP TR 21.905  and the following apply. An abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in 3GPP TR 21.905 .
CCTV Closed-circuit television
MTTC Mass-transit train control