computer or network that is required to meet a standardized communications interface over a fixed-point communications network, regardless of whether it is the only system within the building or just one of many, or even if it is located in the field

process or program using the communications stack

detector that detects vehicles and traffic characteristics based on the state of the occupancy using methods such as loop or magnetic detectors

computer or application which requests and accepts data from a server computer or application using some kind of protocol

terminal units controlled or monitored by a traffic management centre

NOTE Roadside modules are usually installed at the roadside arena.

roadside equipment that communicates with the roadside units such as the signal controllers and the in-vehicle units

roadside equipment that controls the lighting timings of traffic lights

the invehicle equipment that transmits/receives information to/from the Roadside Communication Units and, in some cases, outputs information on its screen, etc.

system or device which was the source for all of the information in the data packet

NOTE In many cases, this will be the same as the sender, but could be different. For example, a bridge (or proxy agent) may translate between protocols; in this case the bridge (or proxy agent) would be the sender, while the system generating the data would be the origin.

the central system that controls the functions of traffic data collection, signal control, and information service based on collected data, etc.