Traffic engineers, exploring wireless roadside data acquisition systems, have many backbone network options to consider. To optimise their performance, these systems must be connected to a new type of smart remote controller (SRC). This article answers some key questions about wireless data collection, lists relevant radio network technologies, and explains how to gather roadside data using SRCs. The key questions to address are: (1) why a remote wireless Intelligent Transport System (ITS) data collection capability is needed; (2) how raw data needs are affected by this; (3) what happens when a wireless data collection station needs to be relocated; and (4) whether radio time charges will make a specific application too expensive. The design of ITS systems must advance from central to distributed processing, just as computer systems in general have progressed already. The alternative transmission technologies for ITSs include analog cellular, CPDP, spread spectrum, radio modems, and satellite. The fundamental principles to be used include photovoltaic autonomy, power conservation, real-time clock, password protection, system health monitoring and reporting, multiport connectivity, remote parameter set-up, reporting by exception, variable message formatting, alarm reporting, and relay output control.
Abstract