This part of ISO 17575 defines the content, semantics and format of the data exchange between a Front End (OBE plus optional proxy) and the corresponding Back End in autonomous toll systems. It defines the data elements used to specify and describe the toll context details. Context data are transmitted from the Back End to the Front End to configure it for the charging processes of the associated toll context.
In ISO 17575, context data is the description of the properties of a single instance of an electronic fee collection (EFC) context. This single instance of an EFC context operates according to one of the basic tolling principles such as— road section charging,— area charging (according to travelled distance or duration of time), and— cordon charging.EFC context data comprise a set of rules for charging, including the description of the charged network, the charging principles, the liable vehicles and a definition of the required contents of the charge report. This set of rules is defined individually for each EFC context according to local needs.The following data and associated procedures are defined in this part of ISO 17575:— data providing toll context overview information;— data providing tariff information (including definitions of required tariff determinants such as vehicle parameters, time classe, etc.);— data providing context layout information;— data providing reporting rules information.This part of ISO 17575 also provides the required definitions and data specifications to be applied when one single toll context is spilt inot more than one toll context partitions. This is applicable to cases where one EFC scheme and the rules applied cannot be described with a single set of context data.Annex A provides the data type specification using ASN.1 notation.The protocol implementation conformity statements (PICS) proforma are provided in Annex B.