Standard for Message Sets for Vehicle/Roadside Communications
|Publication Date:||26 June 1999|
Those characteristics of a dedicated short-range communications (DSRC) system that are independent of the Physical and Data Link Layers (ISO model Layers 1 and 2) are specified. The required and optional features of the roadside equipment (RSE) and the onboard equipment (OBE) are specified. In addition, the Applications Layer (ISO model Layer 7) services and protocols, the RSE resource manager, the corresponding OBE command interpreter, and the application-specific
The electronic toll and traffic management (ETTM) field is rapidly evolving, and ETTM systems across North America use a variety of incompatible dedicated short-range communications (DSRC) products. Several mainline screening systems for commercial vehicle operations (CVOs) are now in operation and likewise use incompatible data definitions. In addition, the acceptance of the ASTM Standard for DSRC Layers 1 and 2 will create the potential for significant interference between radio frequency (RF) compatible systems.
The lack of standard message sets, lower layer protocols, and transponder resource definition threatens to postpone the deployment of DSRC systems, a technology critical to the intelligent transportation systems (ITS) marketplace. This standard consolidates and builds upon previous application-specific
While this standard has been developed to ensure efficient operation when used in conjunction with the ASTM Layer 1 and Layer 2 standards, it is not limited to that application. This standard may be use in conjunction with a variety of lower layer protocols, including both RF and other communications media.
This standard is applicable to dedicated short-range communications (DSRC). Within the overall context of DSRC operations (illustrated in Figure 1), this standard governs the communications protocols above the open systems interconnection (OSI) data link layer for the DSRC wireless interface. This standard does not specify the interface between the transponder and other pieces of onboard equipment (OBE) (identified as "5" in Figure 1), nor does it specify the interface between the roadside equipment (RSE) and the back office equipment (BOE) that hosts an intelligent transportation systems (ITS) back office application (BOA) (identified as "1" in Figure 1). However, to obtain desirable levels of DSRC performance, it is essential that those interfaces be defined in a manner that is consistent with this standard.
Interface 2 in many systems may be the interface between the application layer and lower layer service. Nothing precludes combining a vehicle-to-roadside communication (VRC) controller, a reader, and an antenna into a single piece of equipment.
These communications protocols have been specified by defining the message set and data dictionary, the low-level commands used to control transponder resources and thereby access such messages, and the OSI application layer services used to connect the upper interface elements with the OSI data link layer elements. This standard also specifies the resources that may be present on a transponder and the means by which the RSE shall control those resources.
Product compliance with this standard shall be verified based upon tests of Interfaces 1 and 4 shown in Figure 1. Internal interfaces such as 2 are at the discretion of the equipment vendor and shall not be considered when determining product compliance.