The eCall system relies on an In-Vehicle System (IVS) consisting of an eCall application, Cellular Network Connectivity (GSM), a Global Positioning System (GPS), Vehicle Connectivity (CAN), and a GSM modem to transmit vehicle information to an emergency call center, e.g. Public Safety Answering Point (PSAP). In the event of a collision or emergency, via an eCall communication session, the IVS transmits to the PSAP a Minimum Set of Data (MSD) which contains vehicle information, for example, vehicle type, current location, previous locations, propulsion storage type, number of occupants, etc.
The European Standard, EN 15722, “Road Transport and Traffic Telematics”, defines MSD using ASN.1, an international standard used to define data structures and encodings. MSD is encoded in ASN.1 Unaligned Packed Encoding Rules (UPER). The reliability and robustness of ASN.1, and the availability of the limited data space for MSD made ASN.1 and UPER an ideal choice for the eCall standard.
OSS Nokalva, a global leader in ASN.1 technology, provides several ASN.1 Tools which can be used by eCall applications to encode an MSD and by PSAP applications to decode it. The feature-rich ASN.1 Tools, optimized for performance and size, support C, C++, Java, and C# programming languages and have been ported to more than 500 platforms, including embedded and custom platforms.
The MSD ASN.1 specification is compiled by the OSS ASN.1 compiler to generate programming language specific structures or classes. The application code for the eCall system fills these structures/classes, calls the OSS ASN.1 runtime codec to encode the MSD to UPER encoding, and sends it to PSAP via the GSM modem in the In-Vehicle System. The PSAP application calls the OSS ASN.1 decoder to decode the MSD in the structures/classes and uses the decoded values for display on the PSAP operator’s console and/or notifying other emergency services.
For more information about the OSS ASN.1 Tools visit. Online documentation for the Tools can be accessed here. If you have any questions about using the OSS ASN.1 Tools in eCall and PSAP applications, please contact info@oss.com.
