ANNEX I CRequirements for construction, testing, installation, and inspection
Appendix 12
POSITIONING BASED ON GLOBAL NAVIGATION SATELLITE SYSTEM (GNSS)
4.VEHICLE UNIT WITH AN EXTERNAL GNSS FACILITY
4.2.Communication between the external GNSS facility and the vehicle unit
4.2.1Communication Protocol
F1GNS_20The GNSS Secure Transceiver shall use a memory to store the data and be able to perform at least 20 millions write/read cycles. Apart from this aspect, the internal design and implementation of the GNSS Secure Transceiver is left to the manufacturers.
The mapping of record numbers and data is provided in Table 1. Note that there are five GSA sentences for the GNSS constellations and Satellite-Based Augmentation System (SBAS).