Chapter 1 Introduction: intelligent vehicular communications

1.3.3
SOCIETY OF AUTOMOTIVE ENGINEERS (SAE)
The recent development of SAE J2678 2015 provides recommendations for Navigation and Route 
Guidance Function Accessibility while driving. This initiative endorses practice and implementation of 
navigation and route management. SAE J2365 2015 states recommendations for calculating time for 
in-vehicle navigation and route guidance. This standard suggested practices on both original equipment 
manufacturer (OEM) and aftermarket route-guidance and navigation system functions for passenger 
vehicles by providing a method on time required to compute the navigation-related mission. SAE 
J2400 deals with the human factor in Forward Collision Warning (FCW) Systems, emphasizing user-
interface requirements. This SAE standard provides an FCW operator interface, as well as necessities 
and test approaches for systems capable of warning drivers of rear-end collisions.
1.3.3.1 Japan’s Initiatives
In Japan the bands 58,355,840 and 58,455,850 MHz were allocated for uplink and 57,905,795 and 
58,005,805 MHz for downlink for the Association of Radio Industries and Businesses standard ARIB 
STDT55. The system relies on road architecture, as with DSRC, and provides ETC service. The stan-
dard uses ASK modulation for a data rate of 1 Mbps with 8-slot TDMA/FDD to provide service for 
a maximum of eight cars within a range of 30 m. Currently a new standard (ARIB STDT75) is being 
developed [3]. These systems can be regarded as the first generation of vehicular communications. The 
different standards and frequencies hindered the implementation of ITS systems since each country has 
its own specifications and operating systems. Moreover the low data rates and short distances were only 
suitable for a limited number of applications.

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