 As the result, IEBus becomes a "de facto standard" of car audio in Japan.Regarding the "Domestic Digital Bus (D2B)", it is re-defined as "D2B Optical" by Mercedes-Benz independently.As for Japanese "Home Bus System (HBS)", it is defined in 1988 as "Home Bus System Standard Specification, ET-2101" by JEITA and REEA (Radio Engineering & Electronics Assiation) in Japan.