Data transmission system and occupant protection device

An occupant protection device provided in a vehicle, including:

• a protecting unit for protecting an occupant of the vehicle;
• a plurality of satellite sensors, each of the satellite sensors having
• an impact measuring unit for measuring an impact applied to the vehicle, and
• a sending unit for sending a signal representing the impact measured by the impact measuring unit;
• and
• a start controlling unit for controlling start of the protecting unit based on the signal sent by the sending unit,
• the sending unit comprising:
• converting means for converting the signal having a predetermined range to generate a digital value with a resolution of K bits;
• and
• compressing means for compressing the digital value generated by the converting means to generate a digital signal of L bits, wherein L is smaller than K,
• wherein the sending unit sends to the start controlling unit the digital signal generated by the compressing means,
• wherein the compressing means includes determining means for determining whether the digital value generated by the converting means is within a given range,
• wherein, when the digital value is outside the given range, the digital signal of L bits is generated by dividing the digital value by a first divisor,
• wherein, when the digital value is within the given range, the digital signal of L bits is generated by dividing the digital value by a second divisor, and
• wherein the first divisor is 2(K−L), while the second divisor is less than 2(K−L).