LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> BMW >> 2007 >> Z4 2D Convertible, Automatic >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> Advanced Safety Electronics - Overview >> Advanced Safety Electronics (ASE) >> System Components >> Byteflight
April 5, 2026: LEMON Manuals is launched! Read the announcement.

System Components: Byteflight

The increasing complexity of in-car electronics and the growing amount of sensors, actuators and electronic control units place higher demands on the high-speed data communication protocols.

None of the communication solutions available until now have been able to fulfill all these demands.

BMW together with several semi-conductor companies have developed byteflight  a new protocol for safety-critical applications in automotive vehicles.

The byteflight  is the bus system used exclusively for the ASE System (Intelligent Safety Integration System). This ASE Sytem of the E85 contains the Safety and Information Module (SIM) and 4 additional satellite control modules.

The ASE System is a bus composed of Fiber Optic cables and control modules arranged in a STAR pattern with the SIM at the center of the system.

Since the byteflight  is a star structure as opposed to the continuous ring structure of the MOST bus, the fiber optic cables carry the data bi-directionally, a single fiber optic cable connects each satellite directly to the SIM.

Each satellite contains a transmitter/receiver module for receiving and sending data to the SIM. The SIM contains 4 transmitter receiver modules for communication with the satellites simultaneously.

All information from each satellite is made available to every other satellite by the SIM.

NOTE: Repairs to the byteflight fiber-optic cable are not permitted. Damaged cables must be replaced with new fiber optic cables.
Fig 1: Identifying ASE Flight Bus System
G03397748Courtesy of BMW OF NORTH AMERICA, INC.

Because of the use of byteflight  , the ASE system has the following advantages: