Depending on the grade of safety relevance, in driver assistance systems safety aspects need to be considered. For those applications, potential communication failures such as
- Failure of communication peer
- Unintended message reception
- Message loss
- Message corruption
- Message delay
need to be detected safely .
To this purpose, an adequate safety software layer concept can be introduced. The safety layer is added to one or the other application (Fig. 3). The counter measures are, for example
- CRC (cyclic redundancy check)
- Sequence counter
- Message length
- Timeout detection
Fig.3: Safety Layer Concept Example
The feasibility of this concept has already been proven by corresponding studies in cooperation with the German TÜV . MOST150 supports the safety layer concept to enable fail-safe application up to SIL level 3 according to IEC 61508 and ASIL C according to ISO 26262 .
The latest generation MOST150 already fulfils the requirements to the greatest possible extent. And, as in an infotainment system, the functional system model can be used for internal device communication, so for the application it does not matter whether the communication partner is sitting in the same control unit or connected across the network. Moreover, the network can be mixed with “normal” network nodes without a safety layer.
Robustness and Maturity
Today, MOST Technology is proven as robust in over 115 car models on the road. The latest generation of the MOST Specification incorporates the lessons learned.
For the third generation of MOST, reference implementations  have been realized and several OEMs have given their approval as the technology is mature. SOP for cars with MOST150 will be in 2012.
MOST stands for a system solution approach. It proves as cost efficient.
- The inherent synchronicity on the network level lowers the requirements on the component level and saves resources.
- Standardization of MOST provides reuse of the function blocks, which are sets