1. A static priority assignment algorithm (AGP) with limited priority levels is developed.

2. The article introduces the transmission mechanism and priority assignment method of the message on CAN bus.

3. The priority assignment problem was formulated as a combinatorial optimization problem which was targeted to achieve maximal fairness, and a solution was also provided.

4. Two advancements include CPU shielding and on-the-fly priority assignment .

5. Deadline monotonic ordered saturated assignment is proved to have the least priority levels, which is much quicker than those tradional priority assignment algorithms.

6. Thus we must resolve the academic and technical problems about the data models, transaction models, and priority assignment and schedule strategies of the mobile real-time transactions.

7. This paper present an improved method for analyzing the schedulability of periodic task sets under Rate Monotonic(RM) priority assignment.