Safety issues caused by the integration of the IMA platform and AFDX

The Integrated Modular Avionics (IMA) platform provides partitioning mechanism to allow multiple applications sharing its resources. And in the network domain, Avionics Full Duplex Switched Ethernet (AFDX) introduces the Virtual Link(VL) technology to provide dedicated bandwidth for each package. The IMA platform and AFDX can provide functional isolation and independence separately, while independence will be broken when the IMA platform and AFDX are integrated. The design of the IMA platform and AFDX are separated, some isolation requirements of the host functions may not be implemented in the network domain. Another issue is the the present VL path planing algorithm, such as Shortest-Path or Load-Banlance, is based on the physical characteristics of data flow and pay little attention to the importance of the data, which may result the lose or failure of one physical link may affects multiple safety critical VL. To solve this problem, this paper propose a VL path planning method named VLPP-S with the consideration of the safety requirements. Firstly, the importance of each partition is measured by the severity of the function hosted. Secondly, the importance of each VL is measured by the partitions it connected and the isolation requirements of the partition are recorded, Thirdly, the path of each VL is planed in order to balance the importance of each physical link, and the isolation requirements of each VL are checked to get the path planning result. Finally, different VL path planning methods are compared, VLPP-S propoed by this paper is more effective to meet the isolation requirements then VL-Shortest-Path and VL-Load-Banlance.