Synchronous Reactive semantics preserving communication buffer sizing mechanisms and buffer indexing protocols are presented. Because these protocols define buffer indices for writers and readers at task activation time, generally they require a kernel-level implementation. In this paper, we present portable implementations for applications with SR semantics under the OSEK OS standard, which is widely used in automotive designs. To meet the one-alarm minimum requirement, an task called dispatcher is constructed to activate all other application tasks. For the CTDBP, the hook mechanism is used to gain atomicity of the termination code for lower-priority readers. Memory requirements are compared quantitatively for different versions of implementations of the SR semantics preserving protocols. Furthermore run time characteristics for different versions of implementations are measured with the use of the PICos18.