Some of the mystique generated by Siemens marketing around synchronous technology is that it is heavily protected by patents. Maybe.
I haven't found any record of patents pending in the USA, but perhaps the patents were/are taken out in the European Union.
If the patents haven't been registered by now, it may be too late for Siemens PLM Systems, for the USPTO is saying it might not accept software patents anymore -- with an emphasis on the word "might."
The [US] Supreme Court has repeatedly ruled that abstract concepts and mathematical algorithms are not patentable.
You can read more on the uncertain future facing patents on software at Patent Office finds voice, calls for software patent sanity by Timothy B. Lee on ars technia.