Synchronisation conventions in test theories of special relativity

The Mansouri-Sexl class of test theories of special relativity has motivated various experiments to observe or limit the difference between slow clock transport and Einstein synchronisation. These do not constitute tests of the isotropy of the one-way speed of light, since the latter is conventional. We discuss the effects of the conventionality of synchrony in the preferred frame, as well as the laboratory frame, within the Mansouri-Sexl formalism. We also consider the mutual inter-relationships of both synchrony conventions with measurements of the one-way speed of light and of time dilation factors.