Simple synchronisation for open sound control

Clock synchronisation is a mature and important aspect of distributed computing systems. Despite the importance of accurate timing in music, there are relatively few widely applicable synchronisation solutions available to computer music practitioners. In this paper we present a simple OSC-based synchronisation method for wired and wireless applications, which is designed to be easy to apply and is shown to offer accuracy appropriate for fine-grained music applications. The proposed solution relies on a single master sending a synchronisation message to all slaves. Empirical studies with a heterogeneous network of 17 Wi-Fi slaves and 5 Ethernet slaves demonstrate that each homogeneous group is able to achieve a relative synchronisation accuracy of 166 us and 100 us respectively, offset from the master time by their respective network latencies. An acoustic localisation system is implemented to demonstrate an application that requires both accurate synchronisation and benefits from wireless connectivity. The system is shown to precisely locate a sound source with a standard deviation of 1.8 mm.