Distributed slot synchronization (DSS): a network-wide slot synchronization technique for packet-switched optical networks

Distributed slot synchronization (DSS) is a network-wide packet synchronization technique which coordinates node transmissions so that packets arrive aligned to one another at a reference point in the network, independent of propagation delays. DSS was developed for use in the contention resolution with delay-lines (CORD) project, a DARPA-funded 2.5 Gb/s/λ, wavelength division multiplexer (WDM) optical packet-switched network testbed. In this implementation, it was experimentally demonstrated that the DSS system, operating with 80 MHz control logic, achieves a packet arrival jitter of less than 13 ns with 12 km node spacings. DSS was also shown to be robust against noise and node failure or fiber breaks. The technique is data rate and format independent and can be used in other star, extended ring, or tree-and-branch network architectures for metropolitan area network (MAN) and access applications