Distributed slot synchronization (DSS) is a network-wide packet synchroniza
tion 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/lambda, wavelength
division multiplexer (WDM) optical packet-switched network testbed, In thi
s implementation, it was experimentally demonstrated that the DSS system, o
perating with 80 MHz control logic, achieves a packet arrival jitter of les
s than 13 ns with 12 km node spacings. DSS was also shown to be robust agai
nst 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-an
d-branch network architectures for metropolitan area network (MAN) and acce
ss applications.