An optical access network includes a first ring and a second ring
communicating optical signals in opposite directions. The network also
includes an access node coupled to both rings that adds traffic in a
first wavelength of a first optical signal communicated on the first
ring. Furthermore, the network includes a hub node coupled to each ring
and coupled to an optical core network. The hub node receives the first
optical signal, forwards a first copy of the signal to a first wavelength
blocking unit that terminates the traffic in the first wavelength, and
forwards a second copy of the signal to a first network interconnection
element that forwards the traffic in the first wavelength to the core
network. Furthermore, upon detection of an interruption of the traffic in
the first wavelength on the first ring, the access node adds the traffic
in a second wavelength of a second optical signal communicated on the
second ring. In addition, the hub node receives the second optical
signal, forwards a first copy of the signal to a second wavelength
blocking unit that terminates the traffic in the second wavelength, and
forwards a second copy of the signal to a second network interconnection
element that forwards the traffic in the second wavelength to the core
network.