Low-loss, efficient hub ring networks and methods for their use

A low-loss two-ring hub network system comprising:

• a. a plurality of OADMs including each, for each ring, a dynamic DROP section for dropping a plurality of wavelengths from said ring, and a fixed ADD section for adding the same plurality of identical wavelengths to said ring,
• b. means to provide through traffic that includes wavelengths other than said plurality dropped in said DROP section, and
• c. means to combine said through traffic wavelengths and said plurality of added wavelengths, whereby the need of extinguishing wavelengths in the system is removed.

A low-loss two-ring hub network system comprising:

• a. a plurality of dynamic OADMs including each, for each ring, a dynamic DROP section for dropping a plurality of wavelengths from said ring, and a dynamic ADD section for adding the same plurality of identical wavelengths to said
• b. means to provide through traffic that includes wavelengths other than said plurality dropped in said DROP section, and
• c. means to combine said through traffic wavelengths and said plurality of added wavelengths, whereby the need of extinguishing wavelengths in the system is removed.

A low-loss hub ring network system comprising:

• a. a plurality of dynamic OADMs, each said OADM having an ADD section and a DROP section, and
• b. means for bi-directional transmission of a wavelength dropped at one said DROP sections and an identical wavelength added at one of said ADD sections, whereby said bi-directional transmission occurs on at least one ring of the ring network.