Communications network for a metropolitan area

A method of operating a metropolitan photonic network comprising the steps of:

• providing to an access multiplexer a dense wavelength division multiplex (DWDM) quality unmodulated wavelength from a source remote therefrom;
• modulating the wavelength with packet data at the access multiplexer;
• multiplexing the wavelength together with other modulated wavelengths to form a sparse wavelength division multiplexed (S-DWDM) signal, the S-DWDM signal having an optical precision capable of being interleaved into the optical frequency constraints of a dense wavelength division multiplex (DWDM) wavelength plan used in a core network;
• transporting the S-DWDM signal to a metro photonic switch, the metro photonic switch being all-optical;
• demultiplexing the S-DWDM signal to a plurality of wavelengths;
• switching each of the plurality of wavelengths on a per wavelength basis;
• multiplexing different switched wavelengths to form a (DWDM) signal;
• and
• launching the DWDM signal toward a core node in the core network.

A photonic metropolitan network comprising:

• means for providing to the access multiplexer a dense wavelength division multiplex (DWDM) quality unmodulated wavelength from a source remote therefrom;
• an access multiplexer including means for modulating the wavelength with packet data at the access multiplexer, and means for multiplexing the wavelength together with other modulated wavelengths to form a sparse wavelength division multiplexed (S-DWDM) signal, the S-DWDM signal having an optical precision capable of being interleaved into the optical frequency constraints of a dense wavelength division multiplex (DWDM) wavelength plan used in a core network;
• means for transporting the S-DWDM signal to the metro photonic switch;
• wherein the metro photonic switch is all-optical, includes means for demultiplexing the S-DWDM signal at the metro photonic switch to a plurality of wavelengths;
• means for switching each of the plurality of wavelengths on a per wavelength basis;
• means for multiplexing different switched wavelengths to form a DWDM signal;
• and means for transporting the DWDM signal to a core node in the core network.

A communications network for a metropolitan area comprising:

• a plurality of access multiplexers, each access multiplexer operable to provide multiplexing of data packets from a plurality of end-users onto a sparse dense wavelength division multiplexed (S-DWDM) wavelength, the S-DWDM wavelength having an optical precision capable of being interleaved into the optical frequency constraints of a first separation being multiple of a second separation in a dense wavelength division multiplex (DWDM) wavelength plan used in a core network;
• a photonic switch, coupled to the access multiplexers via fiber optic cable for carrying a plurality of the S-DWDM wavelengths, being all-optical and operable to switch the plurality of S-DWDM wavelengths into a DWDM signal for transmission;
• a core node, coupled to the photonic switch via a fiber optic cable for carrying the DWDM signal, and operable to mute the data packets within the communications network or out to a long haul network;
• and
• a control plane coupled to the photonic switch and the core node for effecting end-to-end photonic connectivity.