Method for auto-configuration of a wavelength selective switch in an optical network
View Patent ↗The invention relates to a method for auto-configuring a wavelength selective switch (WSS) device having an output port and a plurality of input ports and coupled to a WSS controller. When connected to a WDM optical network, the WSS controller is programmed to utilize one or more optical channel monitors (OCM) coupled to the input and/or output ports to detect which of the wavelengths are present at the input ports. Wavelengths that are not detected on any input port are blocked by the WSS. Any wavelength detected as present at one and only one input port is switched by the WSS to the output port. If a wavelength is detected at two or more input ports, it is either blocked by the WSS at each of the input ports until user intervention, or is blocked at all but one of the input ports as defined by assigned port priorities.
1. A wavelength selective switch (WSS) device comprising:
a WSS element having a control port, an output port and a plurality of input ports for selectively switching any of a plurality of supported wavelength from any of the input ports to the output port or for blocking thereof,
a WSS controller coupled to the control port of the WSS element for controlling the switching, and
one or more optical channel monitors (OCM) coupled to the input and/or output ports of the WSS element and to the WSS controller,
wherein the WSS controller is configured to auto-configure the WSS element when the WSS device is connected to an optical WDM network, by:
co-operating with the one or more OCM to detect the presence of the supported wavelengths at each of the input ports; and,
sending control signals to the control port of the WSS element for controlling the WSS element in such a way that
i) optical connections between each of the input ports and the output port within the WSS element at any of the supported wavelengths that is not detected by the one or more OCM at any of the input ports are blocked by the WSS element, by ensuring that optical loss between each of the input ports and the output port exceeds a pre-determined value at said wavelengths;
ii) any supported wavelength whose presence is detected by the one or more OCM at one and only one of the input ports is switched to the output port; and,
iii) any supported wavelength whose presence is detected at more than one of the input ports is either blocked at each of the input ports until user intervention, or is blocked at all but one of the input ports and is directed to the output port from a single one of the input ports receiving said wavelengths which has a comparatively higher priority assigned thereto.
2. The WSS device of claim 1 wherein the pre-determined value of the optical loss is at least 20 dB.
3. The WSS device of claim 1 , wherein the WSS controller is configured to:
a) receive information from the one or more OCM which of the supported wavelengths are present at at least one of the input optical ports;
b) based on the information received from the one or more OCM, determine which of the received wavelengths are present at one and only one of the input optical ports; and,
c) at each of the wavelengths identified in step (b), provision an optical connection in the WSS element between a corresponding input optical port and the output optical port.
4. The WSS device of claim 3 , wherein the WSS controller is further configured to
identify, based on the information received from the one or more OCM, a wavelength conflict wherein one of the supported wavelengths is detected at two or more of the input ports.
5. The WSS device of claim 4 , wherein the WSS controller is further configured to
at least temporarily block optical connections between each of the input ports and the output port at the one of the supported wavelengths for which the wavelength conflict is identified.
6. The WSS device of claim 4 , wherein the WSS controller is further configured to
generate a wavelength conflict alarm when the presence of the one of the supported wavelengths at the two or more of the input ports is detected by the one or more OCM.
7. The WSS device of claim 4 wherein the two or more of the input ports are assigned different priorities,
wherein the WSS controller is further configured to provision an optical connection in the WSS element, at the one of the supported wavelengths for which the wavelength conflict was identified, between the output port and a selected one of the two or more input ports receiving said wavelength that is selected according to the assigned priorities.