Patent ID: 7499647
Filing Date: 2009-03-03
Classification: H04B,H04J,H04L

Abstract:
1. An all optical network for optical signal traffic, comprising: a first ring with at least a first clockwise fiber, a second counter-clockwise fiber and a plurality of network nodes; each node including at least a WDM transponder that includes a line-side transmitter and a client-side receiver in a first direction, and a line-side receiver and a client-side transmitter in an opposing second direction; the line-side receiver including a fixed or a tunable optical wavelength filter; at least a first add and a first drop broadband or narrowband couplers positioned on each fiber, each coupler having first and second ports for through traffic and a third port for adding or dropping local traffic, the first add and first drop broadband couplers being configured to minimize a pass-through loss in each fiber; a first coupler pair including first and second couplers in each network node, the first coupler having first and second output ports and a first input port coupled to a line-side transmitter, the first output port being coupled to the clockwise fiber and the second output port being coupled to the counter-clockwise fiber; the first coupler enabling the line-side transmitter to launch signals to both the clockwise and counter-clockwise fibers; the second coupler having first and second input ports and a first output port coupled to a line-side receiver, the first input port being coupled to the clockwise fiber and the second input port coupled to the counter-clockwise fiber; the second coupler enabling the line-side receiver to receive signals from both the clockwise and counter-clockwise fibers; and a single hub switch coupled in the first clockwise and second counter-clockwise fibers as a central protection switch to open an optical break point in each of the first clockwise and second counter-clockwise fibers when there is no other break point in the first clockwise and second counter-clockwise fibers and to close the optical break point when there is a break point in at least one of the first clockwise and second counter-clockwise fibers.