Abstract: A wavelength-selective routing capability is provided in a single network element by configuring the network element using a combination of add/drop network elements to route individual optical channels of WDM signals among a plurality of optical transmission paths coupled to the network element. Any optical channel of any WDM signal received at the network element can be selectively added, dropped, or routed among the multiple optical transmission paths within and external to the node.

Abstract: A wavelength-selective routing capability is provided in a single network element by configuring the network element using a combination of add/drop network elements to route individual optical channels of WDM signals among a plurality of optical transmission paths coupled to the network element. Any optical channel of any WDM signal received at the network element can be selectively added, dropped, or routed among the multiple optical transmission paths within and external to the node.

Abstract: Circuitry for a node of an optical communication network has a mux and/or a demux. In one embodiment, the circuitry has a mux and a demux implemented on a single circuit board, where (1) the mux is configured to combine up to eight different incoming OC3/OC12-rate electrical signals into a single outgoing OC48-rate electrical signal for conversion into two copies of an outgoing OC48 optical signal and (2) the demux is configured to split a working incoming OC48-rate electrical signal (selected from two incoming OC48-rate electrical signals converted from two incoming OC48 optical signals) into up to eight different outgoing OC3/OC12-rate electrical signals. The node is configured to perform automatic signal provisioning, which may be (a) the addition of a new OC3/OC12 signal; (b) the deletion of an existing OC3/OC12 signal; (c) the rate-upgrading of an existing OC3 signal to an OC12 signal; or (d) the rate-downgrading of an existing OC12 signal to an OC3 signal.

Abstract: Optical signal power levels for selected optical channels processed within an add/drop node in a wavelength division multiplexed (WDM) system are adjusted as a function of variations in signal power in an incoming WDM signal caused by gain ripple. In particular, a “ripple fitting” method is described whereby the optical signal power of individual optical channels being added at the add/drop node are adjusted to levels that correspond to the ripple profile of other optical channels being routed through the add/drop node. In this manner, the gain ripple in the WDM signal being output from the add/drop node approximately corresponds to the gain ripple in the incoming WDM signal at the node.

Abstract: Optical signal power levels for selected optical channels processed within an add/drop node in a wavelength division multiplexed (WDM) system are adjusted as a function of variations in signal power in an incoming WDM signal caused by gain ripple. In particular, a “ripple fitting” method is described whereby the optical signal power of individual optical channels being added at the add/drop node are adjusted to levels that correspond to the ripple profile of other optical channels being routed through the add/drop node. In this manner, the gain ripple in the WDM signal being output from the add/drop node approximately corresponds to the gain ripple in the incoming WDM signal at the node.

Abstract: A WDM input signal received at an add/drop node is coupled onto both a “drop” transmission path and a “through” transmission path within the node. Optical channels to be dropped are then processed within the “drop” path, such as by optical demultiplexing. Because a copy of the same WDM input signal is routed on the “through” path, a dynamically configurable and programmable wavelength blocker selectively blocks the optical channels that are being dropped from the WDM input signal and passes through those optical channels not being dropped onto the “through” path. In an “add” path within the node, optical channels are selectively added, such as by using optical multiplexing. Those optical channels from the multiplexed optical signal that are not designated for “add” (e.g., “unused” channels) are selectively blocked within the “add” transmission path.