Abstract:
A system or a network may include an optoelectronic module that includes an optical transmitter optically coupled with an optical fiber, and a controller communicatively coupled to the optical transmitter. The controller may be configured to operate the optical transmitter to transmit data signals through the optical fiber. The optoelectronic module may be configured to transmit time synchronization signals through the optical fiber along with the data signals.
Abstract:
An optical add-drop multiplexer (140) including a first filter (142, 420) filtering a first band (B E , C) of wavelengths (λ Ε , λ C ) of a communication spectrum for a first communication segment (105a) and a second filter (142, 430) filtering a second band (B A , L) of wavelengths (λ Α , λ L ) of the communication spectrum for a second communication segment (105b). The second band of wavelengths overlaps the first band of wavelengths in an overlap band (B O ) of wavelengths (λ O ). The overlap band may have a variable size. The first band of wavelengths includes a first fraction of the overlap band of wavelengths for the first communication segment and the second band of wavelengths includes a remaining fraction the overlap band of wavelengths for the second communication segment.
Abstract:
Optical network apparatus comprises an optical add drop multiplexer (10) comprising an optical signal input (11) and an optical signal output (12). An add input path (15) is connected to the optical signal output (12) for receiving a wavelength channel to be added. A drop output path (16) is connected to the optical signal input (11) for outputting a wavelength channel to be dropped. A through signal path (18) is connected between the optical signal input (11) and the optical signal output (12). An optical filter (20) is positioned in the add input path (15) for filtering an optical signal received on the add input path (15) from an optical terminal (40). A reflective device (30) in the add input path (15) is arranged to form an optical seed signal by returning at least a portion of the filtered optical signal. The optical seed signal is for use in seeding an optical transmitter at the optical terminal (40). The reflective device (30) is positioned between the optical filter (20) and the optical signal output (12). The drop output path (16) and the through signal path (18) bypass the reflective device (30).
Abstract:
A passive optical network has an optical line terminal (10), passive add drop wavelength multiplexers (20), at different locations along a first optical path, and an optical network termination part (30) coupled to the optical add path and optical drop path of a respective one of the passive add drop multiplexers. The passive add drop wavelength multiplexers are stand-alone parts separate from their respective optical network termination parts, being optically passive, unpowered and having a static configuration of wavelengths. By using such passive ADMs spread along the first optical path acting as a feeder, the PON is no longer limited to a tree structure. Also, the expense of an AWG device can be avoided. By making the ADMs stand-alone passive devices they can be located anywhere, and are non-specific to the types of terminal equipment, so later upgrade or standardisation of the terminal equipment is easier.
Abstract:
A system and method for monitoring an optical communication system. The system may include trunk terminals coupled through a trunk path and a branch terminal coupled the trunk path. A monitoring signal routing device within the branch terminal routes a monitoring signal from a branch-drop path to a branch-add path.
Abstract:
An optical access network (5) comprises L wavelength division multiplexed access sub-networks (10,11,12), where L>2. Each of the wavelength division multiplexed access sub-networks (10,11,12) is arranged to use a set of wavelength channels (λ 1 -λ N ). M optical line termination apparatus (41,42,43), where M>1, each receive traffic from a respective operator network (51,52,53) and output traffic on the wavelength channels. A wavelength routing apparatus (110) comprises M sets of first ports (35) and L second ports (24). Each set of first ports connects to a respective one of the optical line termination apparatus (41,42,43) and each second port connects to an optical link (16) of a respective one of the wavelength division multiplexed access sub- networks. The wavelength routing apparatus (110) is arranged to route the wavelength channels (λ 1 -λ N ) between the sets of first ports (35) and the second ports (24) and to route different wavelength channels of the same wavelength to different ones of the second ports (24).
Abstract:
For a WDM ring network, a node has an optical add drop part (60, 62, 64) and a transponder having a wavelength tunable transmitter (20) for sending a selectable one of the wavelengths in a selectable direction around the ring to a destination node. There is a controller (30) configured to select the wavelength to be sent by the wavelength tunable transmitter and to change the direction of sending around the ring, in response to a detection of a fault in sending in one of the directions. By making the transponder colourless and yet able to select direction, a simple protection switching capability can be added to an existing low cost WDM ring network having passive optical filters. This can be achieved without the need for a reconfigurable optical add drop multiplexer and associated control plane.