Abstract:
Routing of optical paths through an optical network may account for both linear and non-linear effects of the physical layer when determining the route. The non-linear effects may be determined only as necessary, allowing the non-linear effects to be included in the routing determination for larger optical networks.
Abstract:
TDR (101) locates impairments in a network carrying burst signals (405) during burst intervals (401). TDR (101) comprises a transmitter (502), receiver (505-08), level detector (511), controller (504), accumulator (510), and probe detector (512). Transmitter (502) transmits probe signals (123/302) to impairment, causing reflection of probe signals (124). Receiver (505-08) receives reflected signals (124) during receiving intervals (404), and receives burst signals (405) during intervals that overlap burst intervals. Level detector (511) measures level of received signals. Controller (504) determines which interval is free of burst signals, based on level measurement. Accumulator (510) accumulates reflected probe signals free of burst signals. Probe detector (512) detects impairment from accumulated signals and estimates time delay. Distance to impairment is estimated from time delay.
Abstract:
A radio over fibre system (5) comprises a base station (10, 20) with a first base station node (10) and a second base station node (20) connected by an optical communication link (30). At least one of the base station nodes (10, 20) comprises an optical transmitter (17, 23). A method of determining an operating parameter for the optical transmitter (17, 23) comprises receiving signal quality parameters for a plurality of user equipments (UE) served by the base station (10, 20). The method determines an operating parameter of the optical transmitter using the determined signal quality parameters of the plurality of user equipments (UE). The operating parameter of the optical transmitter can be a modulation parameter.
Abstract:
Aspects of the present disclosure aim at configuring an optical time domain reflectometry (OTDR) in a central office such that the OTDR is configured to be operatively coupled with and also configured to periodically poll each fiber at defined intervals and compute/store a reflection signature that can be used to compare with future signatures received from subsequent polls of the fiber to determine a fault (e.g., a fiber cut or breakage) between the central office (CO) and one or more optical network unit (ONU) over GIS.
Abstract:
A method, apparatus, and system for network monitoring, and more specifically for correlating downstream devices in an optical network with downstream ports of an optical splitter through which they are communicating with a central office. The downstream devices operational on the network are identified and listed in a correlation table. Selected subsets of these devices are then monitored, preferably by an ISM under the direction of a management node, in a series of monitoring cycles until a satisfactory correlation may be achieved. The correlation cycle may be performed at startup, as needed, or on a periodic basis.
Abstract:
The present invention describes systems (1, 12) and methods for control of optical devices and communications subsystems. The control system comprises ASIC sub-modules and programmable circuitry (25) which may be integrated into a self-contained, stand-alone module. In one embodiment, the module has one or more FPGAs (25) in conjunction with RF and Digital ASICs (30), an integrated cross-connect (36) between the FPGA and digital and RF ASIC" building blocks, and an integrated cross-connect (41) between the ASIC and optical circuits and supporting functions. Programmable chip control and other transmission and tuning functions, programmable transponders, and each FPGA/ASIC (25, 30) that is incorporated into a transponder form factor or a host board, can have the same or different functionalities and other parameters including but not limited to modulation format.
Abstract:
The present invention includes novel techniques, apparatus, and systems for optical WDM communications. Tunable lasers are employed to generate respective subcarrier frequencies which represent subchannels of an ITU channel to which client signals can be mapped. In one embodiment, subchannels are polarization interleaved to reduce crosstalk. In another embodiment, polarization multiplexing is used to increase the spectral density. Client circuits can be divided and combined with one another before being mapped, independent of one another, to individual subchannels within and across ITU channels. A crosspoint switch can be used to control the client to subchannel mapping, thereby enabling subchannel protection switching and hitless wavelength switching. Network architectures and subchannel transponders, muxponders and crossponders are disclosed, and techniques are employed (at the subchannel level/layer), to facilitate the desired optical routing, switching, concatenation and protection of the client circuits mapped to these subchannels across the nodes of WDM network.