1694 results about "Passive optical network" patented technology

The present invention discloses a low-cost light source for optical transmission systems and optical networks based on wavelength-division multiplexing (WDM) technology. A light source in accordance with the present invention is implemented by externally injecting a narrow-band incoherent light into a Fabry-Perot laser diode (F-P LD). After injection of narrow-band incoherent light, the output of F-P LD becomes wavelength-selective rather than multi-mode and the output wavelength of F-P LD coincide with the peak wavelength of the injected incoherent light. Multi-channel WDM light sources according to the present invention can be implemented using a single broadband incoherent light source and plurality of F-P LDs. An optical transmission system for upstream signal transmission in an passive optical network using the light source according the present invention is also disclosed.

A wavelength division multiplexed optical access network including a central office for multiplexing first optical signals used for transmitting a high-speed wire data service to a subscriber side and second optical signals used for transmitting a wireless data service to a remote subscriber terminal, a remote node connected to the central office through an optical fiber and for de-multiplexing a multiplexed optical signal received from the central office, a plurality of subscribers connected to the remote node, each subscriber receiving a first optical signal having a corresponding wavelength from among the de-multiplexed first optical signals, and a plurality of radio access units connected to the remote node, each radio access unit converting a second optical signal having a corresponding wavelength from among the de-multiplexed second optical signals into a wireless electric signal and wirelessly transmitting the wireless electric signal.

System, apparatus and method for connecting a passive optical network (“PON”) to a power line communications (“PLC”) network using a PLC HeadEnd installed at the PON to provide for distribution of high speed, broadband data communications services available on the PON to the PLC network using high speed, broadband PLC data signals. Where the PLC HeadEnd is installed on a medium voltage power distribution network, a PLC bypass unit is installed at a medium voltage/low voltage power transformer in the PLC network to provide PLC signal connectivity between the MV and LV networks. A PLC residential gateway is installed at each end user facility, such as a home or business, desiring broadband service available on the PON.

An in-band OTDR uses a network's communication protocols to perform OTDR testing on a link. Because the OTDR signal (probe pulse) is handled like a data signal, the time required for OTDR testing is typically about the same as the time required for other global network events, and is not considered an interruption of service to users. A network equipment includes an optical time domain reflectometry (OTDR) transmitter and receiver, each operationally connected to a link to transmit and receive, respectively, an OTDR signal. When an OTDR is to be performed, a network device operationally connected to the link actuates the OTDR transmitter to transmit the OTDR signal on the link during a determined test time based on a communications protocol of the link, during which data signals are not transmitted to the network equipment. A processing system processes the OTDR signal to provide OTDR test results.

In a PON system with WDM, at the time of initial setting, each ONU negotiates with an OLT, and automatically acquires a wavelength which can be used by the ONU. One wavelength for negotiation of assigned wavelength is fixed as a default, and a newly connected ONU first uses the wavelength. The OLT 200 includes a plurality of light sources for downstream communication. The ONU 300 includes a wavelength variable filter selectively receiving one of wavelengths of downstream communication, and a wavelength variable light source selectively emitting light of one of plural wavelengths for upstream communication. The ONU 300 uses a transmission wavelength (for example, λu32) for negotiation and transmits a wavelength assignment request 1000 to the OLT 200. The OLT 200 selects a wavelength λu1 to be assigned from unused wavelengths, and transmits wavelength information to the ONU 300. The OLT 200 and the ONU 300 communicates using the notified wavelengths.

An enhanced passive optical network (PON) processor adapted to serve a plurality of PON applications is disclosed. The PON processor is a highly integrated communications processor that can operate in different PON modes including, but not limited to, a gigabit PON (GPON), a broadband PON (BPON), an Ethernet PON (EPON), or any combination thereof. In an embodiment of the present invention the provided PON is fabricated on a single integrated circuit (IC).

A key management device and method which is required for provision of a security service in an EPON vulnerable to security breaches due to characteristics of Ethernet. A session key distribution function is performed in such a manner that, during the process of communication setup between an OLT and an ONU, the OLT multicasts a public key and the ONU receives the public key from the OLT and then distributes a corresponding session key to the OLT. A session key update function is performed in such a manner that an existing session key is updated with a new one through a periodic MPCP general gate message and an ONU report message.

A method includes provisioning joint bandwidth in a software defined passive optical network PON based mobile backhaul MBH and cache management on base stations for video delivery across the network, the provisioning in each time unit includes grouping bandwidth utilization in the network into a first category used to support video requests which cannot directly be served by caches on base stations, the first category video requests being high priority, and if bandwidth remains after the high priority requests remaining bandwidth being used to deliver some videos that are low priority to caches.

A solution for detecting and recovering from a failure in a protected single-fiber passive optical network. A detector is used to detect the degradation in power level of optical signals. Furthermore, the invention discloses a variable symmetric split ratio approach to improve the number of splits (e.g. the number of ONUs). A single-fiber passive optical network is disclosed that uses a plurality of passive nodes connected in the optical fiber between the interfaces, wherein in the passive nodes 2-by-2 splitters/combiners are used to couple optical power from and into the optical fiber at a predetermined split ratio.

One embodiment of the present invention provides a system that facilitates dynamic allocation of upstream bandwidth in a passive optical network which includes a central node and at least one remote node. Each remote node is coupled to at least one logical entity, which corresponds to a device or a user, that transmits upstream data to the central node and receives downstream data from the central node. The central node is coupled to an external network outside of the passive optical network through a shared out-going uplink.

The present invention is an apparatus, method and system for time synchronizing data from various sensor types that enables data fusion and transport. To provide this capability, the present invention utilizes an inverted Passive Optical Network (PON) approach for synchronous communication. Further, the present invention introduces an inverted Passive Electrical Network (iPEN) that extends the iPON approach. Data that are in a common format with embedded time synchronization information can easily be integrated or fused and transported over such communication links. The present invention provides the ability to merge and aggregate data from a wide range of disparate sensors and systems while maintaining close synchronization. The present invention is appropriate for synchronization of data, voice, and video onto a single network and/or multi-tiered networks and can also handle signal processing and control technologies at line rates well into the Gigabits per second (Gbps) range.

A system and method are disclosed in which an optical network may include an optical-electrical converter module within an OEO (Optical Electrical Optical) reach extension system (OEO RE system), the OEO RE system having an OEO port and including a downstream frame regeneration block; and a downstream control data extraction block including a GPON operating parameter extraction module (GOPEM), wherein the GOPEM is operable to extract at least one OEO-port operating parameter from data frames arriving at the GOPEM module.

A system (100) to enable the transfer of Internet protocol (IP) format data (12, 14) over a point-to-multipoint passive optical network (PON, 16) is illustrated in FIG. 2. An exchange (102) is connected to a plurality of outstations (104-108) via an optical communication resource (24, 26-38) including a passive optical splitter (22) providing isolation to individual outstations. Media access control of the plurality of outstations is administered by the exchange (102), with collision detection logic (112) in the exchange determining collision (158) of Internet protocol (IP) encoded data communicated thereto through the PON (16). The IP encoded data realises a transport mechanism through the PON. Each of the plurality of outstations (104-108) and the exchange (102) is adapted to pass data in an IP format to and from the optical communication resource such that IP encoded data is transported, in use, directly between the outstation and the exchange.

The invention relates to optical communication field, discloses a collating device and method for dynamic bandwidth in source-free optical network, and the distribution method for dynamic bandwidth is transparent, which can satisfy the requirement for different service, improve the utilization rate of bandwidth, realize the fair distribution for bandwidth, good haleness, real time, and can distribute bandwidth for different port, and support to release offline bandwidth of ONU. The distributing device for dynamic bandwidth in source-free optical network includes ascending service active fiber network unit bit-mapping register, ascending service active port bit-mapping table, ascending virtual media accessing control sub-layer information table, descending virtual media accessing control sub-layer authorization information table; said distributing device for dynamic bandwidth, consults said fiber network unit active information, port active information and length information of sending data, according to preset priority of different service, process the service flow according to priority according to preset priority, and distributes the dynamic bandwidth for ports.

A hub for use in a passive optical network (PON) includes a transmission fiber on which an information-bearing optical signal is received, a double-cladded, rare-earth doped fiber located along the transmission fiber for imparting gain to the information-bearing optical signal, and a combiner having an output coupled to the transmission fiber and a plurality of inputs. The output is coupled to the transmission fiber such that optical energy at pump energy wavelengths but not signal wavelengths are communicated therebetween. At least one pump source is optically coupled to one of the inputs of the combiner for providing optical pump energy to the double-cladded, rare-earth doped fiber. An optical splitter is also provided. The optical splitter has an input coupled to the transmission fiber for receiving an amplified, information-bearing optical signal and a plurality of outputs for directing portions of the amplified, information-bearing optical signal to remote nodes in the PON.