Abstract: Extender apparatus for an optical network includes first and second extender units having an network-facing port for connection to a backhaul fiber and a subscriber-facing port for connection to a feeder fiber. Each extender unit includes a gain assembly and is operable selectively either in an enabled state, in which the gain assembly amplifies a signal received at either port of the extender unit and couples it to the other port of the extender unit, or in a disabled state, in which the gain assembly blocks coupling of a signal from either port of the extender unit to the other port of the extender unit. A failover unit is operable when the first extender unit is in the enabled state and the second extender unit is in the disabled state to detect occurrence of at least one fault condition in the first extender unit. The failover unit is responsive to the fault condition in the first extender unit to switch the first extender unit to the disabled state and the second extender unit to the enabled state.

Abstract: In order to increase the capacity of a deployed passive optical network (PON) without replacing optical network terminators (ONTs), a PON is provided that is partitioned into multiple channels. The upstream and downstream channels in the PON are partitioned into M channels, with the number of channels on the upstream preferably equaling the number of channels on the downstream. In the downstream, the partitioning is accomplished by use of wavelength division multiplexing filters arranged in a way as to place groups of ONTs on M different wavelength bands, where all of the wavelength bands are within the downstream wavelength range of the existing PON. On the upstream, partitioning is accomplished using “injection locking” to narrow the possible wavelength range of each ONT transmitter to a portion of that possible in the existing PON.

Abstract: Extender apparatus for an optical network includes first and second extender units having an network-facing port for connection to a backhaul fiber and a subscriber-facing port for connection to a feeder fiber. Each extender unit includes a gain assembly and is operable selectively either in an enabled state, in which the gain assembly amplifies a signal received at either port of the extender unit and couples it to the other port of the extender unit, or in a disabled state, in which the gain assembly blocks coupling of a signal from either port of the extender unit to the other port of the extender unit. A failover unit is operable when the first extender unit is in the enabled state and the second extender unit is in the disabled state to detect occurrence of at least one fault condition in the first extender unit. The failover unit is responsive to the fault condition in the first extender unit to switch the first extender unit to the disabled state and the second extender unit to the enabled state.

Abstract: Elastic buffering takes place within a head end terminal (200). An elastic buffer (206) has the effect of shifting time at its output frame-of-reference backward by a fixed amount to compensate for unknown time differences between time at its input frame-of-reference and time at the frame-of-reference of a remote node (150). The amount of time that the elastic buffer (206) shifts data is determined by a time-stamping technique, where data packets are time stamped at the remote node (150) and the time stamp is analyzed at the head end terminal (200) to determine the time shift.

Abstract: An optical amplifier including an input port and an output port which are coupled together via a data signal line; an amplifier circuit; a gain control circuit coupled to the data signal line and operative for detecting the power level of a burst signal input into the optical amplifier at the input port; and a dummy laser generation circuit having an output coupled to the data signal line and an input coupled to the gain control circuit; where the gain control circuit is operative for controlling the power level output by the dummy laser generation circuit so as to maintain the power level of a signal input into the amplifier circuit at a substantially constant level.

Abstract: An optical amplifier including: an amplifier having an input port and an output port, which is disposed along a main signal line of the optical amplifier; a dummy laser generation circuit having an output coupled to the main signal line and operative for inputting a dummy signal into the amplifier; a first optical detector for detecting a power level of the dummy signal into the amplifier and outputting a first power level signal; a second optical detector for detecting an amplified power level of the dummy signal output by the amplifier and outputting a second power level signal; a memory device for storing calibration data regarding the gain characteristics of the amplifier; and a gain control circuit which receives inputs from the first optical detector and second optical detector, and has an output coupled to the amplifier. The gain control circuit operates to control the gain of the amplifier based on the first power level signal, the second power level signal and the calibration data.

Abstract: Elastic buffering takes place within a head end terminal (200). An elastic buffer (206) has the effect of shifting time at its output frame-of-reference backward by a fixed amount to compensate for unknown time differences between time at its input frame-of-reference and time at the frame-of-reference of a remote node (150). The amount of time that the elastic buffer (206) shifts data is determined by a time-stamping technique, where data packets are time stamped at the remote node (150) and the time stamp is analyzed at the head end terminal (200) to determine the time shift.

Abstract: A radio communications system (10) having a mobile station (30) and at least two base stations (13, 14). ATM radio channels (31, 32) are provided between the remote station and the base stations. Each of the ATM channels supports communication though ATM cells over a common frequency band. When handoff conditions are met for a handoff from the first base station to the second base station, a second virtual path identifier and a second virtual connection identifier are selected for a connection between the second base station and the remote station.

Abstract: A radio communications system (10) having a mobile station (30) and at least two base stations (13, 14). ATM radio channels (31, 32) are provided between the remote station and base stations. Each of the ATM channels supports communication though ATM cells over a common frequency band. At least one ATM node (21) is coupled to the base stations. A base station controller (11) is coupled to the ATM node. The base station controller has a combiner (303) for combining cell streams received from the first and second base stations and an ATM signalling circuit (330) for sending ATM commands to the ATM node for dividing cell streams at the ATM node to the first and second base stations. The remote station (30) has a logic unit (520) for combining cell streams received from the first and second base stations during a handoff from the first base station to the second base station.

Abstract: A radio communications system (10) having a remote or mobile station (30) and at least two base stations (13, 14). ATM radio channels (31, 32) are provided between the remote station and base stations. The remote station (30) has a logic unit (520) for combining cell streams received from the first and second base stations during a handoff from the first base station to the second base station. A receiver in the remote station (30) is powered up during first time periods corresponding to physical layer synchronization cells arriving from one base station (13) and second time periods corresponding to ATM cells arriving from the other base station. When handoff conditions are met, the receiver is powered up for a third time period longer than the first and second time periods.

Abstract: A radio communications system (10) having a mobile station (30) and at least two base stations (13, 14). ATM radio channels (31, 32) are provided between the remote station and base stations. Each of the ATM channels supports communication though ATM cells over a common frequency band. At least one ATM node (21) is coupled to the base stations. A base station controller (11) is coupled to the ATM node. The base station controller has a combiner (303) for combining cell streams received from the first and second base stations and an ATM signalling circuit (330) for sending ATM commands to the ATM node for dividing cell streams at the ATM node to the first and second base stations. The remote station (30) has a logic unit (520) for combining cell streams received from the first and second base stations during a handoff from the first base station to the second base station.

Abstract: A switching node for an ATM network can selectably implement one of a plurality of call transforming procedures. The switching node stores characteristics of each connected communications link in a virtual connection and determines, for any ATM message the quality of service requirements for a particular transfer over a virtual connection. The selection of a call transferring process is based upon minimizing a particular potential error. Decisions concerning the implementation of correction procedures and the capability of the virtual connection to accommodate these requirements are made on a link-by-link basis.

Abstract: A combination of an end-to-end closed-loop rate control mechanism for controlling the flow of cells entering a cell relay communication network from an end system, along with a segment traffic control mechanism for protecting the segment against misbehaving or malfunctioning destination end systems provides a novel, more efficient traffic management system and method for cell flow regulation in a cell relay communication network.

Abstract: An adaptive congestion control device (600) and method minimize congestion using independent congestion level indicators. The invention allows efficient recovery for an integrated packet network that becomes congested and allows a user to utilize the network on a space-available basis when capacity is available.