Abstract: An apparatus for determining a position of a disturbance to an optical fibre assembly comprises two monitoring units each comprising a respective light detector and a respective clock. The first monitoring unit receives a first digital optical signal from the optical fibre assembly. The second monitoring unit receives a second digital optical signal from the optical fibre assembly. The apparatus monitors the state of polarisation of the first and second digital optical signals and determines respective times at which a change occurs in the state of polarisation of each signal, the change arising from a disturbance to the optical fibre assembly. The apparatus uses said times to determine a position of the disturbance.

Abstract: An apparatus for use in a packet-based communication system, comprises an input and an output. The apparatus is configured to receive a stream of data packets, having an inter-packet spacing, and store the received data packets and information representing the inter-packet spacing in a buffer, wherein the data packets are no longer than a common maximum data-packet length. The apparatus is further configured to schedule, at intervals, all the contents of the buffer except for a constant amount, into a respective container of a sequence of containers and, if the container then contains an incomplete data packet, schedule the remainder of the incomplete packet into the container. The apparatus is further configured to send the sequence of containers, wherein the positions of the data packets within the containers depend on the received inter-packet spacing, and wherein the constant amount is equal to or greater than the common maximum data-packet length.

Abstract: An apparatus for use in a packet-based communication system, comprises an input and an output. The apparatus is configured to receive a stream of data packets, having an inter-packet spacing, and store the received data packets and information representing the inter-packet spacing in a buffer, wherein the data packets are no longer than a common maximum data-packet length. The apparatus is further configured to schedule, at intervals, all the contents of the buffer except for a constant amount, into a respective container of a sequence of containers and, if the container then contains an incomplete data packet, schedule the remainder of the incomplete packet into the container. The apparatus is further configured to send the sequence of containers, wherein the positions of the data packets within the containers depend on the received inter-packet spacing, and wherein the constant amount is equal to or greater than the common maximum data-packet length.

Abstract: A network-based communication system has a source network apparatus and a destination network apparatus. The source apparatus receives a stream of information-bearing packets, the stream comprising gaps between at least some of the information-bearing packets. It generates one or more spacer packets, and generates an augmented stream of packets which comprises the information-bearing packets and further comprises spacer packets located within at least some of said gaps, wherein the spacing of the information-bearing packets in the augmented stream is the same as the spacing of the corresponding information-bearing packets in the received stream. It outputs the augmented stream of packets to a network link. The destination apparatus receives the augmented stream of packets and determines whether each received packet is an information-bearing packet or a spacer packet. It outputs or processes the received information-bearing packets, or information from these packets, but discards the received spacer packets.

Abstract: A network node comprises an optical input, an optical output, a random-access queue and processing system. It receives a data packet, at the optical input and determines whether to process it as a guaranteed-service packet or as a statistically-multiplexed packet. A guaranteed-service packet is output within a predetermined maximum time of receipt, optionally within a data container comprising container control information. A statistically-multiplexed packet is queued. The node determines a set of statistically-multiplexed packets that would fit a gap between two guaranteed-service packets; selects one of the packets; and outputs it between the two guaranteed-service packets.

Abstract: A network node comprises an optical input, an optical output, a random-access queue and processing system. It receives a data packet, at the optical input and determines whether to process it as a guaranteed-service packet or as a statistically-multiplexed packet. A guaranteed-service packet is output within a predetermined maximum time of receipt, optionally within a data container comprising container control information. A statistically-multiplexed packet is queued. The node determines a set of statistically-multiplexed packets that would fit a gap between two guaranteed-service packets; selects one of the packets; and outputs it between the two guaranteed-service packets.

Abstract: A network node comprises an optical input, an optical output, a random-access queue and a processing system. It receives a data packet, at the optical input and determines whether to process it as a guaranteed-service packet or as a statistically-multiplexed packet. A guaranteed-service packet is output within a predetermined maximum time of receipt, optionally within a data container comprising container control information. A statistically-multiplexed packet is queued. The node determines a set of statistically-multiplexed packets that would fit a gap between two guaranteed-service packets; selects one of the packets; and outputs it between the two guaranteed-service packets.

Abstract: The present invention discloses a system for signalling within optical or combined optical/electronic networks wherein a first transmission node executes polarization multiplexing on transmitted traffic, and at one or more intermediate nodes one or more of the following processes are carried out on the sent traffic: demultiplexing by polarization and/or polarization and/or SOP-alignment. Further a method for packet handling within optical packet switched networks where, at a first transmission node carries out polarization demultiplexing of transmitted traffic, and at one or a number of intermediate nodes carries out one or more of the following processes on the transmitted traffic; demultiplexing by polarization, and/or polarization and/or SOP-alignment. Said separation into states of polarization is used in separation of QoS-classes.

Abstract: A network node comprises an optical input, an optical output, a random-access queue and a processing system. It receives a data packet, at the optical input and determines whether to process it as a guaranteed-service packet or as a statistically-multiplexed packet. A guaranteed-service packet is output within a predetermined maximum time of receipt, optionally within a data container comprising container control information. A statistically-multiplexed packet is queued. The node determines a set of statistically-multiplexed packets that would fit a gap between two guaranteed-service packets; selects one of the packets; and outputs it between the two guaranteed-service packets.

Abstract: In asynchronous optical packet switches, scheduling packets from a buffer randomly will cause less efficient utilization of the buffer. Additionally, reordering of packets may cause problems for service quality demanding applications. According to the present invention a new electronic buffer scheduling algorithm is proposed and a switch utilizing this algorithm is disclosed. The algorithm is designed for utilizing the buffer resources efficiently, still avoiding serious packet reordering.

Abstract: The present invention discloses a system for signalling within optical or combined optical/electronic networks wherein a first transmission node executes polarization multiplexing on transmitted traffic, and at one or more intermediate nodes one or more of the following processes are carried out on the sent traffic: demultiplexing by polarization and/or polarization and/or SOP-alignment. Further a method for packet handling within optical packet switched networks where, at a first transmission node carries out polarisation demultiplexing of transmitted traffic, and at one or a number of intermediate nodes carries out one or more of the following processes on the transmitted traffic; demultiplexing by polarisation, and/or polarisation and/or SOP-alignment. Said separation into states of polarisation is used in separation of QoS-classes.

Abstract: The present invention discloses a system for signalling within optical or combined optical/electronic networks wherein a first transmission node executes polarization multiplexing on transmitted traffic, and at one or more intermediate nodes one or more of the following processes are carried out on the sent traffic: demultiplexing by polarization and/or polarization and/or SOP-alignment. Further a method for packet handling within optical packet switched networks where, at a first transmission node carries out polarization demultiplexing of transmitted traffic, and at one or a number of intermediate nodes carries out one or more of the following processes on the transmitted traffic; demultiplexing by polarization, and/or polarization and/or SOP-alignment. Said separation into states of polarization is used in separation of QoS-classes.

Abstract: In asynchronous optical packet switches, scheduling packets from a buffer randomly will cause less efficient utilization of the buffer. Additionally, reordering of packets may cause problems for service quality demanding applications. According to the present invention a new electronic buffer scheduling algorithm is proposed and a switch utilizing this algorithm is disclosed. The algorithm is designed for utilizing the buffer resources efficiently, still avoiding serious packet reordering.

Abstract: The present invention discloses a system for signalling within optical or combined optical/electronic networks wherein a first transmission node executes polarization multiplexing on transmitted traffic, and at one or more intermediate nodes one or more of the following processes are carried out on the sent traffic: demultiplexing by polarization and/or polarization and/or SOP-alignment. Further a method for packet handling within optical packet switched networks where, at a first transmission node carries out polarisation demultiplexing of transmitted traffic, and at one or a number of intermediate nodes carries out one or more of the following processes on the transmitted traffic; demultiplexing by polarisation, and/or polarisation and/or SOP-alignment. Said separation into states of polarisation is used in separation of QoS-classes.

Abstract: A clothes hanger of the folding type. The carrying arm of the clothes hangers are articulated with each other, and at the joint connection have disc-like parts which are equipped with respective blocking notches which engage with a spring-actuated locking member mounted in the carrying piece of the clothes-hanger, the disc-like parts together forming a casing for taking up the spring.