Abstract: A data center network node (28) comprises one or more switch (18,19,22,23) configured to link an optical transceiver (16,17) to an optical connection comprising a multi-core optical fiber (30) having a plurality of cores (31). For each core (31), the one or more switch (18,19,22,23) is configurable between a first configuration in which an optical signal on a said core (31) of the multi-core optical fiber bypasses the optical transceiver and a second configuration in which the optical transceiver is optically linked to the said core (31) of the multi-core optical fiber (30).

Abstract: A data center network node comprising at least one server connection for connecting to a server 6, a connection 7 for connecting the at least one server 6 to a first subnetwork. The first subnetwork is a conventional subnetwork which comprises at least one of a switch or a router. The node further comprises an optical receiver array 20 for connecting the node to an optical offload subnetwork, wherein the optical receiver array 20 comprises a plurality of optical receivers. The array is configured such that each receiver is connectable to an optical path within a multi-path optical connection. The node further comprises an optical transmitter array 23 for connecting the node to an optical offload subnetwork. The optical transmitter array comprises a plurality of optical transmitters. The array is configured such that each receiver is connectable to an optical path within a multi-path optical connection.

Abstract: A method of providing state synchronization between a controller and a switch in a communications network, wherein the controller provides flow data for routing flows through the switch and transmits, in flow modification messages, the flow data to the switch for storage in flow tables, the state synchronization comprising ensuring that flow data in the flow tables of the switch are consistent with the flow data provided by the controller. The method comprises, by the controller (19), providing (21) an identifier in each flow modification message.

Abstract: A method for managing traffic of a plurality of packets in a plurality of packet flows transmitted using a time-slotted interface. The packet flows traverse a plurality of switches of a transport network according to an assigned path from a source node to a destination node. The method comprises determining an end-to-end latency of a plurality of packets traversing a current switch in packet flows and assigning priority values to the packets traversing the current switch, wherein a priority value of a packet depends on the determined end-to-end latency of said packets. The method further comprises allocating a time slot in an output interface of the current switch to the packet having the highest priority value among the packets competing for said time slot.

Abstract: A method of operation of a communications network comprises receiving a plurality of dynamic radio traffic requests from wireless communications nodes. The traffic requests comprise requests for backhaul traffic received from radio base stations, and requests for fronthaul traffic to digital units received from remote radio units. The radio traffic requests are translated into corresponding transport layer requirements. Transport network resources are requested for the radio traffic based on the transport layer requirements, which meet the radio traffic requests.

Abstract: A method for managing traffic of a plurality of packets in a plurality of packet flows transmitted using a time-slotted interface. The packet flows traverse a plurality of switches of a transport network according to an assigned path from a source node to a destination node. The method comprises determining (202) an end-to-end latency of a plurality of packets traversing a current switch in packet flows and assigning (204) priority to packets to the packets traversing the current switch, wherein a priority value of a packet depends on the determined end-to-end latency of said packets. The method further comprises allocating (206) a time slot in an output interface of the current switch to the packet having the highest priority value among the packets competing for said time slot.

Abstract: A data center network node (28) comprises one or more switch (18,19,22,23) configured to link an optical transceiver (16,17) to an optical connection comprising a multi-core optical fiber (30) having a plurality of cores (31). For each core (31), the one or more switch (18,19,22,23) is configurable between a first configuration in which an optical signal on a said core (31) of the multi-core optical fiber bypasses the optical transceiver and a second configuration in which the optical transceiver is optically linked to the said core (31) of the multi-core optical fiber (30).

Abstract: A data center network node (13) comprising a first data connection (22) for connecting at least one server to a conventional subnetwork comprising at least one of a switch or a router, an optical transceiver (14) comprising a transmitter (16) and a receiver (17), a second data connection (23) for connecting the at least one server to the optical transceiver, a switching arrangement (21) for linking the optical transceiver (14) to an offload subnetwork (10), the switching arrangement configurable between a first configuration (24) in which the offload subnetwork bypasses the optical transceiver and a second configuration (28) in which the optical transceiver is optically linked to the offload subnetwork.

Abstract: A network node (15) is configured to switch data packets between a Remote Radio Unit (2) and a Digital Unit (4). The network node comprises one or more input port (33) configured to receive said data packets (52a) and receive further packets having a destination other than one of a Remote Radio Unit and a Digital Unit. One or more output port (35) is configured to transmit said data packets and said further packets. A scheduler (31) is configured to control transmission from the output port according to a scheduling cycle (41a). The scheduler is configured to schedule only said data packets to be transmitted in a first period of the scheduling cycle, and schedule one or more of said further packets to be transmitted in a separate second period of the scheduling cycle.

Abstract: A virtualization system (1) comprising a baseband processing arrangement (11,12). The virtualization system is configured to provide a plurality of virtual machines (41,42), each virtual machine having an allocation of baseband processing capacity provided by the baseband processing arrangement for serving remote radio units (6). The virtualization system is configured to dynamically re-allocate baseband processing capacity between virtual machines (41,42) based on at least one parameter related to radio domain requirements of the remote radio units (6).

Abstract: An optical node (100) is disclosed. The optical node (100) comprises first and second line ports (104, 106) for Wavelength Division Multiplexing (WDM) signals and first and second pluralities of local add/drop ports (108, 110) for optical signals. The optical node further comprises a wavelength selective switch (112), coupled between the first and second line ports (104, 106) and configured to drop optical signals from a WDM signal traversing the optical node between the first and second line ports (104, 106), and a node optical combiner (114) coupled between the first and second line ports (104, 106) and configured to add optical signals to a WDM signal traversing the optical node between the first and second line ports (104, 106).

Abstract: A method for managing traffic of a plurality of packets in a plurality of packet flows transmitted using a time-slotted interface. The packet flows traverse a plurality of switches of a transport network according to an assigned path from a source node to a destination node. The method comprises determining (202) an end-to-end latency of a plurality of packets traversing a current switch in packet flows and assigning (204) priority to packets to the packets traversing the current switch, wherein a priority value of a packet depends on the determined end-to-end latency of said packets. The method further comprises allocating (206) a time slot in an output interface of the current switch to the packet having the highest priority value among the packets competing for said time slot.

Abstract: A method of scheduling transmission of a data flow in a data center network comprising a plurality of network nodes and links. The method comprising, at a network controller receiving (14) a transmission request for a data flow, obtaining (15) a tolerated time interval for the data flow, and scheduling (16) transmission of the data flow within the tolerated time interval and without contention with other transmissions.

Abstract: A method for switching data signals transmitted over a transport network is disclosed. The method comprises receiving a plurality of input data signals of a first signal type wherein the plurality of data signals of the first signal type comprises data signals exchanged between a Radio Equipment and a Radio Equipment Controller and aggregating the plurality of input data signals into an aggregated first data signal. The method also comprises receiving a second data signal of a second signal type different to the first signal type, and multiplexing the first data signal with the second data signal to form a combined data signal. The method further comprises forwarding the combined data signal to the transport network. Multiplexing the first data signal with the second data signal comprises, for a frame of the combined data signal, allocating the first data signal to a portion of the frame reserved for the first data signal, and allocating the second data signal to a remaining portion of the frame.

Abstract: A method (10) of encapsulating digital communications signals for transmission on a communications link, comprising steps: a. receiving a first signal of a first signal type and comprising a first clock signal and receiving a second signal of a second signal type, different to the first, and comprising a second clock signal different to the first clock signal, each clock signal having a respective clock value and accuracy (12); b. obtaining the first clock signal (14); c. obtaining a difference between at least one of the clock values of the clock signals and the accuracies of the clock signals (16) and buffering the second signal for a time at least long enough to compensate for the difference (18); and d. assembling the first signal and the buffered second signal into a frame comprising an overhead and a payload comprising a first portion and a second portion, mapping the first signal into the first portion and the second signal into the second portion (20), wherein step d.

Abstract: A network node (30) for a radio access network, wherein the network node comprises a switch system (35) configured to switch traffic for a plurality of base stations (3, 5; 8) of the radio access network. The switch system (35) is configured to provide for communication between a remote radio unit (3) and a baseband processing unit (5, 12) of the said plurality of base stations. The switch system (35) is configured to provide for communication between a first base station (8) and a second base station (3, 5) of said plurality of base stations. At least one of the first or second base station is a radio base station (8) comprising baseband processing.

Abstract: Configuring a node (410, A-I, L-O) of a synchronization network, involves determining information about synchronization sources of a plurality of synchronization trails for passing synchronization information from the synchronization source (A, L, O, PRC) to the node to provide a synchronization reference. After determining automatically (210, 250, 330, 335, 340) synchronization transmission characteristics of trails (EP, FG, GH, HM, MN, OF, FI, IH) which use packet-based communication, the trails are compared automatically (240, 370), using their source information and their synchronization transmission characteristics, for selecting winch of these trails to use for providing the synchronization reference for the node (N).

Abstract: A data center network node comprising at least one server connection for connecting to a server 6, a connection 7 for connecting the at least one server 6 to a first subnetwork. The first subnetwork is a conventional subnetwork which comprises at least one of a switch or a router. The node further comprises an optical receiver array 20 for connecting the node to an optical offload subnetwork, wherein the optical receiver array 20 comprises a plurality of optical receivers. The array is configured such that each receiver is connectable to an optical path within a multi-path optical connection. The node further comprises an optical transmitter array 23 for connecting the node to an optical offload subnetwork. The optical transmitter array comprises a plurality of optical transmitters. The array is configured such that each receiver is connectable to an optical path within a multi-path optical connection.

Abstract: A method for switching data signals transmitted over a transport network is disclosed. The method comprises receiving a plurality of input data signals of a first signal type wherein the plurality of data signals of the first signal type comprises data signals exchanged between a Radio Equipment and a Radio Equipment Controller and aggregating the plurality of input data signals into an aggregated first data signal. The method also comprises receiving a second data signal of a second signal type different to the first signal type, and multiplexing the first data signal with the second data signal to form a combined data signal. The method further comprises forwarding the combined data signal to the transport network. Multiplexing the first data signal with the second data signal comprises, for a frame of the combined data signal, allocating the first data signal to a portion of the frame reserved for the first data signal, and allocating the second data signal to a remaining portion of the frame.

Abstract: An optical switch (10) comprising: input ports (12, 14) arranged to receive optical signals from directions D1 to Dn; output ports (16, 18) arranged to output optical signals to the said directions; drop ports (20); add ports (22); a first switch array (24) arranged to receive from a first said input port (12) optical signals at a plurality of wavelengths, and comprising switch elements (26) each arranged to selectively direct optical signals to a respective drop port.