Abstract: An STM telecommunications switch comprising a plurality of parallel data switching planes and a parallel control planes, each plane having an equal number of input ports and output ports and a central switching unit to switch each input port to any output port and wherein the data is switched in octets.

Abstract: A partially interconnected network has a plurality of topological nodes, each of the topological nodes having at least three direct point-to-point topological links connected to other topological nodes. Each of a proportion of the plurality of topological nodes is connected to one of a group of point-of-presence (PoP) units. The group of PoP units is arranged to provide access to a selected service or services, one or more of each of the at least three direct point-to-point topological links from each topological node not being connected to one of a group of PoP units connecting to one or more than one of the plurality of topological nodes being connected to one of the group of PoP units. There is at least one choice of routing between any two topological nodes, the choice of routing being either via two topological links connected in series at another topological node or a direct point-to-point topological link between the two topological nodes.

Abstract: A network has a plurality of nodes, wherein at least one of the plurality of nodes includes a switch arranged to carry out a Simple Transit Core Function and three or more of the plurality of nodes include a Single Link Interface which Single Link Interface has associated Output Attributes and/or Input Cognizant Attributes. Each Simple Transit Core Function at one node is not logically connected to another Simple Transit Core Function at another node. Each Simple Transit Core Function at one node is logically connected to at least three Single Link Interfaces at other nodes. The nodes including Single Link Interfaces which are connected to one instance of a node arranged to carry out a Simple Transit Core Function are controlled by respective Intercommunicating Connection Acceptance Control Processes according to the respective Output Attributes and/or Input Cognizant Attributes.

Abstract: A partially interconnected network comprises a plurality of allocated nodes, each allocated to one of a number of areas, a plurality of star nodes, and point-to-point interconnections between the allocated nodes and the star nodes. The number of areas with allocated nodes interconnected to an individual star node forms the number of routes from an individual star node, each of a proportion of the plurality of star nodes having connected thereat one of a group of point of presence (PoP) units. The group of PoP units is arranged to provide access to a selected service or selected services. The allocated nodes of a first of the areas are interconnected to a set comprising some, but not all, of the star nodes. Further of the areas are similarly interconnected to further sets each comprising star nodes.

Abstract: A communications network using Asynchronous Transfer Mode has a head end unit connected to a plurality of groups of network terminations wherein the frequency spectrum of the network is divided into a number of frequency bands, one band of which forms a start-up band used for start-up and configuration of a network termination, the remaining bands each being used for communication between the head end unit and the network terminations within a group subsequent to start-up and configuration. The network may be a Passive Optical Network.

Abstract: An optical communications network having a Head End Unit connected to a plurality of groups of Network Termination Equipments (NTE) and/or Optical Network Units (ONU), the downstream communication being by Time Division Multiplex, has a group multiplexed onto a stream and a plurality of streams are combined into a higher speed multiplex and the upstream communication is by Time Division Multiplex Access.

Abstract: Video on Demand allows, for example, a coded TV signal or film to be transmitted to a subscriber over a standard two-wire metallic telephone line. A similar apparatus for connecting unidirectional mobile data output to a destination via a standard metallic telephone line, the apparatus comprising a High Bandwidth Subscriber Link Transmitter Unit connected between the data source and a connection point on the telephone line and a High Bandwidth Subscriber Link Receiver Unit connected to a further connection point on the telephone line would enable a signal such as from a video camera to be input at or subscriber terminal and transmitted over a metallic telephone line.

Abstract: In a telecommunications time division multiple (TDMA) optic network system, network termination equipments (NTE's) are enabled to communicate with a head end by the NTE encoding a message as a signal including error correction on the existing signal traffic, monitoring the errors at the head end and extracting the message from the errors.

Abstract: Statistical multiplexing gain is desirable on ATM links, especially on high-cost international links, and is provided where STM traffic is carried as cells on an ATM bearer. The cells have a bit-stream based AAL format including a map for indicating any STM idle channels. The STM idle channels are not transmitted in the cells. Preferably, the format is AAL Type 1 for structured data, and the map is carried using an extension mechanism of that format.

Abstract: An ATM telecommunications switch includes a plurality of parallel data switching planes and a parallel central plane, each plane having an equal number of input ports and output ports and a central switching unit to switch each input port to any output port. The switch further includes a first rotator to connect each input port cyclically to each timeslot of the central switching unit and a second rotator to connect each timeslot of the central switching unit cyclically to each output port.