Abstract: There is provided a compression method for TDM frames transported over a packet network. The method is based on mapping of allocated TDM slots but not all un-allocated slots into a transport structure, which thereby reduces the needed amount of data transported over packets and hence reduces the required packet rate and packet capacity during transport of the TDM frame. The mapping is further arranged to allow dynamic changes of packet rate and packet capacity, thus the mapping is performed such that a working size of the transport TDM frame is allowed to increase or decrease over time. Further, mechanisms to lower experienced delay for low-rate signals are provided.

Abstract: An apparatus for switching data between a first set of bitstreams and a second set of bitstreams, each of said bitstreams being divided into recurring frames and each of said recurring frames being divided into time slots, is disclosed. The switch comprises a first set of switching elements, at least one intermediate set of switching elements, and a last set of switching elements. Each switching element comprises a number of input ports and a number of output ports. The input ports of the first set of switching elements are arranged to receive the first set of bitstreams and the output ports of the last set of switching elements are arranged to provide said second set of bitstreams. Furthermore the switching elements are arranged so that there are more than one path from a switching element in the first stage to a switching element in the last stage.

Abstract: The present invention relates to methods for changing the bandwidth of a circuit switched channel in a time division multiplexed network, wherein said channel comprises a set of time slots within each recurring frame of a bitstream between a first node and a second node. According to the invention one or more additional time slots within each recurring frame of said bitstream are reserved, including using, during a period of time, only said set of time slots for transmitting payload data pertaining to said channel while providing, during said period of time, information indicating that said one or more additional time slots are currently not used for transferring payload data. After said period of time, said set of time slots is used as well as said one or more additional time slots on said bitstream for transmitting payload data pertaining to said channel.

Abstract: The present invention refers to a method for controlling resources on a communication link that transports data in time slots, wherein access to the time slots is distributed among nodes connected to the link. A state of access to a set of one or more of the time slots may be determined by the step of sending an inquiry to one or more of the nodes and receiving one or more replies to the inquiry from the one or more nodes. The inquiry and replies may be related to whether or not any one of the one or more nodes considers itself as currently having access to any one or more of the set of time slots.

Abstract: The present invention refers to a method and an apparatus for synchronizing operation at a node of a communication network. According to the invention a phase relationship between an output frame synchronization signal and an input frame synchronization signal is controlled by the adjustment of a phase difference between the output frame synchronization signal and a node synchronization signal.

Abstract: The present invention relates to methods for changing the bandwidth of a circuit switched channel in a time division multiplexed network, wherein said channel comprises a set of time slots within each recurring frame of a bitstream between a first node and a second node. According to the invention one or more additional time slots within each recurring frame of said bitstream are reserved, including using, during a period of time, only said set of time slots for transmitting payload data pertaining to said channel while providing, during said period of time, information indicating that said one or more additional time slots are currently not used for transferring payload data. After said period of time, said set of time slots is used as well as said one or more additional time slots on said bitstream for transmitting payload data pertaining to said channel.

Abstract: The present invention relates to methods for changing the bandwidth of a circuit switched channel in a time division multiplexed network, wherein said channel comprises a set of time slots within each recurring frame of a bitstream between a first node and a second node. According to the invention one or more additional time slots within each recurring frame of said bitstream are reserved, including using, during a period of time, only said set of time slots for transmitting payload data pertaining to said channel while providing, during said period of time, information indicating that said one or more additional time slots are currently not used for transferring payload data. After said period of time, said set of time slots is used as well as said one or more additional time slots on said bitstream for transmitting payload data pertaining to said channel.

Abstract: The present invention refers to an apparatus providing routing of asynchronous traffic in a circuit switched synchronous time division multiplexed network, said apparatus comprising an interface (12) providing access to a multi-channel bitstream carrying isochronous channels; routing means (26) for providing routing of data packets; and a communication medium (24) interconnecting said interface and said routing means. According to the invention, said interface (12) comprises means (18) for deriving data packets received in at least one of said isochronous channels, means (22) for transmitting only header portions of said data packets to said routing means via said communication medium (24), means (20) for temporarily storing at least body portions of said data packets, and means (22, 32) for forwarding said data packets in accordance with routing instructions received from said routing means.

Abstract: The present invention refers to methods for establishing control signaling between nodes connected to the same communication link, said link carrying a bitstream that is divided into frames, each frame in turn being divided into time slots, said time slot being allocatable to define circuit switched channels. According to the invention, all nodes connected to said link using, at link start-up, the same predefined time slot or set of time slots in said frames to receive control signaling messages from and transmit control signaling messages to nodes connected to said link. The nodes then establishes, using control signaling via said predefined time slot or set of time slots, respective control channels, defined by respective time slot or set of time slots in said frames, reserved for transmission of control signaling messages from each respective one of said nodes.

Abstract: The present invention refers to methods and apparatuses for providing synchronization in a time division multiplexed network, wherein data is transferred on multi-access bitstreams in circuit-switched channels that are defined by respective time slots of regularly recurrent frames of said bitstreams, said frames being defined by regularly recurrent frame synchronization signals transferred on said bitstreams. According to the invention an auxiliary regularly recurrent frame synchronization signal is generated and selected as a basis for defining said frames on a bitstream if the frame synchronization signal that is used as a basis for synchronizing said frames during normal operation is not detected in accordance with an expected frame rate.

Abstract: An apparatus for switching data between a first set of bitstreams and a second set of bitstreams, each of said bitstreams being divided into recurring frames and each of said recurring frames being divided into time slots, is disclosed. The switch comprises a first set of switching elements, at least one intermediate set of switching elements, and a last set of switching elements. Each switching element comprises a number of input ports and a number of output ports. The input ports of the first set of switching elements are arranged to receive the first set of bitstreams and the output ports of the last set of switching elements are arranged to provide said second set of bitstreams. Furthermore the switching elements are arranged so that there are more than one path from a switching element in the first stage to a switching element in the last stage.

Abstract: A technique is provided for allocating access to time slots used for transferring data between nodes in a time multiplexed network, whose bandwidth is divided into cycles. The cycles are in turn divided into control slots for control signaling and data slots for transferring data. The slots allocated to a primary home node may be temporarily allocated to a temporary home node, in which case the temporary home node, instead of the primary home node, then temporarily has the write access to the slots. The slots may subsequently be reallocated to the primary home node. In particular, the degree of temporary allocation of slots to a first node is evaluated. Then, the number of slots having the first node as a primary home node may be increased based upon the evaluation. This decreases the need for temporary allocation of slots within the network.

Abstract: The present invention relates to a method, a system and apparatuses for transferring data on a bitstream in a circuit switched time division multiplexed network, wherein said bitstream is divided into frames, each frame is divided into time slots, and said time slots are divided into control slots and data slots, and wherein an isochronous channel, comprising one or more data slots within each cycle of said bitstream, has been established between a first node and a second node of said network. According to the invention, said bitstream is provided with data distinguishing each data slot, within said channel, that contains non-valid data as a result of said first node not being able to transmit valid data into said each data slot.

Abstract: The present invention relates to the transferring of data via a shared medium between nodes in a time multiplexed network, wherein said data is transferred in time slots in one or more bitstreams. To obtain an efficient network, the synchronisation of parallel bitstreams is of great importance. A high degree of utility is provided by time slot reuse. The above-mentioned characteristics are obtained by regenerating each bitstream as a whole in a node. This also solves problems with dispersion, attenuation, clock gap and clock extraction. The invention is preferably provided using WDM in a DTM network.

Abstract: The present invention relates to the transferring of data via a shared medium between nodes in a time multiplexed network, wherein said data is transferred in time slots in one or more bitstreams. To obtain an efficient network, the synchronization of parallel bitstreams is of great importance. A high degree of utility is provided by time slot reuse. The above-mentioned characteristics are obtained by regenerating each bitstream as a whole in a node. This also solves problems with dispersion, attenuation, clock gap and clock extraction. The invention is preferably provided using WDM in a DTM network.

Abstract: A method and an apparatus for switching data between a set of input bitstreams and a set of output bitstreams in a circuit switched time division multiplexed network is presented. Each bitstream is divided into recurring frames and each frame is divided into time slots. Each one of the input bitstreams is received, and frames of time slot data thereof are temporarily stored in a set of memories. Each of the memories is used for storing frames of a respective bitstream of the input bitstreams. For each frame of each one of the output bitstreams, and sequentially in accordance with the order that the time slot data are to be transmitted in the respective output frame, time slot data is selectively read from frames presently temporarily stored in the set of memories, and is then transmitted into allocated time slots of the output bitstreams.

Abstract: The present invention refers to transferring of data in a mobile communication network. According to the invention, data is transferred between one or more mobile switching centers and one or more of a plurality of base stations via one or more controllers, each controlling a respective group of the plurality of base stations, at least in part using a Dynamic Synchronous Transfer Mode type network.

Abstract: The present invention relates to a method and an arrangement for dynamic signalling in a network, such as a Dynamic Synchronous Transfer Mode (DTM) network. The network's bandwidth is divided into cycles, which in turn are divided into control slots for control signalling and data slots for transferring data. Preferably, each or certain nodes have a node controller, which control the access to slots. According to the invention data slots are converted into control slots, called dynamic control slots, or control slots are converted into data slots in order to change the signalling capacity of a node. The dynamic control slots may be used for point-to-point, multicast or broadcast signalling.

Abstract: The present invention relates to a method and an arrangement for centralized and distributed management of capacity (communication resources) in a circuit switched network with shared medium topology (e.g. bus or ring topology), of DTM type (digital synchronous transmission), in which the network use the capacity which are divided into cycles, which in turn are divided into control time slots for signaling and data time slots for data transmission, and where each data time slot is associated with a token. In the centralized version is a first node, named server node, assigned token corresponding to the in one direction sent data time slots on the communication link (e.g., bus or ring). A second node requests token corresponding to a certain capacity from the server node and the server node reserves and transfers tokens corresponding to the capacity requested to the other node in the case the server node has requested capacity unused.

Abstract: The present invention relates to a defragmentation method and arrangement for increasement of the average block size of free tokens in the nodes of a DTM (Dynamic Synchronous Transfer Mode) network. The defragmentation comprises defining a home node for each token at network startup in such way that the tokens sharing the same home node will always define at least partly a continuous slot range, sending back free tokens to home nodes when a significant time has passed and, merging two or more slot-consecutive tokens with the same slot range into a single token when existing in the free pool of a node. The defragmentation can be realized in a central or a distributed token management scheme.