Abstract: A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The visual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.

Abstract: Traffic from a number of different service type users is multiplexed into minicells for transmission over an ATM link. Service type information is transmitted in a service specific field and is stored. This stored information is used to derive length information to delineate the different length user minicells. The technique occupies less bandwidth than the conventional methods for transmitting cell length information.

Abstract: A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The visual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.

Abstract: An improved architecture in a circuit switched communications network is provided in which a plurality of network service provider devices, eg intelligent peripherals are arranged to provide network service data to a plurality of time division multiplex circuits and trunks by converting these circuits and trunks to streams of packets, and providing network service data packetized in a set of network service data packet streams to the circuit packet streams without incurring delays to the circuit packet streams. The circuit packet streams may be duplicated and forwarded to the network service provider devices without incurring delay to the ongoing through put packetized circuits, and similarly packet streams containing network service data may be superimposed into the circuit packet streams, without the requirement for the circuit packet streams to be switched to the network service provider devices.

Abstract: Traffic from a number of different service type users is multiplexed into minicells for transmission over an ATM link. Service type information is transmitted in a service specific field and is stored. This stored information is used to derive length information to delineate the different length user minicells. The technique occupies less bandwidth than the conventional methods for transmitting cell length information.

Abstract: Point to point protocol (PPP) traffic is transported over an asynchronous transport link by encapsulating the traffic in AAL2 minicells and transporting the minicells in a single virtual circuit. Minicells from a number of users can be multiplexed in the same virtual circuit.

Abstract: A method of adapting synchronous time division multiplexed (TDM) traffic at an interface between a synchronous network in which the traffic is transported in frames identified by corresponding pointers and labels and an asynchronous network in which the adapted traffic is transported in cells, the method comprising mapping said synchronous frames into primary multiplexed groups, mapping each said primary multiplexed group into traffic cells in a respective asynchronous virtual channel, and providing that virtual circuit with a corresponding virtual channel indicator, and wherein said pointers and labels are mapped into one or more separate asynchronous cells for transport ahead or said traffic cells.

Abstract: An interface arrangement provides interfacing between a frame based telecommunications network in which traffic is transported in frames and an asynchronous network in which traffic is transported in cells or packets. Each TDM frame supports a plurality of data structures each comprising one or more channels. Credits corresponding to bandwidth entitlement are issued at a substantially constant rate and are assigned to the data structures according to the size of those structures by a connection control. Each data structure is accorded a threshold number of assigned credits, and when this number has been reached, the data structure is assembled into cells or packets for dispatch into the asynchronous network.

Abstract: A method and apparatus for handling persistence measurement of channel associated signaling for a plurality of line circuits, eg, T1, E1, OC3, STM 1 circuits, which extracts channel associated signaling data from a plurality of line circuits; assembles the channel associated signaling data into a data frame; contains the data frame in a suitable carrier, eg, an AAL 0 cell; monitors a continuous stream of the data frames, to check for changes in line status; and generates an event message data frame when a persistent change of line state has been detected. The extracting of associated signaling data may be provided on a separate card to a call control processor, and using separate processor functionality.

Abstract: The invention relates to a method and apparatus for multiplexing traffic from a plurality of fixed bit rate sources over an ATM network. The traffic from the fixed bit rate users is multiplexed to form a TDM trunk group which is assembled into AAL2 minicells prior to being converted to ATM cells for transmission on the ATM network. By combining the fixed rate traffic sources into a TDM trunk group and then mapping the trunk group into AAL2 minicells, it is possible to improve efficiency of fixed bit rate traffic transmission using the ATM protocol.

Abstract: An improved architecture in a circuit switched communications network is provided in which a plurality of network service provider devices, eg intelligent peripherals are arranged to provide network service data to a plurality of time division multiplex circuits and trunks by converting these circuits and trunks to streams of packets, and providing network service data packetized in a set of network service data packet streams to the circuit packet streams without incurring delays to the circuit packet streams. The circuit packet streams may be duplicated and forwarded to the network service provider devices without incurring delay to the ongoing through put packetized circuits, and similarly packet streams containing network service data may be superimposed into the circuit packet streams, without the requirement for the circuit packet streams to be switched to the network service provider devices.

Abstract: An improved architecture in a circuit switched communications network is provided in which a plurality of network service provider devices, eg intelligent peripherals are arranged to provide network service data to a plurality of time division multiplex circuits and trunks by converting these circuits and trunks to streams of packets, and providing network service data packetized in a set of network service data packet streams to the circuit packet streams without incurring delays to the circuit packet streams. The circuit packet streams may be duplicated and forwarded to the network service provider devices without incurring delay to the ongoing through put packetized circuits, and similarly packet streams containing network service data may be superimposed into the circuit packet streams, without the requirement for the circuit packet streams to be switched to the network service provider devices.

Abstract: There is disclosed a method and a system for multiplexing data from a plurality of user data sources across an ATM adaption layer type-2 connection, in which a multiplexed trunk group extends across a plurality of common part sub-layer protocol data unit (CSU-PDU) mini-cells, and across a plurality of ATM cells. Large trunk groups are assembled by use of a single bit continuation indicator in the service specific convergence sub-layer header (SSCS) of successive CPS-PDU mini-cells. A packet payload type field (PPT) of the common part sub-layer (CPS)/service specific convergence sub-layer (SSCS) is used to indicate timing of changes in number of user data sources in a trunk group and provides for robust error recovery on loss of a single CPS-PDU mini-cell.

Abstract: In an adaptation layer switching network, functional partitioning is provided by providing a separation between service specific sublayers (SSCS), common part sublayers (CPS) and transport convergence. This enables the support of a range of SSCS functions via common set of CPS blocks.

Abstract: An arrangement for interfacing between TDM and ATM networks consists of a family of devices that comprises two groups. The first group comprises devices that perform multiplexing, segregation and routing field translation for the respective traffic type. They may also remove or substitute an outermost layer of encapsulation. These first group devices are bi-directional and output buffered with respect to the network. The second device group comprises devices that perform format conversions between the service payload (voice, video or data) and an adaptation layer control format. These second group devices are also bi-directional and buffering depends on the particular function, e.g. real-time, segmentation.

Abstract: A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The vitual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.

Abstract: An interface arrangement provides interworking between packet (IP), time division multiplex (TDM) and asynchronous (ATM) networks, and incorporates a TDM framer providing an interface to the TDM network, a packet framer providing an interface to the packet network, and ATM adaptation function providing an interface to the ATM network. The ATM adaptation function comprises a set or suite of integrated circuit devices, the devices being partitioned by AAL functions into a first device set arranged to perform a common part sublayer function and a second device set arranged to perform service specific sublayer functions. The composition and nature of the device sets can be chosen to match the traffic types and quality of service requirements.

Abstract: In a communications system in which narrow band, e.g. voice, channels are carried in packet form over an asynchronous network, each channel is encoded to reduce its bit rate so as to reduce demands on band width. The encoding of each channel is effected via an algorithm selected from a group of algorithms associated with that channel. The algorithms forming the group are identified to a receiver station performing a decoding function via information provided in each packet header. The particular algorithm currently in use is determined implicitly from the packet length or from a combination of the packet length and a discriminator field provided in the packet header.

Abstract: A telecommunications system comprises an asynchronous transfer mode (ATM) network having uncommitted bandwidth, and a plurality of adaptive grooming routers (AGR) coupled to the network. The AGRs comprise a group adapted to function as a virtual transit exchange whose fabric and control are distributed over the group. The virtual comprising the AGRs incorporates independent connection control and call routing functions and has means for determining the current system status whereby to set up narrow band connections across the ATM network based on that status determination.