摘要:
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. The architecture comprises a plurality of TDM interfaces, a plurality of conversion means for converting from time division multiplexed mode to a plurality of packet streams; a plurality of packet streams switching devices and a plurality of network service provider devices.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
Communicative services are transported over a TDMA or TDM access network by packetising the services into minicells which minicells are transported within minislots created by subdivision of the TDM time slots. For low bit rate communicative services only, mini-slots are allocated periodically rather than in the blocks that are allocated to high bit rate services. The packetisation delay inherent within the transport layer can be significantly reduced for these low bit rate services.
摘要:
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.
摘要:
A data structure, such as a telecommunications connection map, comprises at least one list of data elements which are stored in a predetermined sequence of locations of a memory device. The structure is updated by moving a portion of the list through the sequence of memory locations so as to insert a new element into, or delete or change an existing element at, a particular position in the structure while maintaining the order of the list. Elements of the structure are accessed in the sequence in which they are stored and the structure is updated during the accessing of the structure by moving elements through the sequence of memory locations. A particular application of this invention is in maintaining a connection map for a telecommunications switch, the map storing connection instructions defining into which ATM cell payload received narrowband call data is assembled.
摘要:
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.
摘要:
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.