Roke Manor Research Limited

Siemens Aktiengesellschaft

Andrew Timothy Hayter

Simon Paul Davis

Wolfgang Fischer

Thomas Worster

Eugen B Wallmeier

Ian B Stewart

Ian Lesseter Phillips

Paul P Momtahan

Christopher Paul Urry

Paul Parshee Momtaham

Michael John Excell

A broadband telecommunications switch ( ), for switching packets of data received on a plurality of input ports ( ) to plurality of bandwidth limited output ports ( ), comprising for each input port ( ) a control processor ( ) which operates to send request data for each of a plurality of switching periods to each output port ( ), which request data is representative of a requirement for communications bandwidth from said output ports ( ) sufficient to accommodate packets of data received at said input ports ( ) for switching to said output ports ( ) for the switching period. Each of said bandwidth allocators ( ) responds to said request data by generating bandwidth allocation data appertaining to an allocation of a share of the bandwidth of the output port ( ) to the input port ( ), which share of bandwidth said input port ( ) uses to switch data from said input ports to said output ports during said switching period.

Broadband telecommunications switch

A broadband telecommunications system comprises at least one broadband telecommunications switch, and a data transmitter coupled to the broadband telecommunications switch and to each of a plurality of data sources. The system operates to communicate date from the data sources to destinations in the form of a plurality of cells, the communication being arranged to satisfy predetermined transmission parameters. The transmission parameters include an initial cell rate representative of a maximum rate at which data from the data sources may be initially communicated to the telecommunications switch, when the sources become active. By providing the telecommunications switch with a bandwidth allocator which operates to calculate an available bandwidth for allocation between the plurality of data sources in accordance with a number of the data sources which are idle during a predetermined period scaled respectively by each initial cell rate, and operates to allocate the available bandwidth between active data sources, a data storage requirement may be substantially reduced.

Broadband telecommunications system

An apparatus for queuing and scheduling ATM cells across an ATM switch comprises sustainable cell rate calendar connected in series with a peak cell rate calendar wherein cells are scheduled independently in each. The sustainable cell rate calendar guarantees the maximum ATM cell delay is not exceeded. The ATM cells are not placed on the peak cell rate calendar unless the peak cell rate threshold might be exceeded. In this case the cell is scheduled on the peak cell rate calendar and it is this that determines when the cell is sent. In this way, it is possible to guarantee absolute minimum and maximum cell rates of a connection.

ATM queuing and scheduling apparatus

AN ATM communication system having both dynamic bandwidth allocation capability comprising storage mechanism for DBA traffic, the storage mechanism further including dedicated storage mechanism for ABR traffic. The system being such that ABR bandwidth requests are allocated after all other DBA bandwidth allocations have been satisfied. A device for interrupting an ABR transmission, before a bandwidth allocation within which the said ABR transmission is included has been fully used, for the transmission of other higher priority DBA traffic is provided.

ATM communication systems

An apparatus having a buffer store connected to an input line upon which ATM cells are received, and an output line upon which ATM cells are transmitted is provided. A control device receives, for each cell, a channel identifier and a path identifier from which a first signal is generated indicative of a maximum delay value which is applied to the buffer store and used to schedule the particular cell for transmission on a calendar controlling a sustainable cell rate. The control device generates a second signal indicative of a minimum delay value which is applied to the buffer and, in conjunction with the first signal, is used to schedule the particular cell for transmission on a calendar controlling the peak cell rate. The apparatus can also handle routing information, where a group of channel connections define a Route which share a peak cell rate for the Route and are scheduled on the peak cell rate calendar.

Apparatus and method for ATM queuing and scheduling

An ATM communication system including an ATM switch having input and output ports is provided. Each input port is fed from an input port server and each of the output ports are arranged to feed an output port server. The input port servers include buffer stores, one for each of the output ports, to which data is transmitted through the switch. Each buffer store in the input port servers is arranged to interrogate the output ports server, with which it communicates before the transmission of data, to determine whether the output port server data handling capacity is available. The ATM communication system includes a transmitting devices for unicast traffic and multicast traffic. The transmitting device includes an output time slot control device and a scheduling device arranged to allocate a time slot for the transmission of each unicast traffic cell, and for calculating when a time slot is available for transmission of a multicast traffic cell. The output time slot control device includes a store for storing information identifying the time slot and for reserving that time slot for the transmission of a multicast traffic cell.

Apparatus and method of processing bandwidth requirements in an ATM

An ATM communication system has an ATM switch having a plurality of input ports and a plurality of output ports, each of the input ports being fed from an input port server and each of the output ports being arranged to feed an output port server. The input port servers each have a plurality of buffer stores, one for each of the output ports to which output port data is transmitted through the switch. Each buffer store in the input port servers is arranged to interrogate the output port server with which it communicates by a bandwidth request before the transmission of data. This determines whether output port server data handling capacity is available, whereby ATM switch operation during periods of peak traffic is facilitated. The system includes a queuing arrangement for bandwidth requests received during periods when there is no available bandwidth capacity, the arrangement being such that requests are released in a predetermined order when capacity becomes available.

ATM communication system with interrogation of output port servers for

An ATM signal processor system for processing ATM data cells which in combination define a data package wherein the last cell of a package is characterized by an identifying code. The cells of different data packages are multiplexed to provide a serial data stream. A server and a buffer store via which the server is fed with the serial data stream are provided. The buffer store has a threshold capacity beyond which cells are discarded. A discarded cell identifier/rejecter serves to identify and store the identity of a data package with which a discarded cell is associated so as to be set thereafter to reject subsequently received cells with the same data package identity until being reset upon receipt of the last cell of the package as indicated by its characteristic identifying code.

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Southampton, United Kingdom

Andrew Timothy Hayter