Abstract: A packet scheduling system for use in a switching node of a high speed packet switching network. Incoming packets are enqueued in connection queues. Each connection is classified as red (exceeding traffic profile) or green (within traffic profile). QOS priority is also identified for each connection. Packets are dequeued for transmission as a function of priority class and connection class. Higher priority class connections have priority over lower priority class connections. Within a given priority class of connections, green connections have priority over red connections. Round robin scheduling is used for packets from connections in the same priority and connection class. In addition, a dynamic priority coupling mechanism is provided to prevent red higher priority traffic from blocking green lower priority traffic.

Abstract: Process for transmitting compressed voice circuits over a packet switching network of the type comprising a plurality of switching nodes (SW-1 to SW-7) interconnected by connection lines and including at least an end switching node (SW-1) connected to a source exchange telephone device (PABX A) and another end switching node (SW-3) connected to a destination exchange telephone device (CX), and comprising the steps of receiving from the source exchange telephone device a sequence of uncompressed frames wherein each frame contains n slots containing each J bytes respectively associated to J voice circuits, compressing the data bits of each voice circuit in order to build a packet containing J compressed voice circuits, and providing this packet to the end switching node for transmission to the destination exchange telephone device.

Abstract: Adaptive bandwidth allocation for Non-Reserved traffic over high speed transmission links of a digital network is operated through regulation of data packet transfers over network nodes/ports including input/output adapters connected through a switching device. A network node is assigned with a Control Point computing devise (CP) storing a Topology Data Base containing an image of the network. This Data Base is periodically and at call set up updated by Topology Data Base Update messages (TDUs) including an Explicit Rate parameter for link l indicating the current available bandwidth on link l, and a parameter NNRl indicating the number of Non-Reserved connections on link l. This information are used within each Adapter to periodically regulate the transmission bandwidth assigned to each Non-Reserved traffic connection within the network.

Abstract: A system for coding voice signal to optimize bandwidth occupation in a High Speed Packet Switching network while ensuring best voice transmission quality.The voice signal is first encoded using a conventional GSM like RPE/LTP coder providing first sub-frames of coded signal and tagging these first sub-frames as being non-discardable. In addition, a convenient difference between an RPE/LTP provided signal and a corresponding synthesized image is performed (see 36) and is also block encoded into second sub-frames which second sub-frames are tagged as being discardable sub-frames. Said second sub-frames when concatenated to corresponding first sub-frames provide so-called multirate frames. Then, when transmitting said multirate frames over the High Speed packet switching network, dropping discardable tagged data enables solution network congestion situations in any network node and at random with no significant disturbing effect over the voice communication operation.

Abstract: This method enables optimizing the time required for reestablishing connections between end users attached to a data communication network, which connections were disrupted due to a network failure. The network includes access nodes and transit nodes interconnected with network links/trunks (with no specific distinction being herein required between both designations of a communication line). The end users are attached to the network through access nodes and each said access node permanently stores an image of the current network trunk including the number N.sub.i of connections currently supported by said network trunk. Upon detection of a trunk failure, each access node supporting connections affected by said failure, is made aware of the total number (N.sub.i) of connections in each priority group affected by the failure, together with a network dependent parameter (TP) representing the elementary processing time required to reroute a single network connection.

Abstract: An apparatus and method for multicasting messages stored in data buffers of a data storage. Each message is composed of data stored in a plurality of the data buffers. Each data buffer is controlled and mapped to a unique direct control block (DCB) which stores information characterizing the data buffer. By chaining the DCBs variable length, messages can be generated. Indirect control blocks (ICB) stores information characterizing the data or messages duplicated and points to a DCB. A field in the DCB carries a count representing the number of times the message is to be duplicated.

Abstract: A method and system for reserving dynamically and in priority for each link of the network the exact amount of bandwidth necessary for the transmission of the network control traffic. An evaluation of the expected control traffic on each link of the network is performed in order to allocate a sufficient but minimum fraction of the link bandwidth and for allocating the maximum available bandwidth for the user traffic.

Abstract: A system adapts access to a packet switching network. A dynamic bandwidth adaptation continuously monitors the mean bit rate of a signal source and the loss probability of a connection in the network. A filtering means removes noise from the mean bit rate and loss probabilty. A test means determine whether the values fall within a pre-defined acceptable adaptation region in a mean bit rate, loss probability plane. Triggering means initiate bandwidth adaptation procedures when the values fall outside of the region which in turn, initiate means for acquiring a new connection bandwidth, and determining new parameters for the adaptation mechanism.

Abstract: A method and an apparatus for reducing the jitter and end-to-end delay on lines of a packet switching network conveying voice or video digitalized data for one or more connections between a local source and a remote source at a constant bit rate.The method and apparatus of the invention are for use in a voice or video processor of a voice or video processing server of a network node; the method and the apparatus provide a way of controlling the remote traffic rate from the remote source before accessing the processor without using an external clocking such as the network clock.The solution proposed by the invention consists in buffering the remote and local traffics to adapt the remote traffic rate to the local traffic rate, which is supposed having a limited jitter, while sequencing of the access of the buffered data to the processor.

Abstract: A method and system for optimizing data link occupation in a multipriority data traffic environment by using data multiplexing techniques over fixed or variable length data packets being asynchronously transmitted. The packets are split into segments including both a segment number and a packet number. The segments are dispatched, on a priority basis, over available links or virtual channels based on a global link availability control word indications, which control word is dynamically adjusted according to specific predefined conditions.

Abstract: A data processing method for efficiently transporting multimedia data packets of fixed and/or variable length over an Assynchronous Transfer Mode (ATM) network made to transport fixed length ATM cells including a fixed length user data payload and a fixed length ATM header. The data processing method includes concatenating said fixed and/or variable length user data and appending said concatenated data with a so-called trailer defining the various concatenated user data lengths and identifications, for being further split into ATM cells payloads before being transmitted over said ATM network.

Abstract: This invention deals with a method and system for dynamically adjusting the communication bandwidth assigned to an audio channel connection in a high speed digital network. More particularly, the invention is made to track the activity of a voice assigned connection (e.g. a PBX or PABX entry to the network), define a so-called activity bit for each block of audio channel signal and then dynamically adjust the assigned network communication bandwidth accordingly. Adjustment of the communication bandwidth is accomplished by integrating the audio channel activity bits through a predefined integration function, the result of which is then compared against predefined threshold values in order to determine an appropriate bandwidth setting for the audio channel.

Abstract: An explicit rate algorithm is disclosed for use in an end-to-end closed loop flow control algorithm for an ATM network which carries at least constant bit rate (CBR) traffic, variable bit rate (VBR) traffic and adjustable bit rate (ABR) traffic. The algorithm determines how much additional bandwidth is available for ABR traffic on an output link from a node and produces an explicit rate variable that can be forwarded to a source for the ABR traffic. Both the maximum and minimum bandwidths already reserved for all connections on the output link are determined. A single reserved bandwidth value is chosen within the range defined by the maximum and minimum reserved bandwidth values. The current utilization of the ABR input buffer for the node is also determined. The explicit rate variable is generated as a function of the link capacity, the reserved bandwidth value and the current utilization of the ABR input buffer.

Abstract: A method based on predefined connection priorities for assigning link bandwidth to a requesting user in a high speed digital network interconnecting network users through a path including network nodes connected through high speed links. According to this method, a predefined reservable link bandwidth is split into so-called nominal bandwidth portions and common bandwidth portions, both assignable to the same connections on a priority basis. Each of the common bandwidth priorities is individually related to a nominal bandwidth priority through a predefined relationship, making the common bandwidth priorities always lower than any nominal priority. In this way the requested link connection bandwidth, whatever be its nominal priority, is made preemptable primarily on all common bandwidth, thus avoiding the disruption of any network connection which is already established.

Abstract: An improved access control system for a memory system in which memory locations can be allocated to virtual output queues dedicated to output ports from the system. The virtual queues can be used to handle data of different priorities. Thresholds are defined for the occupancy of the overall memory and of each virtual queue. The access control system regulates the acceptance of data stored in input adapters by determining whether a back pressure situation exists for the data's target output adapter for the class of traffic to which the data belongs. A single-bit access-controlling back pressure signal is generated as a function of the occupancy level of either the overall memory or of the virtual queue defined for the target output adapter.

Abstract: Method and system for adapting access to a packet switching network including a dynamic bandwidth adjustment mechanism which continuously monitors the mean bit rate of the signal source and the loss probability of the connection. These values are filtered to remove noise and then used to test whether the values fall within a pre-defined acceptable adaptation region in the mean bit rate, loss probability plane. Values falling outside of this region trigger bandwidth adaptation procedures which, in turn, result in acquiring a new connection bandwidth, and determining new parameters for the adaptation mechanism. Furthermore, the mechanism controls the number of connections that can be adapted by a single processor, given its processing capability. It ensures fairness between the connections in the sense that it prevents a single connection from using, on the average, a greater portion of the processor capacity than it should.

Abstract: Traffic congestion control is provided for a network node multiport switch capable of switching data packets of different priorities from input lines, via receive adapters, to output lines via transmit adapters. A spacing function is performed to limit the rate of data transfers through the switch in the absence of high priority data at the input lines and in the absence of a backpressure signal indicating the switch is congested at its output. If high priority data is detected or a backpressure signal has been generated, the data transfer rate is increased to deal with possible congestion.

Abstract: A method and an apparatus to calculate in an intermediate node of a communication network, the new Frame Check Sequence (FCS) appended to a data bits message which has been modified in said intermediate network node. The invention is useful for high speed networks where the transit delay needs to be optimized in the network along with the computing resources in the intermediate network nodes in terms of computer cycles and memory size. The invention consists in calculating the difference between the FCS using the difference between the modified fields in the message and the distance in bits between the end of the modified field and the end of the message; the calculation consists in differentiating `short messages` in the data flow and to provide an optimized processing for the short messages, the processing for larger messages being based on this first optimized processing.

Abstract: A method dynamically changes the bit rate or bandwidth of constant bit rate data structures in an Asynchronous Transfer Mode (ATM) communications environment. The method defines within a data channel a Change indicator (CI) indicative of an end user's request for a bit rate change within said data structures. The Change Indicator is continuously transmitted from a source side to a destination side in the ATM environment, along with the data structures on said data channel. Upon receipt at the destination side of a user's request of a bit rate change, the destination side modifies the value of said Change Indicator. The source side, acknowledges the modification of the value of the Change Indicator, whereby the transmission of data structures continues on the data channel with a new constant bit rate.

Abstract: This technique for coding images involves filtering the original input image into subband images using successive high-pass and low-pass filterings over a tree-shaped filter with each tree filtering stage involving re-scaling operations adjusted to keep the subband image signal dynamics substantially stable throughout the filtering tree.