Abstract: A refetch logic propagates data from a first source to a link controller by default. The link controller prefetches data from the refetch logic to generate a first packet prior to receiving control of the transmission medium on which the data is to be transmitted. The refetch logic changes sources and propagates to the link controller data from a second source if necessary. At the same time, the refetch logic also causes the link controller to discard the first packet and generate a second packet from data provided by the second source.

Abstract: The method described here provides for high-speed, Quality of Service (QoS) driven, and secure transport of voice, video and data packets for facilitating the convergence of multiple networking facilities into one. The method involves replacing one or more bits in the IP header address fields and replacing them with or adding to them unique virtual connection or virtual circuit (VC) identifiers for node-to-node, that is device-to-device, connectivity as well as for representing values or parameters for packet type, QoS, security, network management and node/link resources. Identifiers for the above parameters are developed and saved at each node as a switching table. The values representing the identifiers from a switching table are used to assign virtual connections as well as control the flows of packets.

Abstract: A method for operation of a distributed computer system (SYS) comprising network nodes (NKN, NK1–NK6), each of which has at least one node controller (STR, ST1–ST6) and one communication controller (KK1–KK6), the communication controllers (KKK, KK1–KK6) being connected to each other via at least one communication channel (BUS), and provision being made between the communication controller (KK1–KK6) and the node controller (STR, ST1–ST6) of a network node (NKN, NK1–NK6) for a fault tolerance layer (FTS, FT1–FT6) that is set up to receive messages exchanged between the network nodes (NKN, NK1–NK6), the fault tolerance layer (FTS, FT1–FT6) deciding, based on information received pertaining to the status of at least one network node(NKN, NK1–NK6), about the functioning of the at least one network node (NK1–NK6) via a coordination procedure, and the coordination result being made available as an output signal (ASS, AS1–AS6), the at least one network node (NKN, NK1–NK6) being triggered as a function of the output s

Abstract: A PBX system using an unmodified personal computer as the host server and using expansion slots to couple one or more switch cards to the system bus, and, optionally including a network interface card to couple the PBX system to other client computers running telephony enabled applications to control the PBX via a local area network. The switch card(s) are each coupled to a chain of one or more port expansion units that do not consume expansion slots. Each PEU contains a DSP and a microcontroller, an FPGA and port interface circuitry to interface to POTS CO lines, extension telephone lines, T1 lines or PRI lines. The personal computer is programmed with a PBX process that controls operations of the overall system and may also be programmed with conventional voice mail applications or integrated voice response and other applications to implement various telephony functions such as recording voice mail or prompt callers to input DTMF tones indicating what they want to do.

Abstract: A switch fabric for routing data has a switching stage configured between an input stage and an output stage. The input stage forwards the received data to the switching stage, which routes the data to the output stage, which transmits the data towards destinations. Each input device of the input stage transmits bids to the crossbar devices of the switching stage to request connections through the switching stage for routing the data to the output devices of the output stage. In one aspect, each crossbar device has (1) a bid arbitrator that determines whether to accept or reject each received bid, wherein, in response to a collision between multiple bids, the bid arbitrator accepts two or more of the colliding bids in a single time slot; and (2) memory for storing one or more accepted cells for the same output device, wherein the crossbar device can transmit grant signals for two or more accepted bids for the same output device in a single time slot.

Abstract: A communication connection to a second user equipment (UE B) by a first user equipment (UE A) is requested, the request including a specific information element for an identification of UE B, a determination is made (S3) in a database on the basis of the specific information element identifying UE B's location within the communication network, a decision is made (S5, S6) whether UE B is reachable or accepts the communication connection or not, and if the decision is positive, the communication connection is established (S7) between UE A and UE B adapted to perform a packet data communication.

Abstract: The present invention provides a network device that fully utilizes the available space in a standard telco rack through the use of multiple mid-planes. Full utilization of available space allows a high switching capacity network device including both physical layer switch/router subsystems and upper layer switch/router subsystems to be fit in one telco rack. Inter-mid-plane connections may be provided by connecting switch fabric cards and/or control processor cards to each of the mid-planes. Providing a multi-layer network device in one telco rack allows for intelligent layer 1 switching (for example, dynamic network connection set up), allows for one network management system to control both layer 1 and upper layer networks and eliminates grooming fees.

Abstract: A method for synchronizing a timing device of a client station via a communications network is disclosed. A plurality of packets is sent from a time server to the client station via the communications network. Upon receipt of the plurality of packets at the client station a time indicative of a local time of receipt of the plurality of packets is determined and the plurality of packets are returned to the time server via the communications network. Upon receipt of the plurality of packets at the time server data in dependence upon round trip delay of the packets and variance in packet spacing are determined and compared to threshold values. If the determined data are within the threshold values data indicative of a time correction are determined and sent from the time server to the client station.

Abstract: Disclosed is an architecture for a network access server wherein a switching device is placed between a network gateway device and a first network, where the switching device detects the presence or absence of a security protocol field in the header information of data packets received from the first network and routes the data packets accordingly. When the security protocol field is absent, the switching device routes the data packet to the network gateway device for processing in accordance with a protocol service provided by the network access server. When the security protocol field is present, the switching device decrypts the data packet, processes the data packet in accordance with the protocol service provided by the network access server, and routes the data packet to another device within the network access server on the basis of decrypted address information within the data packet.

Abstract: A transport interface for time division frames, in particular SDH frames transmitted between telecommunications network nodes according to a specified transport protocol, said nodes comprising first circuit means (SM) for processing said time division frames (TRM, TRM2) according to said specified transport protocol, and second circuit means (FP) apt to exchange second information streams (FDS) with said first circuit means (SM) through said transport interface (STI). According to the invention, said second information streams (FDS), exchanged by the transport interface (STI) with the first circuit means (SM) and with the second circuit means (FP), are simplified with respect to said time division frames (TRM1, TRM2) received from said node, in particular are composed by a data stream (BD, T_BD, R_BD) sent in a co-directional way and by an address information (EAR, T_EAR, R_EAR) sent by the transport interface (STI).

Abstract: A WAP (Wireless Application Protocol) analyzer located on a transmission line between communication apparatuses using WAP. A WAP packet includes at least one WTP-PDU (Wireless Transaction Protocol—Protocol Data Unit). The WAP analyzer comprising, database (16) for storing state-transition specification data that define a state-transition with a cause-and-effect relationship between WTP-PDUs, states of a WTP layer, primitives between the WTP layer and WSP (Wireless Session Protocol) layer, and states of the WSP layer, based on WAP specification, means (11) for extracting the WTP-PDUs from the WAP packets, and means (13) for estimating the state-transition of the WTP layer and the WSP layer, to the apparatus that received one of the WTP-PDUs and subsequently sent other of the WTP-PDUs, for each pair of a sender and a receiver.

Abstract: The present invention relates to a computer network and a method for using the network The network and method employ powered multiplexing connection devices which electronically couple two or more network devices to the network. The signals from the network devices to the network are multiplexed at the powered multiplexing connection devices and the signals from the network to the network devices are demultiplexed at the powered multiplexing connection devices. The multiplexing enables the various work-center devices to communicate with the network and, in some cases, to receive power over the network connection. The intelligent electronic circuitry is also capable of aiding in network security and management and in monitoring the status of the network infrastructure.

Abstract: The present invention focuses on the aggregation of flows belonging to different classes of non-guaranteed-delay traffic into a single FIFO queue in a downstream stage of the multi-stage switch. These include the guaranteed flows requiring bandwidth reservation, the best-effort flows that require a fair share of the excess bandwidth, and the flows that require both types of guarantee. We disclose a credit-based backpressure scheme which selectively controls the traffic originating from the previous stage of the system while achieving the goal of meeting the requirements of the individual flows. The credit function is maintained for each controlled traffic component in the aggregate session, and its objective is to balance the actual arrival rate of the component with the service rate dynamically granted by the downstream scheduler. The number of flows that can be aggregated is related to the complexity of maintaining the credit functions for the different traffic components.

Abstract: A method of handling data packets in a network switch is disclosed. The method includes placing incoming packets into an input queue and applying the input data packets to an address resolution logic engine. A lookup is performed to determine whether certain packet fields are stored in a lookup table; and the result of the lookup is also examined to determine if it provides a trunk group ID for a particular data packet of the input data packets. When the lookup provides a trunk group ID, the trunk group ID is used to determine an egress port and the particular data packet is forwarded to the egress port. Alternatively, the packet is discarded, forwarded, or modified based upon the result of the lookup, where the lookup does not provide a trunk group ID. A network switch using the method is also disclosed and methods directed to mirroring of data packets are also disclosed.

Abstract: A method for control of packet data transmissions in a TDMA wireless network to provide for additional choices in the allocation of communication channels. Measurement and recovery periods are re-assigned to avoid conflicts in operating conditions. The re-assignments for the GPRS system may be reduced to a simple formula.

Abstract: Method and apparatus for queuing packets are disclosed. In one aspect, a method may comprise assigning each packet a first value; dynamically assigning each packet a second value; and queuing each packet for transmission using the first and second values.

Abstract: Techniques to determine the rate for a data transmission in an OFDM system. The maximum data rate that may be reliably transmitted over a given multipath (non-flat) channel by the OFDM system is determined based on a metric for an equivalent (flat) channel. For the given multipath channel and a particular rate (which may be indicative of a particular data rate, modulation scheme, and coding rate), the metric is initially derived from an equivalent data rate and the particular modulation scheme. A threshold SNR needed to reliably transmit the particular data rate using the particular modulation scheme and coding rate is then determined. The particular rate is deemed as being supported by the multipath channel if the metric is greater than or equal to the threshold SNR. Incremental transmission is used to account for errors in the determined data rate.

Abstract: For exact level balancing or signal-to-noise ratio balancing of received signals in a wave-length-division multiplex transmission system, the associated transmitted signal power levels are adjusted. If the maximum permissible dynamic range is exceeded, the individual transmitted signal power levels are compressed, while the total transmitted signal power level is kept at least approximately constant.

Abstract: In a frequency division multiplexed (FDM) telecommunications system, data is encoded on carriers stepped in frequency within each of a sequence of symbols. The carriers may be arranged in groups between which there are frequency bands in which interference may be expected. The symbols are of predetermined length and are transmitted at a predetermined frequency, and synchronisation to the symbols is needed at a receiver in order to decode the received symbols. During a synchronisation time, a sequence of synchronisation symbols carrying predetermined data is transmitted. The receiver performs unsynchronised Fast Fourier Transforms (FFTs) on the received symbols, starting successive FFTs at about the predetermined symbol frequency. The output of each FFT is evaluated by removing the predetermined data coding from the detected carriers and summing the detected phase differences between the carriers.

Abstract: Techniques to schedule terminals for data transmission on the downlink and/or uplink in a MIMO-OFDM system based on the spatial and/or frequency “signatures” of the terminals. A scheduler forms one or more sets of terminals for possible (downlink or uplink) data transmission for each of a number of frequency bands. One or more sub-hypotheses may further be formed for each hypothesis, with each sub-hypothesis corresponding to (1) specific assignments of transmit antennas to the terminal(s) in the hypothesis (for the downlink) or (2) a specific order for processing the uplink data transmissions from the terminal(s) (for the uplink). The performance of each sub-hypothesis is then evaluated (e.g., based on one or more performance metrics). One sub-hypothesis is then selected for each frequency band based on the evaluated performance, and the one or more terminals in each selected sub-hypothesis are then scheduled for data transmission on the corresponding frequency band.