Abstract: A system and method for providing an apparent echo return loss is provided. A communications network may include a gateway coupled to a local exchange network. The gateway may receive signals from a packet network and output signals to a circuit switched network, which may output return signals to the gateway. The local exchange network may provide an echo return loss on signals received from the gateway. The gateway may also provide an initial echo return loss to signals prior to sending the signals to the network. The echo return loss provided by both the gateway and the local exchange network may enable the gateway to determine when to trigger adaptation in order to provide estimates of echo signals generated by the network, and to subsequently eliminate these echo signals from the return signals.

Abstract: A multi-port network communication device includes a plurality of ports for the reception and transmission of addressed data packets which include media access control address data, a forwarding mechanism for directing packets received at any of said plurality of ports to at least one of the plurality of ports, a memory for the selectively controllable storage of permitted media access control addresses, and means for restricting forwarding of packets from the device in response to an examination of media access control data in said packets and said permitted media access control addresses. The forwarding of a unicast packet having a source address and a destination address is prevented when neither of those addresses in the unicast packet corresponds to a permitted media access control address. The forwarding mechanism prevents the forwarding of multicast or broadcast packets to ports which are not connected to devices having permitted media access control addresses.

Abstract: The present invention relates to the field of data communication electronics and to a wired or wireless signal transmitter or receiver and methods providing improved signal-to-noise ratio (SNR) performance for the reception of data packets transmitted in the form of symbols modulated onto a signal. More particularly, apparatus and methods are disclosed for detecting the preamble and symbol boundaries of received data packets encoded with OFDM and other multi-carrier symbol transmission systems. Also disclosed are combinations of sensitive preamble detection and data payload and/or signal field encoding methods to spread data redundantly, to improve reception under a low SNR condition.

Abstract: In one embodiment, the present invention is a computer implemented method for assigning a back-off interval to an intermediary network access device in a Carrier Sense Multiple Access (CSMA) network. The number of client devices concurrently attempting to access said network via said intermediary network access device is first determined. The back-off interval is then determined based upon the number of client devices concurrently attempting to access the network via the intermediary network access device and is assigned to the intermediary network access device.

Abstract: A method for determining symbol boundaries in an ADSL modem, comprising receiving multi-frequency modulated signals in the time domain, wherein the multi-frequency modulated signals include a pilot signal at a pilot frequency. Performing a time-to-frequency transform on the multi-frequency modulated signals to recover the pilot signal. Iteratively computing a phase error for the pilot signal over a number of transform regions. Selecting the transform region with the lowest phase error.

Abstract: A network unit comprises a multiplicity of ports for transmitting and receiving data packets, a bridging facility and a routing facility. The network unit has a multiplicity of mutually exclusive states which includes an initial state from which said network unit can transition to either a slave state; or a waiting state from which in the absence of receipt from elsewhere of a broadcast advertisement including an advertised address corresponding to an address of the unit, the unit transitions to a master routing state in which the routing facility is enabled and the unit broadcasts a corresponding advertisement including an address of the unit. The unit transitions from the waiting state, when it receives from elsewhere (i.e., another unit) such a broadcast advertisement, to a master bridging state in which the routing facility is disabled and the unit provides commands for disabling a routing facility of other similar units to which the network is connected.

Abstract: The present invention includes methods and devices to compensate for gain and phase imbalance for OFDM and other multi-carrier symbol transmission systems. More particularly, methods and devices for determining compensation parameters are provided. This invention may be applied to a variety of standards utilizing OFDM technology, including IEEE 802.11a, Hiperlan/2 and MMAC. Further description of the invention and its embodiments are found in the figures, specification and claims that follow.

Abstract: A dynamic network address registration system and method. In one embodiment, the present invention is comprised of a first device which is adapted to communicate over a communications network. The present invention is a also comprised of a second device which is adapted to communicate via a communications network, and, more specifically, is adapted to communicate with the first device via the communications network. The present invention is further comprised of a controller which is adapted to be coupled to the communications network. The controller of the present invention is adapted to store address information for the first device, and to store address information for the second device therein. The controller is further adapted to provide the address information of the second device to the first device such that a communication path can be efficiently established between the first device and the second device via the communications network.

Abstract: Methods and a device for changing the message size broadcast over a network and furthermore preventing fragmentation in networks are provided. The device intercepts a message transported across a network, wherein the message is sent from a data source to a data receiver and changes the message size. In addition, the device may use the methods to change the message size of data transmitted over a network thus reducing fragmentation. As a result, network devices such as classifiers preferably avoid re-assembling fragments. More specifically by reducing re-assembling, network devices like a classifier can react more quickly to applications requiring information found in both of an IP and TCP/UDP header.

Abstract: A method and apparatus implementing the method, of selecting a bit load b for a channel in a carrier system. The carrier system encodes data based on a constellation of points. Each point represents a tuple of data. The constellation has a self-similarity property. The bit load for the channel is selected based on the self-similarity property of the constellation. In an alternate embodiment, the method and apparatus are used to determine the bit load of the sub-channels in a multi-carrier system.

Abstract: An electronic communication network includes a connectivity plane and a control plane. The control plane includes at least one control node for inspecting packets received by the control plane. The control plane is configured to perform network traffic control functions on the packets received by the at least one control node before transmitting the packets to any other node in the network. The network traffic control functions include one or more of access control, attack control, and application control.

Abstract: A method of diagnosing, in a network comprising two devices (A), (B) connectable by a link (20), which link may be a physical link such as a cable or may be a wireless link, the type of failure of the connection between the devices (referred to as “link failure”, although the failure may only be a partial failure such as lack of synchronization and may lie not in the link itself but in the one or both devices or the protocol used), said method comprising connecting the two devices together (for example, by physically connecting them or switching on the link between them), at least one (B) of the devices including a plurality of registers (23), each register being adapted to store data about one or more types of said failure, running an auto-negotiation sequence, detecting said failure and passing signals relating to that failure to the relevant register(s), interrogating the or each register, and determining the type of said failure.

Abstract: The present invention relates to multiple antenna wireless access points that multiplex signals by spatial division. In particular, it relates to grouping clients of the access point for spatial division multiplexing. Particular aspects of the present invention are described in the claims, specification and drawings.

Abstract: A system and methods are shown for providing Internet Protocol communication services to a mobile client. One method includes sending a registration request from a radio node to a control node responsive to detecting a mobile client in a service area of the radio node. When the control node receives the request from the radio node, the control node determines a foreign agent to provide communication services to the mobile client. In one embodiment, the control node determines the foreign agent based on a mobile client information record, a radio node record, and a plurality of foreign agent records associated with the radio node. In one embodiment, the control node may select a last serving foreign agent associated with the mobile client.

Abstract: An interface between a wireless node and a network node includes an encapsulator for temporarily converting data frames into Ethernet frames for the link between the two nodes and de-encapsulating the Ethernet frames before the data is processed at the network node.

Abstract: A method for switching between an individual computer's network interface technologies without interrupting any pending data transmissions on the existing network connection. The method include detecting when an existing network connection is no longer connected and if there are any available network connections on different network interface technologies. In addition, the method determines the address of the new connection and reassociates all existing data flow with the new network connection. Data is then routed to the new network connection whether it is on the same subnet or a different subnet.

Abstract: A buffer ring is utilized to track and control the distribution of information. Index variables that refer to storage locations or slots in the buffer ring are utilized to track the receipt and distribution of information. The variables initially point to the same slot. As information is received a status indicator associated the slot is checked and if the location is free either the product information elements or addresses of where the product information are entered in the slots. They are tracked by a producer variable that is incremented to indicate the next available slot. Slots between the consumer variable and the producer variable define a segment of the buffer associated with a particular thread. The information is forwarded to a thread based upon the variables. As product information elements are forwarded control of the buffer ring is obtained and the variables determine a buffer segment that is forwarded.

Abstract: A system and method for feature-based service control using Session Initiation Protocol (SIP) in an Internet Protocol Automatic Branch Exchanges (IPABX) system is described. The system and method include a new Event package and new Enhanced SIP methodsto control information for various feature-based services like wakeup alarm, call forwarding, voicemail configuration, and other services provided by traditional PBX systems. A user provides input to a client device to activate or deactivate feature-based services. In response, the client device sends a message to the IPABX server to activate or deactivate the feature-based service(s). The IPABX server then notifies the client device that the feature based-service(s) have been activated or deactivated.

Abstract: A system and method classifies packets with a programmably fixed network processor program and dynamically updated data structures. The network processor program selects predetermined packet field values of the packets transmitted across the network and classifies the packets by matching one or more packet field values with a data structure. New packet classifications are dynamically created by updating the data structure to associate one or more predetermined packet field values with the new packet classification. For instance, a parse tree program extracts packet header information and matches the packet header information to the data structure. A pattern tree data structure provides longest prefix matches and an ordered tree data structure provides combination matches so that classification of arbitrary Boolean combinations of extracted header fields can be formed.

Abstract: A connecting unit for use in a system comprising a ‘stack’ of network communication units having a cascade connection has three ports having lines for forwarding and receiving data packets and for forwarding and receiving control messages. The connecting unit increments a first signal value defining an identification number received by way of a control message at a first port, provides the received signal value by way of a control message to the third port and provides the incremented signal value by way of a control message to the second port. The connecting unit also receives a second signal value defining an active unit count by way of a control message at the first port and provides the second signal value, incremented or not in dependence on a control message received at the third port, in a control message at the second port.