USRobotics

About: USRobotics is a based out in . It is known for research contribution in the topics: Data compression & Signal. The organization has 63 authors who have published 53 publications receiving 2617 citations. The organization is also known as: U.S. Robotics & US Robotics.

Systems for connection of physical/electrical media connectors to computer communications cards

Abstract: A communications card capable of being mounted in electrical communications with a computer has formed therethrough an aperture so sized and shaped as to be capable of receiving a physical/electrical media connector. The media connector has a biased retention clip, a contact pin block, and contact pins. The retention clip has several standardized characteristics including a broad fixed end protruding from an outer surface of the contact pin block. The broad fixed end tapers abruptly at a transition notch down to a narrow free end, capable of being manipulated by a user to remove the physical/electrical media connector from the aperture in the communications card. In use, a media connector is inserted directly into the aperture in the communications card, the aperture being in contact with a plurality of contact wires fixed within the communications card. The communications card is divided into a retractable access portion of the communications card which can be directly accessed by manipulating an actuating mechanism releasing a retention means thereby allowing a spring to push the retractable access portion of the card outside of the computer housing. The retractable access portion of the communications card may be reinserted back into the computer housing to be carried internally when not in use.

Distributed processing ethernet switch with adaptive cut-through switching

Abstract: A packet switching system includes at least two network cards each receiving data packets via a plurality of associated ports, a system card, and an interconnect for connecting the system card to the network cards. Each one of the network cards comprises a plurality of port controllers for sending and receiving packets to and from a corresponding port and a packet processor for buffering packets received by the port controllers. The packet processor then sends destination addresses to the system card via the interconnect and receives forwarding information from the system card. The processor then forwards the packet in response to the forwarding information. The processor begins forwarding the packet in response to the forwarding information before the packet has been entirely received and checks the integrity of the packet by reference to check sum information contained in the packet as in cut-through switching. Future packets from the source port have their validity checked prior to forwarding in response to receiving an invalid packet from the source port as in store and forward switching.

Telephone call routing and switching techniques for data communications

Abstract: A method of processing incoming digital telephone calls from remotely located call originators which are destined for receipt by a host computer system. The host computer system is linked to the telephone network by a network access server. The call originators may be any type of data terminal, such as a personal computer or a credit card swipe, which is connected to a modem. The network access server extracts control signals imparted onto the telephone line and correlates the control signals with particular communications, routing or applications protocols identified with the call originators. The modem in the network access server which answers the call is configured during the call connect process and placed in a compatible format for the communications protocol of the incoming call. This dynamic custom configuration of the modem reduces the overall telephone call connection and processing time. The control signals may also be used by network access server for customized call routing or by the network access server or host computer system to run specialized application programs. The method is particularly suitable for use by large enterprises handling a high volume of incoming calls in which data is transmitted to the host computer system according to a variety of different communications protocols, or where the implementation of different routing paths or applications programs is desireable according to the identity or classification of the call originator.

Transparent support of protocol and data compression features for data communication

Abstract: A proxy engine (50) enables network protocols that are supported by both network endpoint application (30) and local endpoint application (20). The proxy engine (50) determines network control protocols and enables data compression techniques (54) that are supported by the network endpoint application (20) and the proxy engine. It transmits data between the local endpoint application (20) and the network endpoint application (30). The proxy engine (50) also opens multiple communication channels for transmitting data simultaneously between the local endpoint application and the network endpoint application.

Compensation method for I/Q channel imbalance errors

Abstract: A method in which correctable I/Q imbalance errors in a complex receiver can be detected and compensated for digitally without the use of special calibration signals. Differential D.C. offset errors are compensated by averaging the incoming I d and Q d digital signals and subtracting from them an expected value of differential D.C. offset, for example, computed from the long term average of the I and Q signals to create I' and Q' signals. Differential gain imbalance errors are corrected by calculating a root means square average of the I' and Q' digital signals and applies to them compensation coefficients K x and K y determined from either the RMS average or from a Stochastic Gradient Algorithm. The DSP compensates for the quadrature phase errors by calculating a compensation matrix which is independent of the frequency of the carrier and applies the compensation matrix to the I' and Q' digital signals. The compensation matrix for quadrature phase errors is completely independent of the frequency of the input carrier signal supplied to the complex receiver, and is not dependent on the use of a calibration signal. The compensation may be performed as a step in calibration of the complex receiver, or continuously.