Pmc-Sierra, Inc.

Ixia

Veriwave Incorporated

Keysight Technologies Singapore (Holdings) Pte. Ltd.

Keysight Technologies Singapore (Sales) Pte. Ltd.

Keysight Technologies Singapore Pte. Ltd.

Thomas Alexander

Lester Noel Stott

David Jennings Wicker

David Walden Wong

Alexander David Rekow

Bradley H Smith

Jeffrey Dean Marker

L Noel Stott

Vernon Robert Little

Kalyan R Sundhar

Timothy Earl Bennington-Davis

Wayne D Music

Barry Benjamin Hagglund

Eran Karoly

Matt Smith

Jerry Lee Perser, Jr

Calvin S Taylor

Sitarama Penumetsa

Ryan McDonough

James Whitney Kimbrow

Alexander D Rekow

Systems and methods are disclosed herein to provide improved online security testing of security devices and networks, including but not limited to networks containing wireless access points. In accordance with one or more embodiments and aspects thereof, a distributed online test system is disclosed that combines an online test manager with one or more remote probes to generate simulated attacks and verify their effectiveness. Such a system may offer improved capabilities such as the ability to conduct attacks over geographically distributed network topologies, the ability to assess the security functions of wireless networks, and simpler and more cost-effective online security testing.

Distributed online wireless security test system

Systems and methods are disclosed herein to provide improved channel estimation and channel state information (CSI) transfer in a wireless data communication system, including but not limited to Multiple Input Multiple Output (MIMO) communication systems. In accordance with one or more embodiments and aspects thereof, a channel estimation and CSI transfer system is disclosed that extends and utilizes existing frame transfer elements to accomplish estimation and transfer. Such a system may offer improved capabilities such as a lower overhead CSI transfer, reduced data transfer latency, and more frequent CSI measurements.

Systems and methods for channel state information exchange

Systems and methods are disclosed herein to provide improved clock synchronization between wireless data communication transmitters and receivers, including Orthogonal Frequency Division Multiplexing (OFDM) communication systems. In accordance with one or more embodiments, a clock synchronization system is disclosed that includes an adaptive threshold function operative in conjunction with a synchronizer that adjusts the frequency and phase of a receive clock oscillator. Such a synchronization system may offer improved capabilities such as resistance to radio frequency (RF) channel impairments and noise, rejection of mis-decoded clock synchronization signals, and handling of multiple transmitters.

Systems and methods for wireless clock synchronization

Systems and methods are disclosed herein to provide communication test systems for the mobility testing of multi-user multiple-input multiple-output (MU-MIMO) radio frequency wireless data communication devices, systems and networks. In accordance with one or more embodiments, a test system containing an MU-MIMO traffic generator and analyzer is disclosed that includes a mobility effects scheduler operative in conjunction with a channel impairment simulator to perform tests related to mobile MU-MIMO devices such as wireless clients and terminals. Such a test system may offer improved capabilities, such as flexible measurements of mobility performance, more accurate assessments of MU-MIMO wireless channel utilization and data throughput, measurements on MU-MIMO devices under mobility stress, and automated measurements of MU-MIMO mobility testing.

Systems and methods for mobility testing of MU-MIMO

Systems and methods are disclosed herein to provide communication test systems for the testing of packet data communication devices, systems and networks. According to one aspect of the subject matter described herein, a test system containing an integrated traffic, protocol and waveform analyzer is disclosed that includes a traffic generator/analyzer and a protocol engine that triggers a waveform analyzer to analyze the signal waveform of a device under test at a predetermined point. Such a test system may offer improved capabilities such as a more selective and accurate measurement of complex signal waveforms, more automated measurements of waveforms pertaining to wireless communication data streams, and more rapid identification and measurement of waveforms corresponding to errored packets.

Systems and methods for using protocol information to trigger waveform analysis

Systems and methods are disclosed herein to provide improved channel estimation in a wireless data communication system, including but not limited to Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) communication systems. In accordance with one or more embodiments and aspects thereof, a channel estimation system is disclosed that regenerates a representation of the original transmitted signal from the received digital bitstream and selectively applies it to refine and improve channel estimation and signal equalization calculations using the data symbols contained within received frames. Such a system may offer improved capabilities such as more accurate signal reception, reduced bit error ratio, and improved Multi-User MIMO (MU-MIMO) reception.

Systems and methods for improved wireless channel estimation

Systems and methods are disclosed herein to provide improved channel estimation in a wireless data communication system, including but not limited to Multiple Input Multiple Output (MIMO) communication systems. In accordance with one or more embodiments and aspects thereof, a channel estimation system is disclosed that utilizes data payload portions of received wireless packets to calculate estimates of the radio frequency (RF) channel traversed by these packets, and iteratively refines and improves these estimates by selectively utilizing successive received packets according to the application of certain metrics. Such a system may offer improved capabilities such as: more accurate signal reception, reduced bit error ratio, and better reception of short data packets.

Systems and methods are disclosed herein to provide communication test systems for the testing of multiple-input multiple-output (MIMO) radio frequency wireless data communication devices, systems and networks, including Multi-User MIMO (MU-MIMO) devices and systems. In accordance with one or more embodiments, a test system containing an integrated MIMO signal analyzer is disclosed that includes a protocol engine operative in conjunction with a waveform generator and waveform analyzer that analyzes the signal waveform of a device under test. Such a test system may offer improved capabilities such as a simpler and more flexible measurement of complex MIMO signal waveforms, more automated measurements of MIMO waveforms including beamforming functions, and more accurate measurement of the efficiency of MIMO related functions such as channel estimation, transmit precoding and beamforming.

Systems and methods for beamforming measurements

Systems and methods are disclosed herein to provide improved communication system test techniques. For example, in accordance with an embodiment of the present invention, a wireless device test system is disclosed having a channel emulator for multipath and/or MIMO applications to allow the testing of wireless devices (e.g., WLAN devices) in a cabled environment.

Channel impairment emulator systems and methods

Apparatus and methods enabling the efficient and repeatable measurement of mobility performance of wireless data communications equipment are described. This is particularly useful for testing the impact of roaming of Wireless Local Area Network (WLAN) devices, such as clients, between their counterparts, such as access points. The apparatus and methods include controlled emulation of roaming by WLAN devices, using a set of WLAN tester units, by activating and deactivating instances of emulated devices on different tester units to simulate the physical translation of the actual WLAN devices in an environment. Simulation of increasing and decreasing distance during the roaming process is also rendered possible. This enables various mobility performance measurements to be made on WLAN devices in a repeatable manner, free from artifacts due to device manufacturing tolerances.

Method and apparatus for wireless mobility measurements

Systems and methods enabling the efficient and repeatable simulation of mobility, during performance measurements of wireless data communications equipment are described. These are particularly useful for testing the impact on performance of spatial separation between Wireless Local Area Network (WLAN) devices, clients, relative to their counterparts, access points. In accordance with one or more embodiments of the present invention, the controlled emulation of spatial distance effects by injecting impairments into the transmitted and received wireless data packet streams are disclosed to simulate the impact of distance on properties of signal level, signal to noise ratio, and frame error ratio. Injection of impairments may be accomplished by varying the transmit power, artificially inducing errors into transmitted frames, and withholding acknowledgements for otherwise valid received frames, at levels consonant with the amount of distance to be emulated. This enables various mobility performance measurements to be made on WLAN devices without actually requiring that they be physically separated.

Method and apparatus for controllable simulation of mobility

Systems and methods are disclosed herein to provide communication testing for wireless or wired packet data communication devices, systems, and networks. In accordance with one embodiment of the present invention, a test system containing a multilevel scheduler is disclosed that includes cascaded schedulers, a software interface, and specific media protocol feedback to accurately emulate multiple clients on a network, with possibly numerous traffic flows per client. Such a test system may offer capabilities such as a more accurate emulation of client contention and collisions, a more accurate emulation of bandwidth sharing between clients, and a more accurate emulation of traffic flow multiplexing between flows.

Communications test system with multilevel scheduler

Apparatus and methods facilitating a distributed approach to performance and functionality testing of location-sensitive wireless data communication systems and equipment are described. A plurality of test units, geographically distributed at arbitrary points in a three-dimensional volume surround the system or equipment under test. Each test unit generates test stimuli and records responses from the device under test, and emulates the effects of changes in spatial location within an actual wireless network environment. A central controller co-ordinates the set of test units to ensure that they act as a logical whole, and enables testing to be performed in a repeatable manner in spite of the variations introduced by the location sensitive characteristics of wireless data communication networks. The central controller also maintains a user interface that provides a unified view of the complete test system, and a unified view of the behavior of the system or equipment under test. For diagnostic purposes, the recorded responses may be regenerated to view any defects as many times as necessary to correct them. Alternatively, each test unit may have either wired network interface units, instead of a wireless interface unit to test systems or equipment forming part of a wired network portion in the wireless data communication system.

Location-based testing for wireless data communication networks

Apparatus and methods facilitating a distributed approach to measuring the RF propagation characteristics of an indoor area or region are described. Such measurements are particularly useful during the installation and management of indoor wireless data communication networks, such as Wireless Local Area Networks (WLANs). A plurality of sounder units may be geographically distributed at arbitrary points in a two-dimensional area surrounding the indoor area or region whose RF propagation characteristics are to be measured. These sounder units are linked to a central controller, which functions to control all of the sounder units as well as to maintain a user interface that provides a user with a display of the measured propagation characteristics of the region. Each sounder unit is capable of independently injecting RF stimulus signals with some desired radiation pattern into the region being measured, as well as recording received signals from which the RF propagation characteristics may be calculated. The central controller co-ordinates the set of sounder units to ensure that they act as a logical whole, and also enables propagation measurements to be made over long periods of time in order to capture time-varying characteristics of the indoor environment.

Method and apparatus for multi-dimensional channel sounding and radio frequency propagation measurements

The present invention is a SONET payload processing system capable of handling virtual concatenation of SONET payloads. The payload processing system enables combinations of sub-frames, comprising an arbitrary number of virtual concatenation data streams, to be multiplexed into a single SONET frame stream. The present invention further provides a processing system that is not limited by the number of sub-frames or the grouping arrangement. The payload processing system accepts both virtual concatenation and contiguous concatenation within the same SONET frame stream and processes them into blocks of data that do not intermix information from different channels.

Growing community of inventors

Mulino, OR, United States of America

Thomas Alexander