Azimuth Systems, Inc.

Other

Azimuth Networks, Inc.

Charles R Wright

Fanny Mlinarsky

John Robert Griesing

John Ernest Ziegler

A heterogeneous network scenario is simulated using a combination of real cells, real user devices, and a multi-cell network emulator which provides emulated cells, emulated real devices, and channel emulation. The multi-cell network emulator may utilize playback files and signals from the real cells and real user devices to generate emulated cell signals and emulated real device signals. Further, a single real signal can be utilized to generate multiple emulated signals.

Small cell interference emulator

Improved performance testing of a wireless device is disclosed. The system is particularly suited to testing devices having multiple antennas. The device under test (DUT) is placed in a reverberation chamber with antennas for transmission of a test signal to the DUT. The number of antennas deployed in the reverberation chamber and placement of those antennas is selected such that no line-of-sight transmission component exists from test system antenna to DUT antenna, and the number of antennas deployed in the reverberation chamber is greater than the spatial rank of the signal. The antennas are driven by a programmable channel emulator capable of generating fading, correlation, delay, Doppler and other channel condition phenomena. Furthermore, the antennas are driven individually by a plurality of independent fading processes. The combination of the programmable channel emulator and reverberation chamber creates a multipath environment which simulates signals arriving from different locations, with different delays, as well as the simulation of device motion. The system also includes instruments to produce test signals and to measure the performance of the DUT.

Testing performance of a wireless device

Test equipment operable to evaluate handoff in wireless networks can be configured as an infrastructure test system or a client mobility test system. The infrastructure test system includes a plurality of client emulating devices and a client motion emulator for testing real access points. Each client emulating device is operable to emulate multiple individual virtual mobile devices ('virtual mobile devices'). The client motion emulator computes a mathematical representation of the modeled network and motion of virtual mobile devices in that network. The client motion emulator employs the mathematical representation to calculate path loss between virtual mobile devices and the real access points in the modeled network. The calculated path loss information is transmitted to the virtual mobile devices. Path loss of communications from a virtual mobile device to an access point is implemented via a programmable attenuator.

Evaluation of handoff in wireless networks using emulation

A modular test chassis for use in testing wireless devices includes a backplane and a channel emulation module coupled to the backplane. The channel emulation module comprises circuitry for emulating the effects of a dynamic physical environment (including air, interfering signals, interfering structures, movement, etc.) on signals in the transmission channel shared by the first and second device. Different channel emulation modules may be included in the test system depending upon the protocol, network topology or capability under test. A test module may be provided to generate traffic at multiple interfaces of SISO or MIMO DUTs to enable thorough testing of device and system behavior in the presence of emulated network traffic and fault conditions. A latency measurement system and method applies timestamps frames as they are transmit and received at the test module for improved latency measurement accuracy.

Latency measurement apparatus and method

Modular wireless test architecture and method

A method and system for simulating a wireless environment is provided including a central RF combining component; a plurality of connection nodes, each connection node in RF connection with the central RF combining component through a programmable attenuation component; wherein the programmable attenuation components are controlled by a controller console, the controller console maintaining information regarding simulated spatial positioning of the plurality of connection nodes in the simulated wireless environment, and adjusting the programmable attenuation components to appropriately simulate the simulated spatial positioning of the connection nodes in the simulated wireless environment. Additionally, an RF module for creating and receiving RF signals in a test environment is provided.

Test system for simulating a wireless environment and method of using same

The present invention discloses catheter tube retaining devices having a disk rotatably coupled to the base, and a strap (or equivalent) for attaching such a device to the human body. The disk is capable of rotation relative to the base through at least a 90 degree arc. Further, the disk has formed upon a top surface at least one U-shaped retaining channel or groove of sufficient diameter as to retain a catheter tube in interference fit, without restricting the passage of fluid through such tube. Preferably, at least one pair of opposing tabs (or equivalent) protrude over the retaining channel to assist in the retention of the catheter tube. The disk can accommodate four channels, for different sizes of catheter tubes.

Growing community of inventors

Winchester, MA, United States of America

Charles R Wright