Abstract: 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.

Abstract: Small anechoic chambers for evaluating a wireless device under test (DUT) are characterized by a set of antennas to which a test signal is applied and for which excitation coefficients are applied such that the test signal approximates a single plane wave or a preselected superposition of plane waves in the near field of the antennas. The test-equipment antennas in the chamber may be as close as one wavelength from the boundary of a test zone in which the DUT is disposed. Hence, the test zone can be in the near field of the test-equipment antennas and the test zone can be less than a wavelength from the chamber walls. Consequently, it is possible to perform tests in a small anechoic chamber that previously required a large anechoic chamber, e.g., advanced spatial channel-model tests and antenna-pattern measurements.

Abstract: Small anechoic chambers for evaluating a wireless device under test (DUT) are characterized by a set of antennas to which a test signal is applied and for which excitation coefficients are applied such that the test signal approximates a single plane wave or a preselected superposition of plane waves in the near field of the antennas. The test-equipment antennas in the chamber may be as close as one wavelength from the boundary of a test zone in which the DUT is disposed. Hence, the test zone can be in the near field of the test-equipment antennas and the test zone can be less than a wavelength from the chamber walls. Consequently, it is possible to perform tests in a small anechoic chamber that previously required a large anechoic chamber, e.g., advanced spatial channel-model tests and antenna-pattern measurements.

Abstract: A wireless network emulation system undersamples log files when the conditions represented in the log files would require a faster refresh rate than the channel emulator can provide. A representative sample may be selected based on number of channel taps, delay spread, maximum value, or being first, last or otherwise identifiable within a group. The RF information from the selected sample is utilized as being representative of a group of related samples for a given time period corresponding to the refresh rate of the channel emulator.

Abstract: Missing or unwanted parameter data indicative of wireless network conditions in a log file or playback file is replaced with substitute parameter data. The substitute parameter data can be calculated based on other data in the log file or playback file, selected from pre-defined data in storage, and provided by a user. The substitute parameter data may also be customized by the user via an interface.

Abstract: One or more events recorded in one or more log files are recognized and processed by performing one or more operations including segmentation, modification, extraction, addition, and subtraction. The processed events are used to generate a playback file which is used by a channel emulator to perform testing.

Abstract: Small anechoic chambers for evaluating a wireless device under test (DUT) are characterized by a set of antennas to which a test signal is applied and for which excitation coefficients are applied such that the test signal approximates a single plane wave or a preselected superposition of plane waves in the near field of the antennas. The test-equipment antennas in the chamber may be as close as one wavelength from the boundary of a test zone in which the DUT is disposed. Hence, the test zone can be in the near field of the test-equipment antennas and the test zone can be less than a wavelength from the chamber walls. Consequently, it is possible to perform tests in a small anechoic chamber that previously required a large anechoic chamber, e.g., advanced spatial channel-model tests and antenna-pattern measurements.

Abstract: A simulator for testing a wireless device includes at least one module capable of being connected with other modules. Each simulator module includes first and second sets of ports, combiners and a channel emulator. Each combiner provides a low insertion loss pathway between a common port and first and second ports of the combiner, and isolation between the first port and the second port of the combiner. The combiners allow interconnection of multiple modules, thereby scaling the number of devices that can be tested by the simulator at a given time.

Abstract: A plurality of wireless devices which communicate with at least one other device are simultaneously tested using a test regime which includes a plurality of tasks. At least one device synchronizes commencement of each task by all wireless devices. At least one device logs performance measurements of each wireless device for each task. Because the wireless devices begin each task at the same time the resulting log files facilitate per-task performance analysis for each wireless device.

Abstract: A plurality of wireless devices which communicate with at least one other device are simultaneously tested using a test regime which includes a plurality of corresponding comparative tasks. Commencement of each task by all wireless devices is synchronized. Test results are analyzed and a side-by-side comparison is provided on an overall, per task type, and per task basis.

Abstract: 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.

Abstract: An over-the-air test system for wireless devices uses log files to simulate realistic time-varying channel conditions and provides channel state information to enable dynamic adaptation to current channel conditions. A signal transmission device transmits test signals to the device under test via a channel emulator. The channel emulator causes the test signals to exhibit channel conditions which vary over time. An over-the-air test chamber in which the device under test is disposed includes multiple antennas which are driven with the test signals from the channel emulator. Channel state information is sent from the device under test to the signal transmission device. The signal transmission device responds to the channel state information by adapting to current channel conditions.

Abstract: 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.

Abstract: A wireless network emulation system undersamples log files when the conditions represented in the log files would require a faster refresh rate than the channel emulator can provide. A representative sample may be selected based on number of channel taps, delay spread, maximum value, or being first, last or otherwise identifiable within a group. The RF information from the selected sample is utilized as being representative of a group of related samples for a given time period corresponding to the refresh rate of the channel emulator.

Abstract: Missing or unwanted parameter data indicative of wireless network conditions in a log file or playback file is replaced with substitute parameter data. The substitute parameter data can be calculated based on other data in the log file or playback file, selected from pre-defined data in storage, and provided by a user. The substitute parameter data may also be customized by the user via an interface.

Abstract: A simulator for testing a wireless device is configured by using an indication of connected devices and channel model to be applied to an identified link received as input to calculate settings for function elements which modify signals to implement simulated effects defined by the channel model. The calculations are performed while a test is running, thereby avoiding delays associated with playback tests. Allocation of simulator paths and function elements are automated, and an indication of how the wireless devices are to be connected to the simulator is provided to the user.

Abstract: Small anechoic chambers for evaluating a wireless device under test (DUT) are characterized by a set of antennas to which a test signal is applied and for which excitation coefficients are applied such that the test signal approximates a single plane wave or a preselected superposition of plane waves in the near field of the antennas. The test-equipment antennas in the chamber may be as close as one wavelength from the boundary of a test zone in which the DUT is disposed. Hence, the test zone can be in the near field of the test-equipment antennas and the test zone can be less than a wavelength from the chamber walls. Consequently, it is possible to perform tests in a small anechoic chamber that previously required a large anechoic chamber, e.g., advanced spatial channel-model tests and antenna-pattern measurements.

Abstract: Time-varying conditions in a wireless network are simulated using an architecture that includes an enclosure for shielding a wireless device under test (“DUT”) from electro-magnetic interference, including other wireless devices; and at least one of: (1) a communications traffic generating device operable to generate communications traffic having selected characteristics; and (2) at least one dynamically adjustable attenuator in communication with the wireless device and the traffic generator. Embodiments of the architecture include wireless test equipment for testing operating range, roaming and capacity. The attenuator is used to adjustably attenuate signals between the device and the traffic generator over time during a test, whereby motion of the device is simulated. By connecting multiple access points, each associated with a dynamically adjustable attenuator, it is possible to force the DUT to roam between access points.

Abstract: A method and apparatus is provided that enables accurate measurement of drop rate and delay in a System Under Test (SUT) by one or more monitoring devices even when the frame error rate of the monitoring devices may be imperfect. During a packet drop measurement process, ancillary information is identified and analyzed to determine if the ancillary information can be used to infer receipt of packets when explicit information regarding receipt is not present. A delay measurement process incorporates the time required to re-transmit packets into the delay measurement to more accurately reflect SUT operation.

Abstract: 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.