Apple Inc.

Juniper Networks, Inc.

Thomas W Chang

Steven A Malmskog

Michel Hoche-Mong

Justin Lawrence Gregg

Peter I Bevelacqua

Adil Syed

David A Donovan

A method for testing wireless devices under test (DUTs) in a wireless test station is provided. Each test station may include a test unit, a test chamber with an antenna, and a radio-frequency (RF) cable that connects the test unit to the test chamber. Reference DUTs may be used to calibrate each test station to compute a corrected linear equation based on a nominal path loss value. Over-the-air (OTA) path loss of each test station may not be directly measured. Once calibrated, the test chambers may be used during product testing to test factory DUTs to determine whether a particular factory DUT satisfies pass/fail criteria. During product testing, measured output power levels may be compared with expected output power levels computed using the corrected linear equation. The amount of error between the measured and expected output power levels will determine whether a production DUT satisfies the pass/fail criteria.

Methods of testing wireless devices in over-the-air radio-frequency test systems without path loss characterization

Calibration equipment for calibrating multiple test stations in a test system is provided. Each test station may include a test unit, a test chamber with an over-the-air (OTA) antenna, and a radio-frequency (RF) cable that connects the test unit to the test chamber. Reference devices under test (DUTs) may be used to calibrate the OTA path loss of each test station at desired frequencies. Once calibrated, the test chambers may be used during production testing to test factory DUTs to determine whether a particular production DUT is a passing or failing DUT according to pass/fail criteria. A running average path loss value may be constantly updated based on path loss values measured using the reference DUTs and the passing production DUTs. Dynamically updating the path loss value using this statistical approach can properly track the behavior of each test station as operating conditions shift over time.

Methods for dynamic calibration of over-the-air path loss in over-the-air radio-frequency test systems

Calibration equipment for calibrating multiple test stations in a test system is provided. Each test station may include a test unit, a test chamber with multiple antennas, and radio-frequency (RF) cables that connect the test unit to the multiple antennas within the test chamber. Reference devices under test (DUTs) may be used to calibrate the OTA path loss of each test station while switching one of the multiple antennas into use one at a time at desired frequencies. A preferred antenna list indicating the preferred antenna that provides the optimal path loss for each desired frequency may be generated. Once calibrated, the test stations may be used during product testing to test factory DUTs to determine whether a particular production DUT satisfies pass/fail criteria. During product testing, a selected one of the multiple antennas is enabled based on the preferred antenna list to perform desired measurements.

Test systems with multiple antennas for characterizing over-the-air path loss

A network acceleration device includes a persistent, in-memory cache of network content. For example, the cache may store content in a manner that allows a software process to map virtual memory to specific, known regions of an underlying physical memory. Upon detecting a failure of a process executing within the network device, the network acceleration device may restart the software process and remap data structures of the cache to the known regions of the physical memory without necessarily requiring that the cache content be reloaded from a non-volatile memory, such as a hard drive. In this manner, the network acceleration device may accelerate download speeds by avoiding timely cache content restoration in the event of a software process failure.

Network acceleration device having persistent in-memory cache

A network acceleration device provides application programming interface (API) that facilitates the sharing of cache resources among multiple network acceleration devices, thereby allowing the network acceleration devices to be clustered and share a common cache of network content. This clustered approach may advantageously allow clients serviced by one network acceleration device to benefit from previous network access requests issued by clients serviced by a different network acceleration device of the cluster.

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Sunnyvale, CA, United States of America

Thomas W Chang