Evaluation of handoff in wireless networks using emulation

A method to emulate handoff to test at least one Device Under Test in a System Under Test, comprising the steps of:

• emulating, with at least one test device, operation of a plurality of wireless client devices, thereby providing virtual mobile devices;
• and
• storing, with a motion emulator including a memory, a representation of the System Under Test including, for each virtual mobile device, a model of the distance between the virtual mobile device and each Device Under Test, and a model of motion of the virtual mobile device relative to each Device Under Test,
• the motion emulator being operable to calculate, for each Device Under Test, an indication of path loss to be applied to communications between the virtual mobile device and the Device Under Test attributable to the modeled distance and modeled motion, and to transmit the indication of path loss to at least one test device,
• the test device being operable in response to the indication of path loss to apply the path loss to communications between the virtual mobile device and the Device Under Test,
• wherein the path loss applied to communications received by the virtual mobile device from the Device Under Test is virtually adjusted, each test device includes at least one algorithm operable to process the indication of path loss received from the motion emulator in order to virtually adjust signal strength received by each virtual mobile device, and further including an algorithm operable to prompt discard of a data unit based at least in-part on the magnitude of the indicated signal strength.

Apparatus operable to evaluate handoff to test at least one Device Under Test in a System Under Test, comprising:

• a plurality of test devices, each test device operable to emulate operation of a plurality of wireless access points, thereby providing virtual access points;
• and
• a motion emulator including a memory with a representation of the System Under Test including, for each virtual access point, a modeled distance between that virtual access point and each Device Under Test, and a modeled motion of that virtual access point relative to each Device Under Test,
• the motion emulator being operable to calculate, for each Device Under Test, an indication of path loss to be applied to communications between that Device Under Test and the virtual access point attributable to the modeled distance and modeled motion, and to transmit the indication of path loss to at least one test device,
• the test device being operable in response to the indication of path loss to apply the path loss to communications between that Device Under Test and the virtual access point,
• wherein the path loss applied to communications received by a virtual access point from a Device Under Test is virtually adjusted, each test device includes at least one algorithm operable to process the indication of path loss received from the motion emulator in order to virtually adjust signal strength received by each virtual access point, and further including an algorithm operable to prompt discard of a data unit based at least in-part on the magnitude of the indicated signal strength.

A method to evaluate handoff to test at least one Device Under Test in a System Under Test, comprising the steps of:

• emulating, with ones of a plurality of test devices, operation of a plurality of wireless access points, thereby providing virtual access points;
• and
• storing, with a motion emulator including a memory, a representation of the System Under Test including, for each virtual access point, a modeled distance between that virtual access point and each Device Under Test, and a modeled motion of that virtual access point relative to each Device Under Test,
• the motion emulator being operable to calculate, for each Device Under Test, an indication of path loss to be applied to communications between that Device Under Test and the virtual access point attributable to the modeled distance and modeled motion, and to transmit the indication of path loss to at least one test device,
• the test device being operable in response to the indication of path loss to apply the path loss to communications between that Device Under Test and the virtual access point,
• wherein the path loss applied to communications received by a virtual access point from a Device Under Test is virtually adjusted, each test device includes at least one algorithm operable to process the indication of path loss received from the motion emulator in order to virtually adjust signal strength received by each virtual access point, and further including an algorithm operable to prompt discard of a data unit based at least in-part on the magnitude of the indicated signal strength.

Apparatus operable to test at least one Device Under Test in a System Under Test, comprising:

• at least one test device, each test device operable to emulate behavior of at least one wireless client device;
• at least one programmable emulator that allows a user to control the emulated wireless client device;
• and
• at least one filter operable to intercept a data unit at any layer of the protocol stack.

A method to test at least one Device Under Test in a System Under Test, comprising the steps of:

• emulating, with at least one test device, behavior of at least one wireless client device;
• allowing, via at least one programmable emulator, a user to control the emulated wireless client device;
• and
• intercepting a data unit at any layer of the protocol stack using at least one filter.