Alexe E Leu

US Patent:

7218933, May 15, 2007

Filed:

Mar 10, 2005

Appl. No.:

11/075983

Inventors:

Brian Mark - Fairfax VA, US
Alexe E. Leu - Arlington VA, US

Assignee:

George Mason Intellectual Properties, Inc. - Fairfax VA

International Classification:

H04Q 7/20

US Classification:

455437, 455439, 455438, 455436, 370331, 370332

Abstract:

Disclosed is a cellular network handoff decision mechanism which comprising the steps of: determining a sampling interval using a carrier wavelength; determining a local averaging interval that is larger than the sampling interval; determining a handoff decision interval that is larger than the local averaging interval; selecting at least two base stations from a multitude of base stations having a pilot signal from a reference cellular network using a selection criterion; determining a received signal strength from the pilot signal strength for each of the selected base stations once during every sampling interval; calculating a local average signal strength value using each of the received signal strengths once during every local averaging interval; determining an assignment region in which the local average signal strength value lies using a hysteresis range; and calculating a handoff decision once during every handoff decision interval using a handoff calculation.

US Patent:

7564816, Jul 21, 2009

Filed:

May 12, 2006

Appl. No.:

11/432536

Inventors:

Mark Allen McHenry - McLean VA, US
Alexe E. Leu - Arlington VA, US

Assignee:

Shared Spectrum Company - Vienna VA

International Classification:

H04W 4/00
H04B 17/00

US Classification:

370329, 455 6713

Abstract:

A method and transceiver for determining spectrum availability within a give area is disclosed. The given area includes cells in a grid. A belief evaluator receives a measurement from a signal and assigns an instantaneous belief indicator, an instantaneous disbelief indicator and an instantaneous ignorance indicator based on a detection threshold and the power level of the measurement. The indicators quantify the probability of a presence of a transmitter within the grid cell. A belief accumulator uses the instantaneous indicators along with accumulated belief, disbelief and ignorance indicators from previous measurements to determine cumulative belief, disbelief and ignorance indicators. The accumulated belief, disbelief and ignorance indicators are the results of previous measurements and belief/disbelief/ignorance determinations for the grid cell. An allocator indicates the status of the grid cell and whether a spectrum is available. If a spectrum is available, then the grid cell is added to other available cells within the area to generate the spectrum hole.

US Patent:

8064840, Nov 22, 2011

Filed:

Jun 18, 2009

Appl. No.:

12/487257

Inventors:

Mark Allen McHenry - McLean VA, US
Alexe E. Leu - Arlington VA, US

Assignee:

Shared Spectrum Company - Vienna VA

International Classification:

H04B 17/00

US Classification:

455 6716

Abstract:

A method and transceiver for determining spectrum availability within a give area is disclosed. The given area includes cells in a grid. A belief evaluator receives a measurement from a signal and assigns an instantaneous belief indicator, an instantaneous disbelief indicator and an instantaneous ignorance indicator based on a detection threshold and the power level of the measurement. The indicators quantify the probability of a presence of a transmitter within the grid cell. A belief accumulator uses the instantaneous indicators along with accumulated belief, disbelief and ignorance indicators from previous measurements to determine cumulative belief, disbelief and ignorance indicators. The accumulated belief, disbelief and ignorance indicators are the results of previous measurements and belief/disbelief/ignorance determinations for the grid cell. An allocator indicates the status of the grid cell and whether a spectrum is available. If a spectrum is available, then the grid cell is added to other available cells within the area to generate the spectrum hole.

US Patent:

7181221, Feb 20, 2007

Filed:

Sep 26, 2003

Appl. No.:

10/670467

Inventors:

Brian L. Mark - Fairfax VA, US
Alexe E. Leu - Arlington VA, US

Assignee:

George Mason Intellectual Properties, Inc. - Fairfax VA

International Classification:

H04Q 7/20

US Classification:

455436, 455443, 370331

Abstract:

Disclosed is a system for evaluating the performance of cellular network handoff decisions. One embodiment of this system includes the steps of: creating a reference cellular network description; creating reduced geometric structures from the reference cellular network description; representing a general trajectory for a mobile unit in the reference cellular network description; approximating the general trajectory with a piecewise path having a multitude of handoff decision points; selecting a handoff mechanism; selecting handoff parameters; creating a discrete-time formulation characterizing handoff behaviors; and calculating at least one handoff performance metric. The handoff performance metrics may include assignment probabilities; handoff probabilities; a mean number of handoff value; a crossover point; and overall signaling load incurred by a handoff mechanism.