Cheng Liu

US Patent:

7792051, Sep 7, 2010

Filed:

Dec 17, 2007

Appl. No.:

11/957905

Inventors:

Jeffrey Aaron - Atlanta GA, US
Cheng P. Liu - Johns Creek GA, US

Assignee:

AT&T Intellectual Property I, L.P. - Reno NV

International Classification:

G01R 31/08
H04J 3/16
H04W 72/00

US Classification:

370252, 370468, 4554522

Abstract:

Quality of service is provided, for applications using a wireless network, by adapting the operation of the application to changes in operation of the wireless network, instead of attempting to command the wireless network to adapt to the application. Adaptation is accomplished by collecting pertinent RF data concerning operation of the wireless network and pre-calculating at least one anticipated operational characteristic of that network based on operational dynamics determined from the pre-calculation. Pre-calculation may include trend projection to predict near-term future operation expected from the wireless network. The pre-calculated operational characteristic is provided to the application so that operation of the application may adapt to the anticipated dynamic variations in operation of the wireless network.

US Patent:

8064938, Nov 22, 2011

Filed:

Mar 31, 2009

Appl. No.:

12/415124

Inventors:

Jeffrey A. Aaron - Atlanta GA, US
Cheng P. Liu - Duluth GA, US

Assignee:

AT&T Mobility II LLC - Atlanta GA

International Classification:

H04B 7/00

US Classification:

455509, 4554522

Abstract:

System(s) and method(s) that, periodically or when triggered, adapt data rates in multiple tiers of a network are presented. A top tier feedback (FB) loop adapts on a longer time scale associated with its longer path transit time for FB communication messages from a wireless portion to a data source in the wire-line portion of the network. A bottom tier FB loop adapts very quickly, and on a shorter time scale that the top tier FB loop due to its shorter FB path transit time, at the wireless edge with sufficient speed to accurately adapt to fast-changing wireless conditions. The top tier provides efficient resource utilization down to the bottom tier, and the bottom tier provides efficient resource utilization within the wireless portion of the network. A middle tier(s) can be added as desired to provide a more gradual stepped adaptation from source to destination.

US Patent:

8180385, May 15, 2012

Filed:

Jun 30, 2009

Appl. No.:

12/494551

Inventors:

Jeffrey A. Aaron - Atlanta GA, US
Cheng P. Liu - Duluth GA, US

Assignee:

AT&T Intellectual Property I, L.P. - Atlanta GA

International Classification:

H04B 7/00

US Classification:

455509, 455450, 4554522, 370329

Abstract:

System(s) and method(s) that, periodically or when dynamically triggered, adapt data rates associated with user equipment (UE) in a network are presented. When the UE uses an application or a service, data traffic associated with the UE is inspected to obtain information relating to the application or service, which is used to determine an application/service margin. Current and historical information relating to communication conditions associated with the UE and an associated user is obtained to facilitate determining expected values of Quality-of-Service factors and communication condition metrics associated with the UE and thereby a volatility margin. For each adaptation time interval, the data rate can be adapted by determining a preliminary data rate and adjusting the preliminary data rate using the application/service margin and volatility margin to obtain the adapted data rate to be used for data communications between a node and the UE in the network.

US Patent:

8270315, Sep 18, 2012

Filed:

Sep 7, 2010

Appl. No.:

12/876548

Inventors:

Jeffrey Aaron - Atlanta GA, US
Cheng P. Liu - Atlanta GA, US

Assignee:

AT&T Intellectual Property I, LP - Atlanta GA

International Classification:

G01R 31/08
H04J 1/16
H04W 4/00
H04W 72/00
H04W 24/00

US Classification:

370252, 370328, 4554522, 4554561

Abstract:

A method for adapting quality of service to dynamics of a wireless telecommunications network is provided. The method includes collecting data relating to operation of an element in the network, wherein the collected data comprises radio-frequency (RF) data relating to operation of the network. The method also includes pre-calculating, from the collected data, a dynamic operational characteristic of the network, wherein the pre-calculating includes pre-calculating from the collected data to obtain a geometrical determination based on a geographical location of a wireless communications device within the network. The method further includes making available the pre-calculated characteristic of the network to an application of the device using the network, including storing the characteristic at a pre-calculation server accessible by the device so the device can selectively retrieve the characteristic, and updating the characteristic at a frequency based on a trigger related to volatility of the RF data being collected.

US Patent:

8295882, Oct 23, 2012

Filed:

Oct 18, 2010

Appl. No.:

12/906277

Inventors:

James Fan - San Ramon CA, US
Richard Kuo - Mountain View CA, US
Cheng P. Liu - Duluth GA, US

Assignee:

AT&T Intellectual Property I, LP - Atlanta GA

International Classification:

H04B 1/38

US Classification:

455558, 455415, 455418, 4554351

Abstract:

Systems, methods, and computer program products are for managing access to a femtocell coverage area. An exemplary method includes storing in a memory component a first identifier corresponding to a subscribed service of a communication device and a second identifier corresponding to a user of the communication device, and granting access to the femtocell coverage area using the second identifier.

US Patent:

8472809, Jun 25, 2013

Filed:

Apr 13, 2011

Appl. No.:

13/085715

Inventors:

Cheng Liu - Smyrna GA, US
Kieran Parsons - Cambridge MA, US

Assignee:

Mitsubishi Electric Research Laboratories, Inc. - Cambridge MA

International Classification:

H04B 10/00

US Classification:

398152

Abstract:

For coherent fiber optic communications, the nonlinear XPolM impairment is the most important issue to realize over-100 Gbps high-speed transmissions. A method provides a way to cancel time-varying XPolM crosstalk by introducing multi-stage adaptive mechanism. In the method, a low-complexity adaptive filtering based on recursive least-squares (RLS) first tracks the time-varying crosstalk along with the per-survivor trellis-state decoding. The estimated channel and the decoded data are then used to calculate the empirical covariance, which is in turn exploited to obtain more accurate channel estimates by means of optimal-weighted least-squares. This is performed with a low-complexity processing over frequency domain with fast Fourier transform. The performance is significantly improved with turbo principle decoding, more specifically, iterative decoding and iterative estimation over a block.

US Patent:

8526913, Sep 3, 2013

Filed:

Oct 8, 2012

Appl. No.:

13/647019

Inventors:

Richard Kuo - Mountain View CA, US
Cheng P Liu - Duluth GA, US

Assignee:

AT&T Intellectual Property I, L.P. - Atlanta GA

International Classification:

H04M 1/66

US Classification:

455410, 455411, 4554351

Abstract:

Systems, methods, and computer program products are for managing access to a femtocell coverage area. An exemplary method includes storing in a memory component a first identifier corresponding to a subscribed service of a communication device and a second identifier corresponding to a user of the communication device, and granting access to the femtocell coverage area using the second identifier.

US Patent:

20100128677, May 27, 2010

Filed:

Nov 20, 2009

Appl. No.:

12/623223

Inventors:

Cheng P. Liu - Duluth GA, US
Alireza Faryar - Fair Haven NJ, US
Kurt Huber - Coral Springs FL, US
Sangar Dowlatkhah - Alpharetta GA, US

International Classification:

H04W 4/00

US Classification:

370328

Abstract:

A system and methodology that facilitates service continuity when a user equipment (UE), employing local breakout mechanisms at a femto access point (FAP) for a communication session, moves out of the femto coverage area is provided. In particular, a network change detection component can be employed to detect when the UE, attached to the FAP, changes its connection from the femto network to the macro network. Further, an active communication session can exist between the UE and a device/service/application on a local Area network (LAN) connected to a FAP, and/or the Internet, which utilizes local breakout at the FAP. When the UE moves out of the femto network, a context management component can be employed to seamlessly resume the communication session, via the macro network.