Xiaoxin X Qiu

US Patent:

6459901, Oct 1, 2002

Filed:

Dec 3, 1999

Appl. No.:

09/453566

Inventors:

Kapil K. Chawla - Scotch Plains NJ
Justin Che-I Chuang - Holmdel NJ
Xiaoxin Qiu - Bridgewater NJ
Nelson Ray Sollenberger - Farmingdale NJ

Assignee:

ATT Corp. - New York NY

International Classification:

H04Q 720

US Classification:

455450, 455 671, 455451, 455452, 370341

Abstract:

This invention provides wireless resource allocation techniques where the wireless network resource allocation is based on maximum system gain. System gain may be the difference between a maximum performance (e. g. , throughput rate) for a requested link and a performance loss of all currently active links affected by the requested link. A currently active link is affected if the requested link is within its link neighborhood. Wireless network resources are allocated to optimize system performance. Inter-base communication may be used to facilitate information exchange among base stations to optimize system performance. The performance loss experienced by any currently active link is called damage to that link. Damage may be determined in a pair-wise fashion based on a nominal performance which may be defined as the performance of a link if interference is experienced only from links which are outside the link neighborhood of the link or as a system parameter. The damage is the difference between the nominal performance and the performance for the link if experiencing interference only from the requested link.

US Patent:

6501765, Dec 31, 2002

Filed:

Sep 1, 1998

Appl. No.:

09/145074

Inventors:

Xiaolin Lu - Matawan NJ
Xiaoxin Qiu - Middletown NJ

Assignee:

ATT Corp. - New York NY

International Classification:

H04L 12413

US Classification:

370447, 370461, 370462, 370463

Abstract:

The invention provides a method and apparatus for end-users to allocate a communication medium locally without requiring a central arbitration device while guaranteeing access to the end-users. The end-users bid for control of an upstream data channel by concurrently transmitting auction data and address data on a first upstream signaling channel and a second upstream signaling channel. An end-user gains control of the upstream data channel when data received from the first and second downstream signaling channels match the auction and address bits. When it is determined that the end-user lost the bid, the end-user backs off from the first and second upstream signaling channels and refrains from bidding until the first and second upstream signaling channels become quiet.

US Patent:

6501785, Dec 31, 2002

Filed:

Dec 28, 1999

Appl. No.:

09/472784

Inventors:

Li Fung Chang - Holmdel NJ
Kapil K. Chawla - Middletown NJ
Justin C. Chuang - Holmdel NJ
Zoran Kostic - Holmdel NJ
Nelson Sollenberger - Tinton Falls NJ
Xiaoxin Qiu - Bridgewater NJ

Assignee:

ATT Corp. - New York NY

International Classification:

H04J 1306

US Classification:

375133, 455452

Abstract:

This invention provides a dynamic frequency hopping system that utilizes information from multiple base stations. The system assigns frequency hopping patterns based on current interference and traffic environments to avoid interference thus gaining the benefits of interference averaging and interference avoidance. The system imposes less stringent measurement requirements on terminals (wireless mobile devices) because many measurement requirements are replaced by generating estimates based on measurement data received from other base stations within a base station neighborhood. The system may continuously verify that the frequency hopping patterns assigned to the links of the system optimizes system performance. The system compares system performance of possible frequency hopping patterns against currently assigned frequency hopping pattern to optimize system performance. When a request for a link is received, a similar process as above is performed where the request is granted/denied/delayed based on system optimization requirements.

US Patent:

6532225, Mar 11, 2003

Filed:

Jul 27, 1999

Appl. No.:

09/361572

Inventors:

Li Fung Chang - Holmdel NJ
Kapil K. Chawla - Middletown NJ
Justin C. Chuang - Holmdel NJ
Xiaoxin Qiu - Bridgewater NJ
Nelson R. Sollenberger - Tinton Falls NJ

Assignee:

ATT Corp - New York NY

International Classification:

H04Q 728

US Classification:

370341

Abstract:

An arrangement where, in addition to the control channels that are used to set up sessions, there is a logically and physically separate and independent set of control channels that can be used as session control channels. Illustratively, the physical GSM frame arrangement that employs 8 logical slots is used, with one slot both in the uplink and downlink dedicated to these separate control channels. In the downlink, such a control channel provides channel grant information, requests to make and transmit power measurements, poll mobile units, etc. In the uplink, such a control channel can be used to request access to a traffic channel, to report on power measurements, to request special hand-off handling, to respond to polling, etc. Because the uplink session control channel does not need to carry a significant amount of information, the GSM slot can be divided into minislots, with each minislot constituting a session control channel for a group of mobile units.

US Patent:

6657982, Dec 2, 2003

Filed:

Jan 27, 2000

Appl. No.:

09/492174

Inventors:

Thomas K. Fong - Aberdeen NJ
Paul Shala Henry - Holmdel NJ
Kin K. Leung - Edison NJ
Xiaoxin Qiu - Middletown NJ
Nemmara K. Shankaranarayanan - Roselle Park NJ

Assignee:

ATT Corp. - New York NY

International Classification:

H04J 300

US Classification:

370336, 370349

Abstract:

A method and apparatus for scheduling transmissions between a plurality of communications sites within a communications system. The communications system provides service to a service area which is divided into sectors. Each sector is assigned a time subframe in a pattern where adjacent sectors use different subframes. Communications sites within each sector communicate packets of information in at least one time subframe according to a schedule to minimize interference from other communications sites.

US Patent:

6681114, Jan 20, 2004

Filed:

Dec 6, 2000

Appl. No.:

09/731345

Inventors:

Li Fung Chang - Holmdel NJ
Hui Luo - Old Bridge NJ
Xiaoxin Qiu - Bridgewater NJ

Assignee:

ATT Corp. - New York NY

International Classification:

H04Q 720

US Classification:

4554563, 4554142, 37911413

Abstract:

An on-demand message system includes a profile proxy server and a plurality of message servers coupled to a wireless network for sending messages to mobile users under conditions specified by the users and sellers. Users provide profile information specifying categories and conditions for which they will receive messages. Sellers also provide profile information specifying conditions under which they want messages to be sent. A multicast message is sent and processed by target users in response to a predetermined event, e. g. , location update, conveying information related to a seller for which the target users have expressed an interest in receiving.

US Patent:

6754506, Jun 22, 2004

Filed:

Feb 16, 2001

Appl. No.:

09/784901

Inventors:

Li Fung Chang - Holmdel NJ
Kapil K. Chawla - Scotch Plains NJ
Justin Chi-I Chuang - Holmdel NJ
Zoran Kostic - Holmdel NJ
Xiaoxin Qiu - Bridgewater NJ
Nelson Ray Sollenberger - Farmingdale NJ
Shailender B. Timiri - Bellevue WA

Assignee:

ATT Wireless Services, Inc. - Redmond WA

International Classification:

H04Q 720

US Classification:

455522, 455 69, 4552451

Abstract:

A TDMA wireless communication system adjusts the power control target and transmission power based upon link quality to enhance voice capacity. The power can be adjusted in response to the average SNIR and number of decoding errors in a link quality reporting period. The power control target can be increased and decreased in discrete intervals after evaluating the number of decoding errors in the reporting period. The transmission power can be adjusted towards the new power control target based upon the average SNIR.

US Patent:

6823005, Nov 23, 2004

Filed:

Aug 9, 1999

Appl. No.:

09/370770

Inventors:

Justin Che-I Chuang - Holmdel NJ
Xiaoxin Qiu - Bridgewater NJ

Assignee:

ATT Corp - New York NY

International Classification:

H04B 1700

US Classification:

375227, 375346, 455510

Abstract:

The present invention implements a method and system for dynamically adapting the modulation and coding scheme for radio links in a wireless communications network based on a retransmission environment model in order to maximize throughput and most efficiently allocate bandwidth resources. The present invention encompasses a refined calculus and methodology for deriving the link adaptation thresholds in a retransmission environment using a complex model and analysis of the retransmission environment. The present invention holds particular application for wireless data communications as opposed to real time data services because it is based on a retransmission model applicable primarily for data services. A critical component of this new link adaptation system is a âno transmissionâ cutoff mode that is selected for SIR below a base threshold value. This new mode prevents system instability and misallocation of bandwidth in a wireless communication system.