Method and system for station location based neighbor determination and handover probability estimation

• US 8,971,293 B2
• Filed: 05/03/2012
• Issued: 03/03/2015
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Olvera-Hernandez, Ulises, Carlton, Alan Gerald
• Primary Examiner(s): WASHINGTON, ERIKA ALISE
• Application Number:
  US13/463,490
• Publication Number:
  US 20120213201A1
• Time in Patent Office: 1,034 Days
• Field of Search: None
• US Class Current: 370/331
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/322 by location data
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

The present invention is a method and system for station location based neighbor determination and handover probability estimation. A serving access point determines the location and movement measurements of a station (STA). Neighboring access points report coordinates of cell fringes of the neighboring access points. The STA sends a request for system information to the current access point along with current location of the STA. The current access point provides the system information, and the STA utilizes the system information to determine best handover candidate from among neighboring access points and an estimate of the time for handover.

Claims

1. A wireless transmit/receive unit (WTRU) configured to perform a handover, the WTRU comprising:

a receiver configured to receive from a current Node-B a weighting factor that is associated with a speed of the WTRU; and

a processor configured to;

rank a plurality of neighbor Node-Bs against the current Node-B, in order of probability of a successful handover, based on a measured signal quality of each the plurality of neighbor Node-Bs, and the weighting factor, and

initiate a handover procedure to a suitable handover candidate Node-B selected from the plurality of neighbor Node-Bs, on a condition that the rank of the suitable handover candidate Node-B is higher than the rank of the current Node-B.

2. The WTRU of claim 1 wherein the weighting factor is also associated with a direction the WTRU is traveling.

3. The WTRU of claim 1 wherein the receiver is further configured to receive network information from the current Node-B.

4. The WTRU of claim 3 wherein the network information includes at least one of:

network topology information, information relating to the current location of a WTRU, and a list of neighbor Node-Bs.

5. The WTRU of claim 1 wherein the measured signal quality of the plurality of neighbor Node-Bs is determined while the WTRU is not transmitting to a current Node-B.

6. A method implemented in a wireless transmit/receive unit (WTRU) configured to perform a handover, the method comprising:

receiving from a current Node-B a weighting factor that is associated with a speed of the WTRU;

ranking a plurality of neighbor Node-Bs against the current Node-B, in order of probability of a successful handover, based on a measured signal quality of each the plurality of neighbor Node-Bs, and the weighting factor, and

initiating a handover procedure to a suitable handover candidate Node-B selected from the plurality of neighbor Node-Bs, on a condition that the rank of the suitable handover candidate Node-B is higher than the rank of the current Node-B.

7. The method of claim 6 wherein the weighting factor is also associated with a direction the WTRU is traveling.

8. The method of claim 6, further comprising:

receiving network information from the current Node-B.

9. The method of claim 8, wherein the network information includes at least one of:

network topology information, information relating to the current location of a WTRU, and a list of neighbor Node-Bs.

10. The method of claim 6, wherein the measured signal quality of the plurality of neighbor Node-Bs is determined while the WTRU is not transmitting to a current Node-B.