Method and system for automated determination of inter-system border thresholds

• US 20080298281A1
• Filed: 08/04/2008
• Published: 12/04/2008
• Est. Priority Date: 06/28/2002
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Hunkeler, Teresa
• Application Number:
  US12/221,532
• Publication Number:
  US 20080298281A1
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/302 due to low signal strength

Abstract

A method and system for determining thresholds for evaluating inter-system handovers in a wireless communication system includes determining a quality level of a first digital duplexing type, determining a quality level of a second digital duplexing type, and comparing the quality levels to determine whether to handover from the first digital duplexing type to the second duplexing type.

Claims

1. A method for operating a multi-mode wireless transmit/receive unit (WTRU) comprising:

receiving signals from both a time division duplex (TDD) and a frequency divisional duplex (FDD) system;

establishing a connection with one of the systems;

measuring a quality of signals received from both the TDD system and the FDD system;

comparing the measured signal quality of the TDD system with a TDD threshold and the measured signal quality of the FDD system with a FDD threshold; and

handing over from a current system in which a connection is established to an other system is the measured signal quality of the current system is below the threshold of the current system and the measured signal quality of the other system is above the threshold of the other system.

2. The method of claim 1, wherein the TDD threshold is determined based on a received signal code power of a primary common control physical channel.

3. The method of claim 1, wherein the FDD threshold is determined based on a received signal code power of a common pilot channel.

4. The method of claim 1, wherein the FDD threshold is determined based on a signal-to-noise ratio of a common pilot channel.

5. A method for determining thresholds for evaluating inter-system handovers comprising:

determining an estimated minimum quality level of a first digital duplexing type based on a threshold value for intra-system handover of the first digital duplexing type;

setting a first handover threshold to said estimated minimum quality level of the first digital duplexing type;

determining an actual quality level of a second digital duplexing type based on information regarding extent of coverage for said second digital duplexing type from a plurality of multi-mode wireless transmit/receive units (WTRUs) comprised in the wireless communication system, said actual quality level representing minimum quality required to sustain communication in second digital duplexing type;

setting a reporting threshold to said actual quality level of the second digital duplexing type;

determining whether an estimated minimum quality level of the second digital duplexing type, which is based on a threshold value for intra-system handover of the second digital duplexing type, is higher than said actual quality level of a second digital duplexing type;

setting a second handover threshold to the reporting threshold when the determination is positive; and

setting the second handover threshold to said estimated minimum quality level of the second digital duplexing type when the determination is negative.

6. The method of claim 5, wherein the estimated minimum quality level of the first digital duplexing type is determined by a WTRU using primary channel signal levels.

7. The method of claim 6, wherein the estimated minimum quality level of the second digital duplexing type is determined by a WTRU using secondary channel signal levels derived from an estimated quality of a non-used frequency.

8. The method of claim 5, wherein the first digital duplexing type is time division duplex and the second digital duplexing type is frequency division duplex.

9. The method of claim 5, wherein the first digital duplexing type is frequency division duplex and the second digital duplexing type is time division duplex.

10. The method of claim 5, wherein the quality level of the first digital duplexing type is based on a received signal code power of a primary common control physical channel.

11. The method of claim 5, wherein the first threshold in as average value of estimated minimum quality level values of the first digital duplexing type, and the second threshold is an average value of the estimated minimum quality level values of the second digital duplexing type.

12. The method of claim 5, wherein the first threshold and the second threshold are percentile values.

13. The method of claim 5, wherein the first duplexing type is Time Division Duplex (TDD) and the second duplexing type is Frequency Division Duplex (FDD).

14. The method of claim 5, wherein the first duplexing type is Frequency Division Duplex (FDD) and the second duplexing type is Time Division Duplex (TDD).

15. The method of claim 5, wherein the determining of estimated minimum quality level values includes calculating a received signal code power of a primary common control physical channel.

16. The method of claim 5, wherein the determining of estimated minimum quality level values includes calculating a received signal code power of a common pilot channel.

17. The method of claim 5, wherein the determining of estimated minimum quality level values includes calculating a signal-to-noise ratio of a common pilot channel.