ANCHOR CARRIER RESELECTION AND CELL RESELECTION IN LONG TERM EVOLUTION-ADVANCED

• US 20100222060A1
• Filed: 02/23/2010
• Published: 09/02/2010
• Est. Priority Date: 02/27/2009
• Status: Abandoned Application

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Inventors: Wang, Peter S., Wang, Jin, Zhang, Guodong
• Application Number:
  US12/710,743
• Publication Number:
  US 20100222060A1
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0069 in case of dual connectivity, e.g. decoupled uplink/downlink
• CPC Class Codes: H04W 36/00692 using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] allocation of physical resources in CoMP or in CA H04L5/0035
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/304 due to measured or perceived resources with higher communication quality

Abstract

A method and apparatus for performing anchor carrier reselection measurements and ranking in Long Term Evolution-Advanced are disclosed. The measurements are first determined by whether a non-serving anchor carrier has a higher reselection priority than a serving anchor carrier. Other non-serving anchor carrier measurements are started by checking the serving anchor measured results against non-serving anchor carrier measurement thresholds, including the parameter S-IntraCellSearch for measuring and ranking the intra-cell anchor carriers ahead of other non-serving anchor carriers.

Claims

1. A method for determining anchor carrier reselection candidates, comprising:

performing measurements on a serving anchor carrier;

determining whether to perform measurements on non-serving anchor carriers; and

ranking the measured non-serving anchor carriers to determine a reselection candidacy order for the measured non-serving anchor carriers.

2. The method according to claim 1, wherein performing measurements on the serving anchor carrier and on the non-serving anchor carriers includes measuring signal strength or signal quality.

3. The method according to claim 1, wherein the determining includes determining whether the serving anchor carrier measurements are below a predetermined threshold.

4. The method according to claim 3, wherein the predetermined threshold is a cell reselection criteria and the method further comprises:

on a condition that the serving anchor carrier measurement is below the cell reselection criteria, performing measurements on all known non-serving anchor carriers.

5. The method according to claim 3, wherein the predetermined threshold is an intra-cell search criteria and the method further comprises:

on a condition that the serving anchor carrier measurement is below the intra-cell search criteria, performing measurements on intra-cell neighbor anchor carriers.

6. The method according to claim 3, wherein the predetermined threshold is an intra-frequency search criteria and the method further comprises:

on a condition that the serving anchor carrier measurement is below the intra-frequency search criteria, performing measurements on intra-frequency neighbor anchor carriers.

7. The method according to claim 3, wherein the predetermined threshold is an inter-frequency search criteria and the method further comprises:

on a condition that the serving anchor carrier measurement is below the inter-frequency search criteria, performing measurements on inter-frequency neighbor anchor carriers.

8. The method according to claim 1, wherein the determining includes determining whether a non-serving anchor carrier has a higher reselection priority than the serving anchor carrier and the method further comprises:

on a condition that a non-serving anchor carrier has a higher reselection priority than the serving anchor carrier, performing measurements on the non-serving anchor carriers having a higher reselection priority than the serving anchor carrier.

9. The method according to claim 1, wherein on a condition that more than one anchor carrier has a same ranking, ranking an intra-cell anchor carrier ahead of an intra-frequency anchor carrier and ranking an intra-frequency anchor carrier ahead of an inter-frequency anchor carrier.

10. The method according to claim 1, further comprising:

normalizing the ranking based on a predetermined number of priority levels.

11. A wireless transmit/receive unit, comprising:

an antenna;

a transceiver in communication with the antenna; and

a processor in communication with the transceiver, the processor configured to;

perform measurements on a serving anchor carrier;

determine whether to perform measurements on non-serving anchor carriers; and

rank the measured non-serving anchor carriers to determine a reselection candidacy order for the measured non-serving anchor carriers.

12. A method for determining whether a wireless transmit/receive unit (WTRU) may access a carrier, comprising:

receiving an indication whether the carrier is barred or reserved for use; and

on a condition that the indication indicates that the carrier is barred or reserved for use, preventing the WTRU from accessing the carrier.

13. The method according to claim 12, wherein a carrier that is reserved for use is reserved for predetermined WTRU access classes and a WTRU with a lower access class may not access the reserved carrier.

14. The method according to claim 12, wherein on a condition that the carrier is barred, the method further comprising:

determining whether a timer associated with the barred status of the carrier has expired; and

on a condition that the timer has expired, permitting the WTRU to attempt to access the carrier.

15. A method for determining whether a carrier is suitable for a wireless transmit/receive unit (WTRU) to camp on, the method comprising:

receiving system information;

examining the system information to determine a functionality of the carrier, wherein the carrier functionality includes at least one of;

frequency range, radio coverage area, Long Term Evolution version compatibility, or resource carrier status; and

using the carrier functionality to determine whether the carrier is suitable for a WTRU to camp on.

16. A method for measuring a carrier by a wireless transmit/receive unit (WTRU) in WTRU operating state measurement, the method comprising:

measuring at least one of;

received signal strength, received signal quality, or path loss; and

measuring on any one of;

a single component carrier, several carriers, or all carriers of a cell.

17. The method of claim 16, wherein on a condition that there are several carriers from a same enhanced Node B on a contiguous frequency spectrum, the measuring including measuring one carrier as being representative of the several carriers.

18. The method of claim 17, wherein the one carrier is identified by any one of:

explicit assignment by the network, explicit configuration by the network, a default carrier, a lowest frequency carrier of the several carriers, a highest frequency carrier of the several carriers, or a carrier currently serving the WTRU.