Method and apparatus for removing a sector from an active set

• US 7,529,546 B1
• Filed: 11/01/2005
• Issued: 05/05/2009
• Est. Priority Date: 11/01/2005
• Status: Expired due to Fees

• Current Assignee: Sprint Spectrum LLC (Deutsche Telekom AG)
• Original Assignee: Sprint Spectrum LP (Deutsche Telekom AG)
• Inventors: Sigg, Jason P.
• Primary Examiner(s): Afshar; Kamran
• Application Number:
  US11/265,405
• Time in Patent Office: 1,281 Days
• Field of Search: 455517-525, 4554561-4563, 455/69, 455436-444, 370/310, 370/311, 370/318, 370/328, 370331-332, 370338-349
• US Class Current: 455/436
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

Communication on a sector in a mobile station'"'"'s active set is eliminated in order to test whether such elimination has a sufficiently adverse impact on RF communication with the mobile station on the remaining sectors in the active set. If it is determined that the elimination of the sector has a sufficiently adverse impact, communication on the sector is restored. Otherwise, the sector is removed from the mobile station'"'"'s active set, thereby freeing up soft hand-off resources including a channel element and a Walsh code for use by other mobile stations. In one embodiment, if the mobile station seeks to add the removed sector back into its active set, the add-request is denied if the mobile station is stationary, but accepted if the mobile station is moving.

Claims

1. A method for managing communication between one or more base transceiver stations and a mobile station, said communication occurring on an active set of cell sectors, comprising steps of:

a) conducting a test at a base transceiver station wherein the base transceiver station intentionally eliminates communication from the base transceiver station to the mobile station on a selected sector in the active set;

b) determining the effect of the elimination of step a) on communication between the mobile station and at least one other remaining sector in the active set;

c) either restoring communication on the active set or removing the active set sector from the set of active set sectors, based on the determination in step b); and

wherein the selected sector for which communication is eliminated in a) comprises the active set sector which has the current lowest reported mobile station

received power level; and

storing a history of removal of active set sectors for a plurality of mobile stations, the

removals made using step c).

2. The method of claim 1, wherein step a) comprises the step of ceasing transmission on the selected sector.

3. The method of claim 1, wherein step a) comprises the step of transmitting a predetermined bit pattern on the selected sector.

4. The method of claim 1, wherein the method is performed on a forward link.

5. The method of claim 1, wherein the method is performed on a reverse link.

6. The method of claim 1, wherein step b) comprises the step of determining if a forward link transmit power change is requested by the mobile station which increases forward link transmit power on a remaining sector in the active set above a threshold level over a test time period.

7. The method of claim 1, wherein step b) comprises the step of determining whether the base transceiver station has received N consecutive forward link power change requests for increased power from the mobile station, where N is a predetermined integer greater than or equal to 2.

8. The method of claim 1, wherein step b) comprises the step of determining whether the forward link power to the mobile station on one or more remaining sectors in the active set meets or exceeds a threshold level.

9. The method of claim 1, wherein steps a), b) and c) are applied to more than one sector in the active set.

10. The method of claim 9, wherein steps a), b) and c) are applied to all of the sectors in the active set, one at a time.

11. A method for managing communication between one or more base transceiver stations and a mobile station, said communication occurring on an active set of cell sectors, comprising steps of:

a) conducting a test at a base transceiver station wherein the base transceiver station intentionally eliminates communication from the base transceiver station to the mobile station on a selected sector in the active set;

b) determining the effect of the elimination of step a) on communication between the mobile station and at least one other remaining sector in the active set;

c) either restoring communication on the active set or removing the active set sector from the set of active set sectors, based on the determination in step b);

wherein the selected sector in step a) is selected based on utilization of active set sectors in a reverse link from the mobile station to the one or

more base transceiver stations; and

storing a history of removal of active set sectors for a plurality of mobile stations, the removals made using step c).

12. A method for managing communication between one or more base transceiver stations and a mobile station, said communication occurring on an active set of cell sectors, comprising steps of:

a) conducting a test at a base transceiver station wherein the base transceiver station intentionally eliminates communication from the base transceiver station to the mobile station on a selected sector in the active set;

b) determining the effect of the elimination of step a) on communication between the mobile station and at least one other remaining sector in the active set;

c) either restoring communication on the active set or removing the active set sector from the set of active set sectors, based on the determination in step b); and

storing a history of removal of active set sectors for a plurality of mobile stations, the removals made using step c).

13. A method for managing communication between one or more base transceiver stations and a mobile station, said communication occurring on an active set of cell sectors, comprising steps of:

a) conducting a test at a base transceiver station wherein the base transceiver station intentionally eliminates communication from the base transceiver station to the mobile station on a selected sector in the active set;

b) determining the effect of the elimination of step a) on communication between the mobile station and at least one other remaining sector in the active set;

c) either restoring communication on the active set or removing the active set sector from the set of active set sectors, based on the determination in step b); and

receiving a request from a mobile station to add a sector to an active set, wherein the sector requested to be added is one in which communication was previously removed in accordance with step c), and wherein the method further comprises the step of denying the request.

14. The method of claim 13, wherein the request is denied when a determination is made that the mobile station has not substantially moved in the time between the removal of the sector in step (c) and the time the request to add the sector is received.

15. A method for managing communication between one or more base transceiver stations and a mobile station, said communication occurring on an active set of cell sectors, comprising steps of:

a) conducting a test at a base transceiver station wherein the base transceiver station intentionally eliminates communication from the base transceiver station to the mobile station on a selected sector in the active set;

b) determining the effect of the elimination of step a) on communication between the mobile station and at least one other remaining sector in the active set;

c) either restoring communication on the active set or removing the active set sector from the set of active set sectors, based on the determination in step b); and

receiving a request from a mobile station to add a sector to an active set, wherein the sector requested to be added is one in which communication was previously removed in accordance with step c), and wherein the method further comprises the step of granting the request, and wherein the request is granted based on a determination that the mobile station has substantially moved in the time between the removal of the sector in step (c) and the time the request to add the sector is received.

16. In a system of one or more base transceiver stations for communication with a mobile station via a set of active set sectors, comprising steps of:

a processing element and a memory storing machine readable instructions for execution by the processing element, the instructions for causing;

a) one of the base transceiver stations to conduct a test wherein the base transceiver station intentionally eliminates communication with the mobile station on a selected sector in an active set of sectors;

b) a determination of the effect of the elimination in a) on communication between the mobile station and at least one other remaining sector in the active set; and

c) either a restoration of communication on the selected sector or a removal of the selected sector from the active set based on the determination in b);

wherein the system receives a request from a mobile station to add a sector to an active set, wherein the sector requested to be added is one in which communication was removed in accordance with instructions c), and wherein the request is denied.

17. The system of claim 16, wherein the request is denied when a determination is made that the mobile station has not substantially moved in the time between the removal of the sector in accordance with instructions (c) and the time the request to add the sector is received.

18. In a system of one or more base transceiver stations for communication with a mobile station via a set of active set sectors, comprising steps of:

a processing element and a memory storing machine readable instructions for execution by the processing element, the instructions for causing;

a) one of the base transceiver stations to conduct a test wherein the base transceiver station intentionally eliminates communication with the mobile station on a selected sector in an active set of sectors;

b) a determination of the effect of the elimination in a) on communication between the mobile station and at least one other remaining sector in the active set; and

c) either a restoration of communication on the selected sector or a removal of the selected sector from the active set based on the determination in b);

wherein the system receives a request from a mobile station to add a sector to an active set, wherein the sector requested to be added is one in which communication was removed in accordance with instructions c), and wherein the instructions further cause a granting of the request, and wherein the request is granted when a determination is made that the mobile station has substantially moved in the time between the removal of the sector in accordance with instructions (c) and the time the request to add the sector is received.