Method and system for dynamic soft handoff resource allocation in a wireless network

• US 7,346,354 B2
• Filed: 02/07/2005
• Issued: 03/18/2008
• Est. Priority Date: 06/09/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Patel, Achal R.
• Primary Examiner(s): Perez-Gutierrez; Rafael
• Assistant Examiner(s): SHEDRICK, CHARLES TERRELL
• Application Number:
  US11/053,323
• Publication Number:
  US 20050153697A1
• Time in Patent Office: 1,135 Days
• Field of Search: 370/335, 455/450, 455/452.1, 455/451, 455/453
• US Class Current: 455/450
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 4/24 Accounting or billing
• CPC Class Codes: H04W 40/02 Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and system for dynamic soft handoff resource allocation in a wireless communications network includes determining a wireless path characteristic individually for each path of a macro diversity connection between a mobile device and a plurality of wireless sites. Wireless resources are allocated for the macro diversity connection between the mobile device and the wireless sites based on the wireless path characteristic. The wireless path characteristic includes a location-based characteristic, a congestion-based characteristic, a subscriber-based characteristic and/or a performance-based characteristic.

Claims

1. A method for allocating one or more resources in a wireless network, comprising:

receiving from a mobile device a request for a set of cells, the mobile device operable to communicate information over a wireless link, each cell associated with a bandwidth;

estimating an available bandwidth for each cell of the set of cells;

determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link, the bias for a cell indicating a portion of the bandwidth of the cell to be allocated to the wireless link, the bias for a cell determined in accordance with the available bandwidth for the cell;

establishing a resource allocation for each cell in accordance with the bias for the each cell if there is an assignment of a bias for each cell that is operable to maintain the link; and

accepting a connection for the mobile device even if there is no resource allocation for one cell of the set of cells that is operable to maintain the wireless link.

2. The method of claim 1, wherein the set of cells comprises one or more cells identified by the mobile device as active.

3. The method of claim 1, wherein estimating the available bandwidth for each cell of the set of cells further comprises repeating the following for each cell of the set of cells:

establishing a total transmit power of a cell;

estimating a current transmit power of the cell; and

calculating a difference between the total transmit power and the current transmit power to estimate the available bandwidth for the cell.

4. The method of claim 1, wherein determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link further comprises:

associating a first bias to a first cell having a first available bandwidth; and

associating a second bias to a second cell having a second available bandwidth, the second bias greater than the first bias, the second available bandwidth larger than the first available bandwidth, a greater bias indicating a larger portion of bandwidth to be allocated.

5. The method of claim 1, wherein determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link further comprises:

selecting a cell from the set of cells as a member of a set of selected cells; and

repeating the following until at least one of the following occurs;

an assignment of a bias for each cell that is operable to maintain the link is determined, and a last cell of the set of cells is reached;

determining that there is an assignment of a bias for each cell that is operable to maintain the wireless link if there is an assignment of a bias for each cell of the set of selected cells that is operable to maintain the wireless link; and

otherwise, selecting a next cell from the set of cells as a member of the set of selected cells.

6. The method of claim 1, wherein establishing the resource allocation for each cell in accordance with the bias for the each cell further comprises repeating the following for each cell of the set of cells:

weighting the bandwidth of the cell according to the bias for the cell.

7. The method of claim 1, further comprising rejecting a connection for the mobile device if there is no assignment of a bias for each cell that is operable to maintain the wireless link.

8. A system for allocating one or more resources in a wireless network, comprising:

an interface operable to receive from a mobile device a request for a set of cells, the mobile device operable to communicate information over a wireless link, each cell associated with a bandwidth; and

one or more subsystems coupled to the interface and operable to;

estimate an available bandwidth for each cell of the set of cells;

determine whether there is an assignment of a bias for each cell that is operable to maintain the wireless link, the bias for a cell indicating a portion of the bandwidth of the cell to be allocated to the wireless link, the bias for a cell determined in accordance with the available bandwidth for the cell;

establish a resource allocation for each cell in accordance with the bias for the each cell if there is an assignment of a bias for each cell that is operable to maintain the link; and

accept a connection for the mobile device even if there is no resource allocation for one cell of the set of cells that is operable to maintain the wireless link.

9. The system of claim 8, wherein the set of cells comprises one or more cells identified by the mobile device as active.

10. The system of claim 8, the one or more subsystems further operable to estimate the available bandwidth for each cell of the set of cells by repeating the following for each cell of the set of cells:

establishing a total transmit power of a cell;

estimating a current transmit power of the cell; and

calculating a difference between the total transmit power and the current transmit power to estimate the available bandwidth for the cell.

11. The system of claim 8, the one or more subsystems further operable to determine whether there is an assignment of a bias for each cell that is operable to maintain the wireless link by:

associating a first bias to a first cell having a first available bandwidth; and

associating a second bias to a second cell having a second available bandwidth, the second bias greater than the first bias, the second available bandwidth larger than the first available bandwidth, a greater bias indicating a larger portion of bandwidth to be allocated.

12. The system of claim 8, the one or more subsystems further operable to determine whether there is an assignment of a bias for each cell that is operable to maintain the wireless link by:

selecting a cell from the set of cells as a member of a set of selected cells; and

repeating the following until at least one of the following occurs;

an assignment of a bias for each cell that is operable to maintain the link is determined, and a last cell of the set of cells is reached;

determining that there is an assignment of a bias for each cell that is operable to maintain the wireless link if there is an assignment of a bias for each cell of the set of selected cells that is operable to maintain the wireless link; and

otherwise, selecting a next cell from the set of cells as a member of the set of selected cells.

13. The system of claim 8, the one or more subsystems further operable to establish the resource allocation for each cell in accordance with the bias for the each cell by repeating the following for each cell of the set of cells:

weighting the bandwidth of the cell according to the bias for the cell.

14. The system of claim 8, the one or more subsystems further operable to reject a connection for the mobile device if there is no assignment of a bias for each cell that is operable to maintain the wireless link.

15. A computer-readable medium encoded with a computer program to perform a method for allocating one or more resources in a wireless network, the method comprising:

receiving from a mobile device a request for a set of cells, the mobile device operable to communicate information over a wireless link, each cell associated with a bandwidth;

estimating an available bandwidth for each cell of the set of cells;

determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link, the bias for a cell indicating a portion of the bandwidth of the cell to be allocated to the wireless link, the bias for a cell determined in accordance with the available bandwidth for the cell;

establishing a resource allocation for each cell in accordance with the bias for the each cell if there is an assignment of a bias for each cell that is operable to maintain the link; and

accepting a connection for the mobile device even if there is no resource allocation for one cell of the set of cells that is operable to maintain the wireless link.

16. The method of claim 15, wherein the set of cells comprises one or more cells identified by the mobile device as active.

17. The method of claim 15, further comprising estimating the available bandwidth for each cell of the set of cells by repeating the following for each cell of the set of cells:

establishing a total transmit power of a cell;

estimating a current transmit power of the cell; and

calculating a difference between the total transmit power and the current transmit power to estimate the available bandwidth for the cell.

18. The method of claim 15, further comprising determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link by:

associating a first bias to a first cell having a first available bandwidth; and

associating a second bias to a second cell having a second available bandwidth, the second bias greater than the first bias, the second available bandwidth larger than the first available bandwidth, a greater bias indicating a larger portion of bandwidth to be allocated.

19. The method of claim 15, further comprising determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link by:

selecting a cell from the set of cells as a member of a set of selected cells; and

repeating the following until at least one of the following occurs;

an assignment of a bias for each cell that is operable to maintain the link is determined, and a last cell of the set of cells is reached;

determining that there is an assignment of a bias for each cell that is operable to maintain the wireless link if there is an assignment of a bias for each cell of the set of selected cells that is operable to maintain the wireless link; and

otherwise, selecting a next cell from the set of cells as a member of the set of selected cells.

20. The method of claim 15, further comprising establishing the resource allocation for each cell in accordance with the bias for the each cell by repeating the following for each cell of the set of cells:

weighting the bandwidth of the cell according to the bias for the cell.

21. The method of claim 15, further comprising rejecting a connection for the mobile device if there is no assignment of a bias for each cell that is operable to maintain the wireless link.

22. A system for allocating one or more resources in a wireless network, comprising:

means for receiving from a mobile device a request for a set of cells, the mobile device operable to communicate information over a wireless link, each cell associated with a bandwidth;

means for estimating an available bandwidth for each cell of the set of cells;

means for determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link, the bias for a cell indicating a portion of the bandwidth of the cell to be allocated to the wireless link, the bias for a cell determined in accordance with the available bandwidth for the cell;

means for establishing a resource allocation for each cell in accordance with the bias for the each cell if there is an assignment of a bias for each cell that is operable to maintain the link; and

means for accepting a connection for the mobile device even if there is no resource allocation for one cell of the set of cells that is operable to maintain the wireless link.

23. A method for allocating one or more resources in a wireless network, comprising:

receiving from a mobile device a request for a set of cells, the mobile device operable to communicate information over a wireless link, the set of cells comprising one or more cells identified by the mobile device as active, each cell associated with a bandwidth;

estimating an available bandwidth for each cell of the set of cells by repeating the following for each cell of the set of cells;

establishing a total transmit power of a cell;

estimating a current transmit power of the cell; and

calculating a difference between the total transmit power and the current transmit power to estimate the available bandwidth for the cell;

determining whether there is an assignment of a bias for each cell that is operable to maintain the wireless link, the bias for a cell indicating a portion of the bandwidth of the cell to be allocated to the wireless link, the bias for a cell determined in accordance with the available bandwidth for the cell by;

selecting a cell from the set of cells as a member of a set of selected cells; and

repeating the following until at least one of the following occurs;

an assignment of a bias for each cell that is operable to maintain the link is determined, and a last cell of the set of cells is reached;

determining that there is an assignment of a bias for each cell that is operable to maintain the wireless link if there is an assignment of a bias for each cell of the set of selected cells that is operable to maintain the wireless link; and

otherwise, selecting a next cell from the set of cells as a member of the set of selected cells, the determination further made by;

associating a first bias to a first cell having a first available bandwidth; and

associating a second bias to a second cell having a second available bandwidth, the second bias greater than the first bias, the second available bandwidth larger than the first available bandwidth, a greater bias indicating a larger portion of bandwidth to be allocated;

establishing a resource allocation for each cell in accordance with the bias for the each cell if there is an assignment of a bias for each cell that is operable to maintain the link, establishing the resource allocation further comprising repeating the following for each cell of the set of cells;

weighting the bandwidth of the cell according to the bias for the cell;

accepting a connection for the mobile device even if there is no resource allocation for one cell of the set of cells that is operable to maintain the wireless link; and

rejecting a connection for the mobile device if there is no assignment of a bias for each cell that is operable to maintain the wireless link.