Apparatus and method for multimode device handover

• US 9,258,754 B2
• Filed: 03/11/2013
• Issued: 02/09/2016
• Est. Priority Date: 04/15/2010
• Status: Active Grant

• Current Assignee: Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• Original Assignee: Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• Inventors: Pawar, Hemanth Balaji, Sitaram, Krishna D., Vivanco, Daniel
• Primary Examiner(s): NGUYEN, STEVEN H D
• Application Number:
  US13/793,122
• Publication Number:
  US 20140024373A1
• Time in Patent Office: 1,065 Days
• US Class Current: 1/1
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data

Abstract

Systems and methods of operating multimode 3G/4G communications devices in an overlapping 3G/4G coverage area (e.g., WiMAX or LTE/CDMA EvDO) include determining if a number associated with temporarily-disabled sectors of an available sector set of the multimode device while the device is operational with a 3G base station is at least equal to a threshold number. If the number is at least equal to the threshold number, a scan for a sector in the 4G network to handover the operation of the multimode device from the 3G base station associated with the 3G coverage to a 4G base station associated with the 4G coverage is initiated. A scan for a fixed period of time for a new available sector in the 3G network to be added in the available sector set may be initiated; and, if a new available sector is added to the sector set, it may be redetermined if the number associated with the temporarily-disabled sectors is at least equal to the threshold number, before initiating the scan for a sector in the 4G network.

Claims

1. A method to operate a multimode third generation (3G) and fourth generation (4G) communications device capable of operating in either a 4G network or a 3G network when in an area with overlapping 3G and 4G coverage, the method comprising:

based on an assessment that a number associated with temporarily-disabled sectors of an available sector set of the multimode device is at least equal to a threshold number, scanning, using a processor, for a new available sector in the 3G network;

if, upon scanning, the new available sector is identified, reassessing, using the processor, whether the number is at least equal to the threshold number; and

if, upon scanning, the new available sector is not identified initiating, using the processor, a scan for a sector in the 4G network to transfer communications operational at the multimode device from a 3G base station associated to a 4G base station

wherein the available sector set of the multimode device is stored in a memory operatively coupled to the processor, while the multimode device is operational with the 3G base station.

2. The method of claim 1, wherein the 4G base station provides data rate at least equal to the data rate provided by the 3G base station.

3. The method of claim 1, wherein the number associated with the temporarily-disabled sectors is a ratio of a number of temporarily-disabled sectors of the available sector set to the total number of sectors in the available sector set.

4. The method of claim 1, wherein the multimode device comprises a dual-mode CDMA/EvDO-LTE device.

5. The method of claim 1, wherein the 3G base station comprises a CDMA/EvDO base station.

6. The method of claim 1, wherein said scanning is performed for a certain fixed time period, and the new available sector is added in the available sector set.

7. The method of claim 1, wherein the 4G base station comprises an LTE base station.

8. The method of claim 1, wherein the temporarily-disabled sectors are disabled by the 3G base station by enabling Data Rate Control Lock (DRCLock).

9. A multimode communications apparatus capable of operating in either a 3G network or a 4G network when in an area with overlapping 3G and 4G coverage, the apparatus comprising:

a 3G transceiver configured to transmit and receive information over a 3G network;

a 4G transceiver configured to selectively transmit and receive data over a 4G network;

a memory device configured to store an available sector set associated with the 3G transceiver, while the apparatus is in communication with a 3G base station in the 3G network; and

a processor operatively coupled to the memory device, the 3G transceiver and the 4G transceiver, wherein the processor is configured to;

based on an assessment that a number associated with temporarily-disabled sectors of an available sector set of the multimode device is at least equal to a threshold number, scan for a new available sector in the 3G network,

if, upon scanning, the new available sector is identified, reassess whether the number is at least equal to the threshold number, and

if, upon scanning, the new available sector is not identified, initiate a scan for a sector in the 4G network to transfer communications operational at the multimode apparatus from the 3G base station associated to a 4G base station.

10. The apparatus of claim 9, wherein the number associated with the temporarily-disabled sectors is a ratio of a number of temporarily-disabled sectors of the available sector set to the total number of sectors in the available sector set.

11. The apparatus of claim 9, wherein the multimode apparatus is configured as a dual-mode CDMA/EvDO-LTE device.

12. The apparatus of claim 9, wherein the 3G base station comprises a CDMA/EvDO base station.

13. The apparatus of claim 9, wherein the 4G base station comprises an LTE base station.

14. The apparatus of claim 9, wherein the processor is configured to scan for a certain fixed time period, and add the new available sector to the available sector set.

15. A non-transitory computer-readable medium comprising computer readable code physically embodied thereon which, when executed by a processor arranged in a multimode third generation (3G) and fourth generation (4G) communications device capable of operating in either a 4G network or a 3G network when in an area with overlapping 3G and 4G coverage, causes the processor to carry out operations comprising:

based on an assessment that a number associated with temporarily-disabled sectors of an available sector set of the multimode device is at least equal to a threshold number, scanning for a new available sector in the 3G network;

if, upon scanning, the new available sector is identified, reassessing whether the number is at least equal to the threshold number; and

if, upon scanning, the new available sector is not identified, initiating a scan for a sector in the 4G network to transfer communications operational at the multimode apparatus from a 3G base station associated to a 4G base station,

wherein the available sector set of the multimode device is stored in a memory operatively coupled to the processor, while the multimode device is operational with the 3G base station.

16. The computer-readable medium of claim 15, wherein the number associated with the temporarily-disabled sectors is a ratio of a number of temporarily-disabled sectors of the available sector set to the total number of sectors in the available sector set.

17. The computer-readable medium of claim 15, wherein the multimode device comprises a dual-mode CDMA/EvDO-LTE device.

18. The computer-readable medium of claim 15, wherein the 3G base station comprises a CDMA/EvDO base station.

19. The computer-readable medium of claim 15, wherein the 4G base station comprises an LTE base station.

20. The computer-readable medium of claim 15, wherein said scanning is performed for a certain fixed time period, and the new available sector is added to the available sector set.