System and method for multimode device handover

• US 8,805,379 B2
• Filed: 10/08/2012
• Issued: 08/12/2014
• Est. Priority Date: 02/02/2010
• Status: Active Grant

• Current Assignee: Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• Original Assignee: Clearwire Ip Holdings LLC (Deutsche Telekom AG)
• Inventors: Tiwari, Swati, Pawar, Hemanth Balaji, Dinan, Esmail H., Sitaram, Krishna, Jung, Jong-Hak
• Primary Examiner(s): Cai, Wayne
• Assistant Examiner(s): Huynh, Chuck
• Application Number:
  US13/647,079
• Publication Number:
  US 20130059591A1
• Time in Patent Office: 673 Days
• Field of Search: 455/443, 455/448, 455/437, 455/438, 455/439, 455/440, 455/452.2, 455/453, 370/331
• US Class Current: 455/443
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0689 using different transmission schemes, at least one of them being a diversity transmission scheme
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 36/26 by agreed or negotiated communication parameters
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

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 a loading condition of the 3G and 4G base stations. If the 3G and 4G base stations are lightly loaded, one or more 4G Channel Quality Indicators (CQI) are compared with one or more corresponding 3G Data Rate Control (DRC) indices to determine which of the 3G and 4G networks allows a higher data throughput. The dual mode communications device is handed off to a 4G base station associated with the 4G coverage if the 4G network allows the higher data throughput; otherwise, the dual mode communications device is handed off to a 3G base station. User priorities, application categories, and/or MIMO and diversity modes may be used to determine handoff if the base stations are more than lightly loaded.

Claims

1. A method of operating 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:

responsive to a determination that each of a 3G base station and a 4G base station associated with an overlapping 3G and 4G coverage area are loaded less than a first user determined load factor, comparing, using a processor, one or more 4G Channel Quality Indicators (CQI) with one or more corresponding 3 GData Rate Control (DRC) indices stored in corresponding mapping tables in a memory; and

based on a result of said comparing, determining a handoff of the dual mode communications device to a 3G base station associated with the 3G coverage or to a 4G base station associated with the 4G coverage.

2. The method of claim 1, determining a loading condition of each of the 4G base station and the 3G base station associated with the overlapping 3G and 4G coverage area.

3. The method of claim 1, wherein said determining a handoff comprises:

evaluating the result of said comparing with the processor to determine which of the 3G and 4G networks allows a higher data throughput;

handing off the dual mode communications device to the 4G base station associated with the 4G coverage if the 4G network allows the higher data throughput; and

otherwise, handing off the dual mode communications device to the 3G base station associated with the 3G coverage.

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

5. The method of claim 1, wherein the 4G base station comprises a WiMAX base station.

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

7. A multimode third generation (3G) and fourth generation (4G) 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 processor operatively coupled to the 3G transceiver and the 4G transceiver and which is configured to determine a loading condition of each of a 3G base station and a 4G base station associated with the overlapping 3G and 4G coverage area; and

a memory device operatively coupled to the processor;

wherein, responsive to a determination by the processor that each of the 3G and 4G base stations are loaded less than a first user determined load factor, the processor is configured to;

compare one or more 4G Channel Quality Indicators (CQI) with one or more corresponding 3G Data Rate Control (DRC) indices stored in corresponding mapping tables in the memory; and

based on a result of the comparison, determine a handoff of the dual mode communications device to a 3G base station associated with the 3G coverage or to a 4G base station associated with the 4G coverage.

8. The apparatus of claim 7, wherein, to determine a handoff, the processor is configured to:

evaluate a result a comparison of the one or more 4G CQls with the one or more corresponding 3G DRCs to determine which of the 3G and 4G networks allows a higher data throughput; and

hand off the dual mode communications device to the 4G base station associated with the 4G coverage if the 4G network allows the higher data throughput than the 3G network, otherwise, hand off the dual mode communications device to the 3G base station associated with the 3G coverage.

9. The apparatus of claim 7, wherein the 3G base station comprises a CDMA/EvDO base station.

10. The apparatus of claim 7, wherein the 4G base station comprises a WiMAX base station.

11. The apparatus of claim 7, wherein the 4G base station comprises an LTE base station.

12. 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 mode causes the processor to carry out the operations of:

responsive to a determination that each of a 3G base station and a 4G base station associated with an overlapping 3G and 4G coverage area are loaded less than a first user determined load factor, comparing one or more 4G Channel Quality Indicators (CQI) with one or more corresponding 3G Data Rate Control (DRC) indices stored in corresponding mapping tables in a memory; and

based on a result of said comparing, determining a handoff of the dual mode communications device to a 3G base station associated with the 3G coverage or to a 4G base station associated with the 4G coverage.

13. The medium of claim 12, wherein the operations further comprise determining a loading condition of each of the 4G base station and the 3G base station associated with the overlapping 3G and 4G coverage area.

14. The medium of claim 12, wherein said determining a handoff comprises:

evaluating the result of said comparing with the processor to determine which of the 3G and 4G networks allows a higher data throughput; and

handing off the dual mode communications device to the 4G base station associated with the 4G coverage if the 4G network allows the higher data throughput, otherwise, handing off the dual mode communications device to the 3G base station associated with the 3G coverage.

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

16. The medium of claim 12, wherein the 4G base station comprises a WiMAX base station.

17. The medium of claim 12, wherein the 4G base station comprises an LTE base station.