System and method for multimode device handover

• US 8,285,291 B2
• Filed: 02/02/2010
• Issued: 10/09/2012
• 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: Pawar, Hemanth Balaji, Tiwari, Swati, Sitaram, Krishna, Jung, Jong-Hak, Dinan, Esmail H.
• Primary Examiner(s): Cai, Wayne
• Assistant Examiner(s): Huynh, Chuck
• Application Number:
  US12/698,384
• Publication Number:
  US 20110189997A1
• Time in Patent Office: 980 Days
• Field of Search: 455/443, 455/436, 455/452.2, 455/448, 455/437, 455/438, 455/439, 455/440, 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:

determining a loading condition of each of a 4G base station and a 3G base station associated with the overlapping 3G and 4G coverage area;

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

evaluating the comparison result 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 a 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 a 3G base station associated with the 3G coverage.

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

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

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

5. The method of claim 1, further comprising:

responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the user priority is a lowest user priority and the MIMO mode comprises spatial multiplexing, assigning the dual mode communications device to the 4G network.

6. The method of claim 5, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

7. The method of claim 5, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

8. The method of claim 1, further comprising:

responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the user priority is a lowest user priority and the MIMO mode comprises space-time-coding, assigning the dual mode communications device to the 3G network.

9. The method of claim 8, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

10. The method of claim 8, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

11. The method of claim 1, further comprising:

responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate a user priority; and

if the user priority is greater than a lowest user priority, assigning the dual mode communications device to the 4G network.

12. The method of claim 1, further comprising:

responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the user priority is less than a highest user priority and the MIMO mode comprises spatial multiplexing, assigning the dual mode communications device to the 4G network.

13. The method of claim 12, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

14. The method of claim 12, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

15. The method of claim 1, further comprising:

responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the user priority is less than a highest user priority and the MIMO mode comprises space-time-coding, assigning the dual mode communications device to the 3G network.

16. The method of claim 15, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

17. The method of claim 15, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

18. The method of claim 1, further comprising:

responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate a user priority; and

if the user priority is a highest user priority, assigning the dual mode communications device to the 4G network.

19. The method of claim 1, further comprising:

responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the application category is a lowest application category and the MIMO mode comprises spatial multiplexing, assigning the dual mode communications device to the 4G network.

20. The method of claim 19, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

21. The method of claim 19, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

22. The method of claim 1, further comprising:

responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the application category is a lowest application category and the MIMO mode comprises space-time-coding, assigning the dual mode communications device to the 3G network.

23. The method of claim 22, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

24. The method of claim 22, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

25. The method of claim 1, further comprising:

responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate an application category; and

if the application category is greater than a lowest user priority, assigning the dual mode communications device to the 4G network.

26. The method of claim 1, further comprising:

responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the application category is less than a highest application category and the MIMO mode comprises spatial multiplexing, assigning the dual mode communications device to the 4G network.

27. The method of claim 26, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

28. The method of claim 26, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

29. The method of claim 1, further comprising:

responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network; and

if the application category is less than a highest application category and the MIMO mode comprises space-time-coding, assigning the dual mode communications device to the 3G network.

30. The method of claim 29, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

31. The method of claim 29, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

32. The method of claim 1, further comprising:

responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, using the processor to evaluate an application category; and

if the application category is a highest user priority, assigning the dual mode communications device to the 4G network.

33. 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;

wherein the processor evaluates the comparison result to determine which of the 4G and 3G networks allows a higher data throughput,

wherein, if the 4G network allows the higher data throughput, the processor enables control signals that transfer or maintain communication of the dual mode communications device with a 4G base station associated with the 4G coverage, and

wherein, if the 3G network allows the higher data throughput, the processor enables different control signals that transfer communication of the dual mode communications device to a 3G base station associated with the 3G coverage.

34. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the user priority is a lowest user priority and the MIMO mode comprises spatial multiplexing, the processor assigns the dual mode communications device to the 4G network.

35. The apparatus of claim 34, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

36. The apparatus of claim 34, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

37. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the user priority is a lowest user priority and the MIMO mode comprises space-time-coding, the processor assigns the dual mode communications device to the 3G network.

38. The apparatus of claim 37, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

39. The apparatus of claim 37, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

40. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate a user priority;

and

if the user priority is greater than a lowest user priority, the processor assigns the dual mode communications device to the 4G network.

41. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the user priority is less than a highest user priority and the MIMO mode comprises spatial multiplexing, the processor assigns the dual mode communications device to the 4G network.

42. The apparatus of claim 41, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

43. The apparatus of claim 41, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

44. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate a user priority and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the user priority is less than a highest user priority and the MIMO mode comprises space-time-coding, the processor assigns the dual mode communications device to the 3G network.

45. The apparatus of claim 44, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

46. The apparatus of claim 44, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

47. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate a user priority;

and

if the user priority is a highest user priority, the processor assigns the dual mode communications device to the 4G network.

48. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the application category is a lowest application category and the MIMO mode comprises spatial multiplexing, the processor assigns the dual mode communications device to the 4G network.

49. The apparatus of claim 48, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

50. The apparatus of claim 48, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

51. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the application category is a lowest application category and the MIMO mode comprises space-time-coding, the processor assigns the dual mode communications device to the 3G network.

52. The apparatus of claim 51, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

53. The apparatus of claim 51, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

54. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is intermediately loaded at a load value greater than the first user determined load factor and less than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate an application category;

and

if the application category is greater than a lowest user priority, the processor assigns the dual mode communications device to the 4G network.

55. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the application category is less than a highest application category and the MIMO mode comprises spatial multiplexing, the processor assigns the dual mode communications device to the 4G network.

56. The apparatus of claim 55, wherein the MIMO mode comprising spatial multiplexing is WiMAX MIMO-B.

57. The apparatus of claim 55, wherein the MIMO mode comprising spatial multiplexing is LTE MU-MIMO.

58. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor greater than the first user determined load factor, the processor is further configured to evaluate an application category and a multi-input-multi-output (MIMO) mode associated with the 4G network;

and

if the application category is less than a highest application category and the MIMO mode comprises space-time-coding, the processor assigns the dual mode communications device to the 3G network.

59. The apparatus of claim 58, wherein the MIMO mode comprising space-time-coding is WiMAX MIMO-A.

60. The apparatus of claim 58, wherein the MIMO mode comprising space-time-coding is an LTE downlink transmit diversity mode.

61. The apparatus of claim 33, wherein, responsive to a determination that the 4G network is heavily loaded at a load value greater than a second user determined load factor that is greater than the first user determined load factor, the processor is further configured to evaluate an application category;

and

if the application category is a highest user priority, the processor assigns the dual mode communications device to the 4G network.

62. A 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 functions of:

determining a loading condition of each of a 4G base station and a 3G base station associated with an overlapping 3G and 4G coverage area;

responsive to a determination that each of the 3G and 4G base stations are loaded less than a first user inputted load factor, using a processor 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 a memory;

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

handing off the dual mode communications device to a 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 an 3G base station associated with the EvDO coverage.

63. A method of over-the-air provisioning of program functionality and data stored in a multimode third generation (3G) and fourth generation (4G) communications device capable of

sending program instruction updates to the multimode device over a communications link operating in either a 4G network or a 3G network mode, the method comprising:

from a base station (BS), wherein the program instruction updates include computer code that, when executed by a processor;

determines a loading condition of each of a 4G base station and a 3G base station associated with an overlapping 3G and 4G coverage area,

compares 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 if each of the 3G and 4G base stations are loaded less than a first user inputted load factor,

determines which of the 3G and 4G networks allows a higher data throughput,

causes the dual mode communications device to transfer to a 4G base station associated with the 4G coverage if the 4G network allows the higher data throughput or causes the dual mode communications device to transfer to an 3G base station associated with the 3G coverage if the 3G network allows the higher data throughput;

sending data updates to the dual-mode device over the communications link from the BS, wherein the data updates comprise 4G Channel Quality Indicators (CQI) mapped to one or more corresponding 3G Data Rate Control (DRC) indices; and

storing the program instruction updates and the data updates in a memory in the dual mode communications device.