METHODS AND APPARATUS FOR IOT OPERATION IN UNLICENSED SPECTRUM

• US 20180020360A1
• Filed: 06/01/2017
• Published: 01/18/2018
• Est. Priority Date: 07/15/2016
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: YERRAMALLI, Srinivas, RICO ALVARINO, Alberto, XU, Hao, CHEN, Wanshi, MONTOJO, Juan, WEI, Yongbin, GAAL, Peter
• Granted Patent: US 11,102,779 B2
• Time in Patent Office: Days
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/7156 Arrangements for sequence synchronisation
• CPC Class Codes: H04B 2001/71563 Acquisition
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/2634 Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0012 Hopping in multicarrier systems for frequency hopping in spread spectrum systems H04B1/713
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]

Abstract

Various aspects of utilizing narrowband internet of things (NB IOT) communication are still under development. According to an aspect of the disclosure, the apparatus may be a user equipment (UE) for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation. The UE performs a synchronization with a base station via at least one of a licensed spectrum or the unlicensed spectrum. The UE communicates with the base station based on the synchronization.

Claims

1. A method of wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum by a user equipment (UE) using frequency hopping and digital modulation, comprising:

performing a synchronization with a base station via at least one of a licensed spectrum or the unlicensed spectrum; and

communicating with the base station based on the synchronization.

2. The method of claim 1, wherein the performing the synchronization comprises:

camping on a licensed carrier in the licensed spectrum in an RRC connected mode; and

performing the synchronization on the licensed carrier in the licensed spectrum, and

wherein the method further comprises tuning to an NB IOT carrier operating in the unlicensed spectrum to communicate data using the NB IOT carrier in the unlicensed spectrum.

3. The method of claim 2, wherein the NB IOT carrier in the unlicensed spectrum is carrier-aggregation synchronized to the licensed carrier.

4. The method of claim 2, further comprising:

receiving hopping pattern information of a plurality of hopping carriers in the unlicensed spectrum, wherein the tuning to the NB IOT carrier is based on the hopping pattern information,

wherein the hopping pattern information includes at least one of;

a number of the plurality of hopping carriers, information for generating a hopping pattern, subframe number to start hopping, dwell time information per channel, or power restraints on the unlicensed carrier.

5. The method of claim 2, further comprising:

retuning to the licensed carrier after communicating the data via the NB IOT carrier in the unlicensed spectrum; and

performing another synchronization on the licensed carrier in the licensed spectrum.

6. The method of claim 1, wherein the performing the synchronization comprises:

utilizing a downlink channel to receive a downlink communication in a licensed spectrum; and

utilizing an uplink channel to transmit an uplink communication in the unlicensed spectrum,

wherein the method further comprises;

receiving at least one of a downlink grant or a uplink grant via the downlink communication in the licensed spectrum; and

transmitting the uplink communication in the unlicensed spectrum based on the uplink grant if the uplink grant is received; and

receiving the downlink communication in the licensed spectrum based on the downlink grant if the downlink grant is received.

7. The method of claim 1, wherein the performing the synchronization comprises:

performing the synchronization in the unlicensed spectrum, and

wherein the method further comprises switching to a different carrier before the synchronization in the unlicensed spectrum upon expiration of a dwell time on a current carrier.

8. The method of claim 7, wherein the different carrier includes one or more carriers corresponding to one or more hopping frequencies that are aligned with a channel raster in the unlicensed spectrum.

9. The method of claim 8, wherein the performing the synchronization comprises at least one of:

utilizing the channel raster to be less than 100 KHz, or

setting a hopping bandwidth based on a hopping bandwidth indication from the base station.

10. The method of claim 7, further comprising:

before switching to the different carrier upon expiration of the dwell time, obtaining at least one of;

a frequency hopping indication indicating whether frequency hopping exists,

an end indication of dwell time on a current hopping frequency, or

a next hopping frequency.

11. The method of claim 7, further comprising:

performing a cell search by searching a plurality of frequencies in the unlicensed spectrum; and

selecting a frequency of the plurality of frequencies based on a channel raster, wherein the selected frequency has a highest signal strength of the plurality of frequencies,

wherein the synchronization is performed using a carrier corresponding to the selected frequency in the unlicensed spectrum.

12. The method of claim 11, further comprising:

if a same carrier is detected in two or more frequencies of the plurality of frequencies during the cell search, refraining from communicating via at least one of the two or more frequencies of the plurality of frequencies.

13. The method of claim 7, further comprising:

receiving a hopping pattern change indication indicating that a hopping pattern of a plurality of frequencies in the unlicensed spectrum is scheduled to change;

acquiring hopping information including a new hopping pattern based on the hopping pattern change indication; and

selecting a frequency of the plurality of frequencies in the unlicensed spectrum based on the new hopping pattern,

wherein the synchronization is performed using a carrier corresponding to the selected frequency in the unlicensed spectrum.

14. The method of claim 13, wherein the acquiring the hopping information comprises at least one of:

if the hopping information is included in at least one of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), or a narrowband physical broadcast channel (NPBCH), acquiring the at least one of the NPSS, the NSSS, and the NPBCH within a dwell time;

if the hopping information is included in a system information block (SIB), acquiring the SIB within the dwell time;

or

if the hopping information is provided via radio resource control (RRC), performing at least one of RRC connection setup or RRC connection re-establishment within the dwell time.

15. The method of claim 7, further comprising:

obtaining an end indication of a dwell time on a current hopping frequency corresponding to the current carrier, wherein the obtaining the end indication comprises at least one of;

receiving the end indication in a first three symbols in a subframe carrying a narrowband primary synchronization signal (NPSS) to indicate a last NPSS transmission before hopping from the current hopping frequency to another frequency, or

receiving the end indication in a first three symbols in a subframe carrying a narrowband secondary synchronization signal (NSSS) to indicate a last NSSS transmission before hopping from the current hopping frequency to the another frequency.

16. The method of claim 7, wherein the frequency hopping is non-uniform.

17. The method of claim 16, wherein the UE hops to an anchor frequency more often than to one or more non-anchor frequencies.

18. The method of claim 16, wherein the UE hops to one frequency more often than to another frequency based on signal interference.

19. A method of wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum by a base station using frequency hopping and digital modulation, comprising:

performing a synchronization with a user equipment (UE) via at least one of a licensed spectrum or the unlicensed spectrum; and

communicating with the UE based on the synchronization.

20. The method of claim 19, wherein the performing the synchronization comprises performing the synchronization in the licensed spectrum, and

wherein the method further comprises:

tuning to an NB IOT carrier operating in the unlicensed spectrum; and

configuring the UE to tune to the NB IOT carrier operating in the unlicensed spectrum to communicate data using the NB IOT carrier in the unlicensed spectrum.

21. The method of claim 20, wherein the NB IOT carrier in the unlicensed spectrum is carrier-aggregation synchronized to a licensed carrier in the licensed spectrum.

22. The method of claim 20, further comprising:

transmitting hopping pattern information of a plurality of hopping carriers in the unlicensed spectrum to the UE to configure the UE with the hopping pattern information,

wherein the hopping pattern information includes at least one of;

a number of the plurality of hopping carriers, information for generating a hopping pattern, subframe number to start hopping, dwell time information per channel, or power restraints on the unlicensed carrier.

23. The method of claim 20, further comprising:

configuring the UE to retune to a licensed carrier in the licensed spectrum to perform another synchronization after communicating the data via the NB IOT carrier in the unlicensed spectrum; and

performing the another synchronization on the licensed carrier in the licensed spectrum.

24. The method of claim 19, wherein the performing the synchronization comprises:

configuring a downlink channel to transmit a downlink communication in the licensed spectrum; and

configuring an uplink channel to receive an uplink communication in the unlicensed spectrum,

wherein the method further comprises;

transmitting at least one of a downlink grant or a uplink grant via the downlink communication in the licensed spectrum;

receiving the uplink communication in the unlicensed spectrum if the uplink grant is transmitted; and

transmitting the downlink communication in the licensed spectrum if the downlink grant is transmitted.

25. The method of claim 19, wherein the performing the synchronization comprises:

performing the synchronization in the unlicensed spectrum, and

wherein the method further comprises switching to a different carrier for the synchronization in the unlicensed spectrum upon expiration of a dwell time on a current carrier.

26. The method of claim 25, wherein the different carrier includes one or more carriers corresponding to one or more hopping frequencies that are aligned with a channel raster in the unlicensed spectrum.

27. The method of claim 26, wherein the performing the synchronization comprises at least one of:

utilizing the channel raster that is less than 100 KHz, or

setting a hopping bandwidth based on a hopping bandwidth indication.

28. The method of claim 25, further comprising:

before switching to the different carrier upon expiration of the dwell time, transmitting at least one of;

a frequency hopping indication indicating whether frequency hopping exists,

an end indication of dwell time on a current hopping frequency, or

a next hopping frequency.

29. The method of claim 25, further comprising:

transmitting a hopping pattern change indication indicating that a hopping pattern of a plurality of frequencies is scheduled to change; and

transmitting hopping information including a new hopping pattern based on the hopping pattern change indication.

30. The method of claim 25, wherein the transmitting the hopping information comprises at least one of:

transmitting the hopping information via at least one of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), or a narrowband physical broadcast channel (NPBCH) within a dwell time,

transmitting the hopping information via a system information block (SIB) within the dwell time, or

if the hopping information is provided via radio resource control (RRC), performing at least one of RRC connection setup or RRC connection re-establishment within the dwell time.

31. The method of claim 25, further comprising:

transmitting an end indication of a dwell time on a current hopping frequency corresponding to the current carrier, wherein the transmitting the end indication comprises at least one of;

providing the end indication in a first three symbols in a subframe carrying a narrowband primary synchronization signal (NPSS) to indicate a last NPSS transmission before hopping from the current hopping frequency to another frequency, or

providing the end indication in a first three symbols in a subframe carrying a narrowband secondary synchronization signal (NSSS) to indicate a last NSSS transmission before hopping from the current hopping frequency to the another frequency.

32. The method of claim 25, wherein the frequency hopping is non-uniform.

33. The method of claim 32, wherein the base station hops to an anchor frequency more often than to one or more non-anchor frequencies.

34. The method of claim 32, wherein the base station hops to one frequency more often than to another frequency based on signal interference.

35. A user equipment (UE) for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation, comprising:

means for performing a synchronization with a base station via at least one of a licensed spectrum or the unlicensed spectrum; and

means for communicating with the base station based on the synchronization.

36. The UE of claim 35, wherein the means for performing the synchronization is configured to:

camp on a licensed carrier in the licensed spectrum in an RRC connected mode; and

perform the synchronization on the licensed carrier in the licensed spectrum, and

wherein the UE further comprises means for tuning to an NB IOT carrier operating in the unlicensed spectrum to communicate data using the NB IOT carrier in the unlicensed spectrum.

37. The UE of claim 36, wherein the NB IOT carrier in the unlicensed spectrum is carrier-aggregation synchronized to the licensed carrier.

38. The UE of claim 36, further comprising:

means for receiving hopping pattern information of a plurality of hopping carriers in the unlicensed spectrum, wherein the tuning to the NB IOT carrier is based on the hopping patterns information,

wherein the hopping pattern information includes at least one of;

a number of the plurality of hopping carriers, information for generating a hopping pattern, subframe number to start hopping, dwell time information per channel, or power restraints on the unlicensed carrier.

39. The UE of claim 36, further comprising:

means for retuning to the licensed carrier after communicating the data via the NB IOT carrier in the unlicensed spectrum; and

means for performing another synchronization on the licensed carrier in the licensed spectrum.

40. The UE of claim 35, wherein the means for performing the synchronization is configured to:

utilize a downlink channel to receive downlink communication in a licensed spectrum; and

utilize an uplink channel to transmit uplink communication in the unlicensed spectrum,

wherein the UE further comprises;

means for receiving at least one of a downlink grant or a uplink grant via downlink communication in the licensed spectrum; and

means for transmitting the uplink communication in the unlicensed spectrum based on the uplink grant if the uplink grant is received; and

means for receiving the downlink communication in the licensed spectrum based on the downlink grant if the downlink grant is received.

41. The UE of claim 35, wherein the means for performing the synchronization is configured to:

perform the synchronization in the unlicensed spectrum, and

wherein the UE further comprises means for switching to a different carrier for the synchronization in the unlicensed spectrum upon expiration of a dwell time on a current carrier.

42. The UE of claim 41, wherein the different carrier includes one or more carriers corresponding to one or more hopping frequencies that are aligned with a channel raster in the unlicensed spectrum.

43. The UE of claim 42, wherein the means for performing the synchronization is configured to perform at least one of:

utilizing the channel raster to be less than 100 KHz, or

setting a hopping bandwidth based on a hopping bandwidth indication from the base station.

44. The UE of claim 41, further comprising:

means for obtaining, before switching to the different carrier upon expiration of the dwell time, at least one of;

a frequency hopping indication indicating whether frequency hopping exists,

an end indication of dwell time on a current hopping frequency, or

a next hopping frequency.

45. The UE of claim 41, further comprising:

means for performing a cell search by searching a plurality of frequencies in the unlicensed spectrum; and

means for selecting a frequency of the plurality of frequencies based on a channel raster, wherein the selected frequency has a highest signal strength of the plurality of frequencies,

wherein the synchronization is performed using a carrier corresponding to the selected frequency in the unlicensed spectrum.

46. The UE of claim 45, further comprising:

means for refraining from communicating via at least one of two or more frequencies of the plurality of frequencies if a same carrier is detected in the two or more frequencies of the plurality of frequencies during the cell search.

47. The UE of claim 41, further comprising:

means for receiving hopping pattern change indication indicating that a hopping pattern of a plurality of frequencies in the unlicensed spectrum is scheduled to change;

means for acquiring hopping information including a new hopping pattern based on the hopping pattern change indication; and

means for selecting a frequency out of a plurality of frequencies in the unlicensed spectrum based on the new hopping pattern,

wherein the synchronization is performed using a carrier corresponding to the selected frequency in the unlicensed spectrum.

48. The UE of claim 47, wherein the means for acquiring the hopping information is configured to perform at least one of:

if the hopping information is included in at least one of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), or a narrowband physical broadcast channel (NPBCH), acquiring the at least one of the NPSS, the NSSS, and the NPBCH within a dwell time;

if the hopping information is included in a system information block (SIB), acquiring the SIB within a dwell time;

or

if the hopping information is provided via radio resource control (RRC), performing at least one of RRC connection setup or RRC connection re-establishment within a dwell time.

49. The UE of claim 41, further comprising:

means for obtaining an end indication of a dwell time on a current hopping frequency corresponding to the current carrier, wherein the means for obtaining the end indication is configured to perform at least one of;

receiving the end indication in a first three symbols in a subframe carrying a narrowband primary synchronization signal (NPSS) to indicate a last NPSS transmission before hopping from the current hopping frequency to another frequency, or

receiving the end indication in a first three symbols in a subframe carrying a narrowband secondary synchronization signal (NSSS) to indicate a last NSSS transmission before hopping from the current hopping frequency to the another frequency.

50. The UE of claim 41, wherein the frequency hopping is non-uniform.

51. The UE of claim 50, wherein the UE hops to an anchor frequency more often than to one or more non-anchor frequencies.

52. The UE of claim 50, wherein the UE hops to one frequency more often than to another frequency based on signal interference.

53. A base station for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation, comprising:

means for performing a synchronization with a user equipment (UE) via at least one of a licensed spectrum or the unlicensed spectrum; and

means for communicating with the UE based on the synchronization.

54. The base station of claim 53, wherein the means for performing the synchronization is configured to perform the synchronization in the licensed spectrum, and

wherein the base station further comprises:

means for tuning to an NB IOT carrier operating in the unlicensed spectrum; and

means for configuring the UE to tune to the NB IOT carrier operating in the unlicensed spectrum to communicate data using the NB IOT carrier in the unlicensed spectrum.

55. The base station of claim 54, wherein the NB IOT carrier in the unlicensed spectrum is carrier-aggregation synchronized to a licensed carrier in the licensed spectrum.

56. The base station of claim 54, further comprising:

means for transmitting hopping pattern information of a plurality of hopping carriers in the unlicensed spectrum to the UE to configure the UE with the hopping pattern information,

wherein the hopping pattern information includes at least one of;

a number of the plurality of hopping carriers, information for generating a hopping pattern, subframe number to start hopping, dwell time information per channel, or power restraints on the unlicensed carrier.

57. The base station of claim 54, further comprising:

means for configuring the UE to retune to a licensed carrier in the licensed spectrum to perform another synchronization after communicating the data via the NB IOT carrier in the unlicensed spectrum; and

means for performing the another synchronization on the licensed carrier in the licensed spectrum.

58. The base station of claim 53, wherein the means for performing the synchronization is configured to:

configure a downlink channel to transmit a downlink communication in a licensed spectrum; and

configure an uplink channel to receive an uplink communication in the unlicensed spectrum,

wherein the base station further comprises;

means for transmitting at least one of a downlink grant or a uplink grant via downlink communication in the licensed spectrum;

means for receiving the uplink communication in the unlicensed spectrum if the uplink grant is transmitted; and

means for transmitting the downlink communication in the licensed spectrum if the downlink grant is transmitted.

59. The base station of claim 53, wherein the means for performing the synchronization is configured to:

perform the synchronization in the unlicensed spectrum, and

wherein the base station further comprises means for switching to a different carrier for the synchronization in the unlicensed spectrum upon expiration of a dwell time on a current carrier.

60. The base station of claim 59, wherein the different carrier includes one or more carriers corresponding to one or more hopping frequencies that are aligned with a channel raster in the unlicensed spectrum.

61. The base station of claim 60, wherein the means for configuring the synchronization is configured to perform at least one of:

utilizing the channel raster that is less than 100 KHz, or

setting a hopping bandwidth based on a hopping bandwidth indication.

62. The base station of claim 59, further comprising:

means for transmitting, before switching to the different carrier upon expiration of the dwell time, at least one of;

a frequency hopping indication indicating whether frequency hopping exists,

an end indication of dwell time on a current hopping frequency, or

a next hopping frequency.

63. The base station of claim 59, further comprising:

means for transmitting a hopping pattern change indication indicating that a hopping pattern of a plurality of frequencies is scheduled to change; and

means for transmitting hopping information including a new hopping pattern based on the hopping pattern change indication.

64. The base station of claim 59, wherein the means for transmitting the hopping information is configured to perform at least one of:

transmitting the hopping information via at least one of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), or a narrowband physical broadcast channel (NPBCH) within a dwell time,

transmitting the hopping information via a system information block (SIB) within the dwell time, or

if the hopping information is provided via radio resource control (RRC), performing at least one of RRC connection setup or RRC connection re-establishment within the dwell time.

65. The base station of claim 59, further comprising:

means for transmitting an end indication of a dwell time on a current hopping frequency corresponding to the current carrier, wherein the means for transmitting the end indication is configured to perform at least one of;

providing the end indication in a first three symbols in a subframe carrying a narrowband primary synchronization signal (NPSS) to indicate a last NPSS transmission before hopping from the current hopping frequency to another frequency, or

providing the end indication in a first three symbols in a subframe carrying a narrowband secondary synchronization signal (NSSS) to indicate a last NSSS transmission before hopping from the current hopping frequency to the another frequency.

66. The base station of claim 59, wherein the frequency hopping is non-uniform.

67. The base station of claim 66, wherein the base station hops to an anchor frequency more often than to one or more non-anchor frequencies.

68. The base station of claim 66, wherein the base station hops to one frequency more often than to another frequency based on signal interference.

69. A user equipment (UE) for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation, comprising:

a memory; and

at least one processor coupled to the memory and configured to;

perform a synchronization with a base station via at least one of a licensed spectrum or the unlicensed spectrum; and

communicate with the base station based on the synchronization.

70. The UE of claim 69, wherein the at least one processor configured to perform the synchronization is configured to:

camp on a licensed carrier in the licensed spectrum in an RRC connected mode; and

perform the synchronization on the licensed carrier in the licensed spectrum, and

wherein the UE further comprises tuning to an NB IOT carrier operating in the unlicensed spectrum to communicate data using the NB IOT carrier in the unlicensed spectrum.

71. The UE of claim 70, wherein the NB IOT carrier in the unlicensed spectrum is carrier-aggregation synchronized to the licensed carrier.

72. The UE of claim 70, wherein the at least one processor is further configured to:

receive hopping pattern information of a plurality of hopping carriers in the unlicensed spectrum, wherein the tuning to the NB IOT carrier is based on the hopping pattern information,

wherein the hopping pattern information includes at least one of;

a number of the plurality of hopping carriers, information for generating a hopping pattern, subframe number to start hopping, dwell time information per channel, or power restraints on the unlicensed carrier.

73. The UE of claim 70, wherein the at least one processor is further configured to:

retune to the licensed carrier after communicating the data via the NB IOT carrier in the unlicensed spectrum; and

perform another synchronization on the licensed carrier in the licensed spectrum.

74. The UE of claim 69, wherein the at least one processor configured to perform the synchronization is configured to:

utilize a downlink channel to receive a downlink communication in a licensed spectrum; and

utilize an uplink channel to transmit an uplink communication in the unlicensed spectrum,

wherein the at least one processor is further configured to;

receive at least one of a downlink grant or a uplink grant via downlink communication in the licensed spectrum; and

transmit the uplink communication in the unlicensed spectrum based on the uplink grant if the uplink grant is received; and

receive the downlink communication in the licensed spectrum based on the downlink grant if the downlink grant is received.

75. The UE of claim 69, wherein the at least one processor configured to perform the synchronization is configured to:

perform the synchronization in the unlicensed spectrum, and

wherein the UE further comprises switching to a different carrier for the synchronization in the unlicensed spectrum upon expiration of a dwell time on a current carrier.

76. The UE of claim 75, wherein the different carrier includes one or more carriers corresponding to one or more hopping frequencies that are aligned with a channel raster in the unlicensed spectrum.

77. The UE of claim 76, wherein the at least one processor configured to perform the synchronization is configured to perform at least one of:

utilizing the channel raster to be less than 100 KHz, or

setting a hopping bandwidth based on a hopping bandwidth indication from the base station.

78. The UE of claim 75, wherein the at least one processor is further configured to:

before switching to the different carrier upon expiration of the dwell time, obtain at least one of;

a frequency hopping indication indicating whether frequency hopping exists,

an end indication of dwell time on a current hopping frequency, or

a next hopping frequency.

79. The UE of claim 75, wherein the at least one processor is further configured to:

perform a cell search by searching a plurality of frequencies in the unlicensed spectrum; and

select a frequency of the plurality of frequencies based on a channel raster, wherein the selected frequency has a highest signal strength of the plurality of frequencies,

wherein the synchronization is performed using a carrier corresponding to the selected frequency in the unlicensed spectrum.

80. The UE of claim 79, wherein the at least one processor is further configured to:

if a same carrier is detected in two or more frequencies of the plurality of frequencies during the cell search, refrain from communicating via at least one of the two or more frequencies of the plurality of frequencies.

81. The UE of claim 75, wherein the at least one processor is further configured to:

receive hopping pattern change indication indicating that a hopping pattern of a plurality of frequencies in the unlicensed spectrum is scheduled to change;

acquire hopping information including a new hopping pattern based on the hopping pattern change indication; and

select a frequency out of a plurality of frequencies in the unlicensed spectrum based on the new hopping pattern,

wherein the synchronization is performed using a carrier corresponding to the selected frequency in the unlicensed spectrum.

82. The UE of claim 81, wherein the at least one processor configured to acquire the hopping information is configured to perform at least one of:

if the hopping information is included in at least one of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), or a narrowband physical broadcast channel (NPBCH), acquiring the at least one of the NPSS, the NSSS, and the NPBCH within a dwell time;

if the hopping information is included in a system information block (SIB), acquiring the SIB within a dwell time;

or

if the hopping information is provided via radio resource control (RRC), performing at least one of RRC connection setup or RRC connection re-establishment within a dwell time.

83. The UE of claim 75, wherein the at least one processor is further configured to:

obtaining an end indication of a dwell time on a current hopping frequency corresponding to the current carrier, wherein the obtaining the end indication comprises at least one of;

receiving the end indication in a first three symbols in a subframe carrying a narrowband primary synchronization signal (NPSS) to indicate a last NPSS transmission before hopping from the current hopping frequency to another frequency, or

receiving the end indication in a first three symbols in a subframe carrying a narrowband secondary synchronization signal (NSSS) to indicate a last NSSS transmission before hopping from the current hopping frequency to the another frequency.

84. The UE of claim 75, wherein the frequency hopping is non-uniform.

85. The UE of claim 84, wherein the UE hops to an anchor frequency more often than to one or more non-anchor frequencies.

86. The UE of claim 84, wherein the UE hops to one frequency more often than to another frequency based on signal interference.

87. A base station for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation, comprising:

a memory;

at least one processor coupled to the memory and configured to;

perform a synchronization with a user equipment (UE) via at least one of a licensed spectrum or the unlicensed spectrum; and

communicate with the UE based on the synchronization.

88. The base station of claim 87, wherein the at least one processor configured to perform the synchronization is configured to perform the synchronization in the licensed spectrum, and

wherein the at least one processor is further configured to:

tune to an NB IOT carrier operating in the unlicensed spectrum; and

configure the UE to tune to the NB IOT carrier operating in the unlicensed spectrum to communicate data using the NB IOT carrier in the unlicensed spectrum.

89. The base station of claim 88, wherein the NB IOT carrier in the unlicensed spectrum is carrier-aggregation synchronized to a licensed carrier in the licensed spectrum.

90. The base station of claim 88, wherein the at least one processor is further configured to:

transmit hopping pattern information of a plurality of hopping carriers in the unlicensed spectrum to the UE to configure the UE with the hopping pattern information,

wherein the hopping pattern information includes at least one of;

a number of the plurality of hopping carriers, information for generating a hopping pattern, subframe number to start hopping, dwell time information per channel, or power restraints on the unlicensed carrier.

91. The base station of claim 88, wherein the at least one processor is further configured to:

configure the UE to retune to a licensed carrier in the licensed spectrum to perform another synchronization after communicating the data via the NB IOT carrier in the unlicensed spectrum; and

; and

perform the another synchronization on the licensed carrier in the licensed spectrum.

92. The base station of claim 87, wherein the at least one processor configured to perform the synchronization is configured to:

configure a downlink channel to transmit a downlink communication in a licensed spectrum; and

configure an uplink channel to receive an uplink communication in the unlicensed spectrum,

wherein the at least one processor is further configured to;

transmit at least one of a downlink grant or a uplink grant via downlink communication in the licensed spectrum;

receive the uplink communication in the unlicensed spectrum if the uplink grant is transmitted; and

transmit the downlink communication in the licensed spectrum if the downlink grant is transmitted.

93. The base station of claim 87, wherein the at least one processor configured to perform the synchronization is configured to:

perform the synchronization in the unlicensed spectrum, and

wherein the base station further comprises switching to a different carrier for the synchronization in the unlicensed spectrum upon expiration of a dwell time on a current carrier.

94. The base station of claim 93, wherein the different carrier includes one or more carriers corresponding to one or more hopping frequencies that are aligned with a channel raster in the unlicensed spectrum.

95. The base station of claim 94, wherein the at least one processor configured to configure to perform the synchronization is configured to perform at least one of:

utilizing the channel raster that is less than 100 KHz, or

setting a hopping bandwidth based on a hopping bandwidth indication.

96. The base station of claim 93, wherein the at least one processor is further configured to:

before switching to the different carrier upon expiration of the dwell time, transmit at least one of;

a frequency hopping indication indicating whether frequency hopping exists,

an end indication of dwell time on a current hopping frequency, or

a next hopping frequency.

97. The base station of claim 93, wherein the at least one processor is further configured to:

transmit a hopping pattern change indication indicating that a hopping pattern of a plurality of frequencies is scheduled to change; and

transmit hopping information including a new hopping pattern based on the hopping pattern change indication.

98. The base station of claim 93, wherein the at least one processor configured to transmit the hopping information is configured to perform at least one of:

transmitting the hopping information via at least one of a narrowband primary synchronization signal (NPSS), a narrowband secondary synchronization signal (NSSS), or a narrowband physical broadcast channel (NPBCH) within a dwell time,

transmitting the hopping information via a system information block (SIB) within the dwell time, or

if the hopping information is provided via radio resource control (RRC), performing at least one of RRC connection setup or RRC connection re-establishment within the dwell time.

99. The base station of claim 93, wherein the at least one processor is further configured to:

transmitting an end indication of a dwell time on a current hopping frequency corresponding to the current carrier, wherein the transmitting the end indication comprises at least one of;

providing the end indication in a first three symbols in a subframe carrying a narrowband primary synchronization signal (NPSS) to indicate a last NPSS transmission before hopping from the current hopping frequency to another frequency, or

providing the end indication in a first three symbols in a subframe carrying a narrowband secondary synchronization signal (NSSS) to indicate a last NSSS transmission before hopping from the current hopping frequency to the another frequency.

100. The base station of claim 93, wherein the frequency hopping is non-uniform.

101. The base station of claim 100, wherein the base station hops to an anchor frequency more often than to one or more non-anchor frequencies.

102. The base station of claim 100, wherein the base station hops to one frequency more often than to another frequency based on signal interference.

103. A computer-readable medium storing computer executable code, for a user equipment (UE) for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation, comprising code to:

perform a synchronization with a base station via at least one of a licensed spectrum or the unlicensed spectrum; and

communicate with the base station based on the synchronization.

104. A computer-readable medium storing computer executable code, for a base station for wireless communication via narrowband internet of things (NB IOT) in an unlicensed spectrum using frequency hopping and digital modulation, comprising code to:

perform a synchronization with a user equipment (UE) via at least one of a licensed spectrum or the unlicensed spectrum; and

communicate with the UE based on the synchronization.