Unlicensed spectrum operation for narrowband internet of things and enhanced machine type communication
Methods, systems, and devices for wireless communication are described. A user equipment (UE) and base station may communicate using narrow band internet of things (NB-IoT) techniques or enhanced machine type communication (eMTC) in unlicensed spectrum. The UE may be an eMTC device or another device capable of communication without user direction. The UE may identify a geographic region and select a communication mode that is consistent with regulatory restrictions in that region. For example, in some cases, the communication mode may be based on using time division duplexing (TDD), using frequency hopping, or performing a listen-before-talk (LBT) procedure at the base station. A frame structure for TDD may include LBT subframes, uplink portions, downlink portions, and special subframes for switching. The base station may perform LBT procedures in the LBT subframes. If frequency hopping is enabled, a configurable number of TDD frames may be grouped into a hopping frame block.
1. A method for wireless communication, comprising:
identifying a narrowband region of an unlicensed radio frequency spectrum band for communication with a wireless device;
determining a geographic operating region for the wireless device;
selecting a communication mode from a plurality of communication modes for communication in the unlicensed radio frequency spectrum band based at least in part on the narrowband region and the geographic operating region for the wireless device, wherein the communication mode indicates that frequency hopping is enabled for the communication in the unlicensed radio frequency spectrum band, wherein a configurable number of time division duplexed frames are grouped into a hopping frame block; and
communicating with the wireless device in the narrowband region of the unlicensed radio frequency spectrum band using the communication mode.
2. The method of claim 1 , further comprising:
receiving a system information broadcast in the narrowband region, wherein the communication mode or the geographic operating region is identified based at least in part on the system information broadcast.
3. The method of claim 1 , further comprising:
transmitting a system information broadcast in the narrowband region, wherein the system information broadcast identifies the communication mode or the geographic operating region.
4. The method of claim 1 , wherein the communication mode is based at least in part on a regulatory restriction of the geographic operating region.
5. The method of claim 1 , wherein the communication mode is selected based at least in part on a capability or category of the wireless device.
6. The method of claim 5 , further comprising:
transmitting an indication of the capability or category of the wireless device.
7. The method of claim 5 , wherein the capability or category of the wireless device comprises a narrowband internet of things (NB-IoT) or enhanced machine type communication (eMTC) capability or category.
8. The method of claim 1 , further comprising:
identifying a number of frequency hopping channels based at least in part on the communication mode, wherein communicating in the narrowband region of the unlicensed radio frequency spectrum band is based at least in part on the number of frequency hopping channels.
9. The method of claim 1 , wherein the communication mode further comprises a listen-before-talk (LBT) configuration, the method further comprising:
identifying a time division duplexing (TDD) frame structure based at least in part on the LBT configuration, wherein communicating in the narrowband region of the unlicensed radio frequency spectrum band is based at least in part on the TDD frame structure.
10. The method of claim 9 , wherein the LBT configuration comprises an active LBT configuration, and the TDD frame structure includes at least one LBT gap.
11. The method of claim 9 , wherein the LBT configuration comprises an inactive LBT configuration, and the TDD frame structure includes a combination of uplink or downlink transmission time intervals (TTIs) and excludes an LBT gap.
12. The method of claim 9 , wherein communicating comprises communicating in the narrowband region of the unlicensed radio frequency spectrum band during a first TDD frame having the TDD frame structure, the method further comprising:
communicating in a second narrowband region of the unlicensed radio frequency spectrum band during a second TDD frame having the TDD frame structure.
13. The method of claim 9 , wherein the TDD frame structure comprises a downlink portion and an uplink portion separated by at least one special transmission time interval (TTI).
14. The method of claim 1 , wherein the communication mode further comprises a discontinuous transmission (DTX) duty cycle, the method further comprising:
identifying a DTX configuration based at least in part on the DTX duty cycle; and
entering an idle mode based at least in part on the DTX configuration.
15. An apparatus for wireless communication, comprising:
means for identifying a narrowband region of an unlicensed radio frequency spectrum band for communication with a wireless device;
means for determining a geographic operating region for the wireless device;
means for selecting a communication mode from a plurality of communication modes for communication in the unlicensed radio frequency spectrum band based at least in part on the narrowband region and the geographic operating region for the wireless device, wherein the communication mode indicates that frequency hopping is enabled for the communication in the unlicensed radio frequency spectrum band, wherein a configurable number of time division duplexed frames are grouped into a hopping frame block; and
means for communicating with the wireless device in the narrowband region of the unlicensed radio frequency spectrum band using the communication mode.
16. An apparatus for wireless communication, in a system comprising:
a processor;
a memory in electronic communication with the processor; and
instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:
identify a narrowband region of an unlicensed radio frequency spectrum band for communication with a wireless device;
determine a geographic operating region for the wireless device;
select a communication mode from a plurality of communication modes for communication in the unlicensed radio frequency spectrum band based at least in part on the narrowband region and the geographic operating region for the wireless device, wherein the communication mode indicates that frequency hopping is enabled for the communication in the unlicensed radio frequency spectrum band, wherein a configurable number of time division duplexed frames are grouped into a hopping frame block; and
communicate with the wireless device in the narrowband region of the unlicensed radio frequency spectrum band using the communication mode.
17. The apparatus of claim 16 , wherein the instructions are further executable by the processor to cause the apparatus to:
receive a system information broadcast in the narrowband region; and
identify the communication mode or the geographic operating region based at least in part on the system information broadcast.
18. The apparatus of claim 16 , wherein the instructions are further executable by the processor to cause the apparatus to:
transmit a system information broadcast in the narrowband region, wherein the system information broadcast identifies the communication mode or the geographic operating region.
19. The apparatus of claim 16 , wherein the communication mode is based at least in part on a regulatory restriction of the geographic operating region.
20. The apparatus of claim 16 , wherein the communication mode is selected based at least in part on a capability or category of the wireless device.
21. The apparatus of claim 20 , wherein the instructions are further executable by the processor to cause the apparatus to:
transmit an indication of the capability or category of the wireless device.
22. The apparatus of claim 20 , wherein the capability or category of the wireless device comprises a narrowband internet of things (NB-IoT) or enhanced machine type communication (eMTC) capability or category.
23. The apparatus of claim 16 , wherein the instructions are further executable by the processor to cause the apparatus to:
identify a number of frequency hopping channels based at least in part on the communication mode, wherein communicating in the narrowband region of the unlicensed radio frequency spectrum band is based at least in part on the number of frequency hopping channels.
24. The apparatus of claim 16 , wherein the communication mode further comprises a listen-before-talk (LBT) configuration, and wherein the instructions are further executable by the processor to cause the apparatus to:
identify a time division duplexing (TDD) frame structure based at least in part on the LBT configuration, wherein communicating in the narrowband region of the unlicensed radio frequency spectrum band is based at least in part on the TDD frame structure.
25. The apparatus of claim 24 , wherein the LBT configuration comprises an active LBT configuration, and the TDD frame structure includes at least one LBT gap.
26. The apparatus of claim 24 , wherein the LBT configuration comprises an inactive LBT configuration, and the TDD frame structure includes a combination of uplink or downlink transmission time intervals (TTIs) and excludes an LBT gap.
27. The apparatus of claim 24 , wherein communicating comprises communicating in the narrowband region of the unlicensed radio frequency spectrum band during a first TDD frame having the TDD frame structure, the instructions further executable by the processor to cause the apparatus to:
communicate in a second narrowband region of the unlicensed radio frequency spectrum band during a second TDD frame having the TDD frame structure.
28. The apparatus of claim 24 , wherein the TDD frame structure comprises a downlink portion and an uplink portion separated by at least one special transmission time interval (TTI).
29. The apparatus of claim 16 , wherein the communication mode further comprises a discontinuous transmission (DTX) duty cycle, and wherein the instructions are further executable by the processor to cause the apparatus to:
identify a DTX configuration based at least in part on the DTX duty cycle; and
enter an idle mode based at least in part on the DTX configuration.
30. A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:
identify a narrowband region of an unlicensed radio frequency spectrum band for communication with a wireless device;
determine a geographic operating region for the wireless device;
select a communication mode from a plurality of communication modes for communication in the unlicensed radio frequency spectrum band based at least in part on the narrowband region and the geographic operating region for the wireless device, wherein the communication mode indicates that frequency hopping is enabled for the communication in the unlicensed radio frequency spectrum band, wherein a configurable number of time division duplexed frames are grouped into a hopping frame block; and
communicate with the wireless device in the narrowband region of the unlicensed radio frequency spectrum band using the communication mode.