Method and apparatuses for performing unscheduled uplink transmissions on an unlicensed band

1. A method, for a user equipment, UE, for performing an unscheduled uplink transmission in an unlicensed portion of a radio spectrum, the method comprising:

performing, by the UE, a listen before talk, LBT, operation in the unlicensed portion of the radio spectrum, wherein the LBT operation comprises sensing the unlicensed portion of the radio spectrum for a pre-determined minimum amount of time for traffic; and, if no traffic was sensed;

performing the unscheduled uplink transmission, by the UE, of data in an unscheduled mode of operation for at least one transmission burst, wherein performing the unscheduled uplink transmission, by the UE, of data in an unscheduled mode of operation for at least one transmission burst is repeated until an earliest opportunity to transmit a scheduling request, SR, occurs, and wherein the transmission of the SR can occur on one of a licensed carrier or an unlicensed carrier.

2. The method of claim 1 , further comprising:

activating, after transmitting the at least one transmission burst, a schedule based channel access mechanism, wherein—the eNB controls the UE's uplink access; and

receiving, by the UE, after transmitting the at least one transmission burst, the uplink transmission grant via cross carrier scheduling.

3. The method of claim 2 , wherein the uplink transmission grant allows for scheduling the data on another carrier in a licensed portion or the unlicensed portion of the radio spectrum.

4. The method of claim 1 , further comprising:

activating, after transmitting the at least one transmission burst, a schedule based channel access mechanism, wherein the eNB controls the UE's uplink access; and

receiving, by the UE after transmitting the at least one transmission burst, the uplink transmission grant on the same carrier as the data-transmission is scheduled.

5. The method of claim 1 , wherein the unscheduled uplink transmissions are restricted in time to pre-specified time windows.

6. A method, for an eNodeB, eNB, for an unscheduled uplink transmission in an unlicensed portion of a radio spectrum, the method comprising:

controlling a user equipment's, UE's, uplink access, after receiving at least one transmission burst in an unscheduled mode of operation from the UE, using a schedule based channel access mechanism; wherein controlling the UE's uplink access comprises:

transmitting, to the UE, an uplink transmission grant for scheduled-based channel access;

wherein receiving the at least one transmission burst is repeated until an earliest opportunity for the UE to transmit a scheduling request, SR, occurs, and wherein the transmission of the SR can occur on one of a licensed carrier or an unlicensed carrier.

7. The method of claim 6 , wherein the uplink transmission grant is transmitted via cross carrier scheduling.

8. The method of claim 6 , wherein the uplink transmission grant is transmitted on the same carrier as the data-transmission is scheduled.

9. The method of claim 6 , wherein the unscheduled uplink transmissions are restricted in time to the pre-specified time windows.

10. The method of claim 9 , further comprising:

signaling, to the UE, specific sub-frames in which unscheduled transmissions are allowed.

11. The method of claim 6 , wherein the at least one uplink transmission burst has embedded identification of the UE.

12. A User Equipment, UE, configured to perform an unscheduled uplink transmission in an unlicensed portion of a radio spectrum, the UE comprising a processor, a memory, and transceiver, said memory comprising instructions executable by said processor and by said transceiver whereby the UE is operative to:

perform a listen before talk, LBT, operation in the unlicensed portion of the radio spectrum, wherein the LBT operation comprises sensing the unlicensed portion of the radio spectrum for a pre-determined minimum amount of time for traffic; and, if no traffic was sensed,

perform the unscheduled uplink transmission, by the UE, of data in an unscheduled mode of operation for at least one transmission burst, wherein performing the unscheduled uplink transmission, by the UE, of data in an unscheduled mode of operation for at least one transmission burst is repeated until an earliest opportunity to transmit a scheduling request, SR, occurs, and wherein the transmission of the SR can occur on one of a licensed carrier or an unlicensed carrier.

13. The UE of claim 12 , further operative to:

activate, after transmitting the at least one transmission burst, a schedule based channel access mechanism, wherein—the eNB controls the UE's uplink access; and

receive, after transmitting the at least one transmission burst, the uplink transmission grant via cross carrier scheduling.

14. The UE of claim 13 , wherein the uplink transmission grant allows for scheduling the data on another carrier in a licensed portion or the unlicensed portion of the radio spectrum.

15. The UE of claim 12 , further operative to:

activate, after transmitting the at least one transmission burst, a schedule based channel access mechanism, wherein the eNB controls the UE's uplink access; and

receive, after transmitting the at least one transmission burst, the uplink transmission grant on the same carrier as the data-transmission is scheduled.

16. The UE of claim 12 , wherein the unscheduled uplink transmissions which are restricted in time to the pre-specified time windows.

17. An eNodeB, eNB, configured for an unscheduled uplink transmission in an unlicensed portion of a radio spectrum, the eNB comprising a processor, a memory, and an interface, said memory comprising instructions executable by said processor and by said interface, whereby the eNB is operative to:

control a user equipment's, UE's, uplink access, after receiving at least one transmission burst in an unscheduled mode of operation from the UE, using a schedule based channel access mechanism; wherein controlling the UE's uplink access comprises:

transmit, to the UE, an uplink transmission grant for scheduled-based channel access;

wherein receiving the at least one transmission burst is repeated until an earliest opportunity for the UE to transmit a scheduling request, SR, occurs, and wherein the transmission of the SR can occur on one of a licensed carrier or an unlicensed carrier.

18. The eNB of claim 17 , further operative to:

inform neighboring eNB s whether the unscheduled mode of operation is active for at least one UE;

receive information from the neighboring eNB s associated with a level of interference when the level of interference is greater than a pre-determined threshold; and

instruct the at least one UE to switch from the unscheduled mode of operation to a scheduled mode of operation.