Activation of grant-free transmission
Systems, apparatuses, and methods are described for wireless communications. A base station may send a message to a wireless device to activate grant-free uplink transmissions for a non-activated cell. The wireless device may receive the message and activate a previously non-activated cell.
1. A method comprising:
receiving, by a wireless device from a base station, at least one radio resource control message comprising one or more configuration parameters of a cell, wherein the one or more configuration parameters indicate grant free uplink radio resources associated with the cell;
after the receiving the at least one radio resource control message, receiving a medium access control (MAC) control element (CE) indicating an activation of the cell;
in response to the receiving the MAC CE, activating the cell;
in response to the receiving the MAC CE, activating the grant free uplink radio resources associated with the cell; and
transmitting, by the wireless device to the base station via the grant free uplink radio resources, one or more data packets.
2. The method of claim 1 , wherein the cell comprises a secondary cell.
3. The method of claim 1 , wherein the one or more configuration parameters further indicate at least one of:
demodulation reference signal configuration parameters;
a radio network temporary identifier; or
a preamble identifier.
4. The method of claim 3 , wherein the preamble identifier comprises a Zadoff-Chu sequence.
5. The method of claim 1 , wherein:
the one or more configuration parameters further comprise a modulation and coding scheme; and
the transmitting comprises transmitting, using the modulation and coding scheme, the one or more data packets.
6. The method of claim 1 , wherein:
the one or more configuration parameters further comprise a quantity of permitted repeat transmissions of the one or more data packets; and
the transmitting comprises transmitting, based on the quantity of permitted repeat transmissions, the one or more data packets.
7. The method of claim 1 , wherein the one or more configuration parameters further comprise at least one of:
an indication that the grant free uplink radio resources associated with the cell are activated based on the receiving the at least one radio resource control message; or
an indication that the grant free uplink radio resources associated with the cell are activated based on receiving a control signal from the base station.
8. The method of claim 7 , further comprising:
receiving, via a downlink control channel, the control signal; and
based on the receiving the control signal, activating the grant free uplink radio resources associated with the cell.
9. The method of claim 7 , wherein the control signal is scrambled by a radio network temporary identifier.
10. The method of claim 7 , further comprising transmitting, based on the receiving the control signal, an acknowledgement.
11. The method of claim 1 , further comprising receiving a response message associated with the one or more data packets.
12. The method of claim 11 , wherein the response message comprises downlink control information.
13. The method of claim 1 , wherein the activation of the cell comprises reactivation of a deactivated cell.
14. A method comprising:
receiving, by a wireless device from a base station, at least one radio resource control message comprising one or more configuration parameters for a cell, wherein the one or more configuration parameters indicate grant free uplink radio resources associated with the cell;
based on the receiving the at least one radio resource control message, activating the grant free uplink radio resources associated with the cell;
determining an expiry of a time alignment timer of a cell group comprising the cell;
based on the expiry of the time alignment timer, clearing the grant free uplink radio resources;
receiving a timing advance command associated with the cell group;
based on the receiving the timing advance command, re-activating the grant free uplink radio resources; and
based on the timing advance command, transmitting, via the grant free uplink radio resources, one or more data packets.
15. The method of claim 14 , wherein the one or more configuration parameters further comprise at least one of:
an indication that the grant free uplink radio resources associated with the cell are activated based on the receiving the at least one radio resource control message; or
an indication that the grant free uplink radio resources associated with the cell are activated based on receiving a control signal from the base station.
16. The method of claim 14 , wherein the cell comprises a secondary cell.
17. The method of claim 14 , wherein:
the one or more configuration parameters further comprise a modulation and coding scheme; and
the transmitting comprises transmitting, using the modulation and coding scheme, the one or more data packets.
18. The method of claim 14 , wherein:
the one or more configuration parameters further comprise a quantity of permitted repeat transmissions of the one or more data packets; and
the transmitting comprises transmitting, based on the quantity of permitted repeat transmissions, the one or more data packets.
19. The method of claim 14 , further comprising:
receiving a response message associated with the one or more data packets, wherein the response message comprises downlink control information.
20. A method comprising:
receiving, by a wireless device from a base station, at least one radio resource control message comprising one or more configuration parameters for a cell, wherein the one or more configuration parameters indicate grant free uplink radio resources associated with the cell;
receiving a medium access control (MAC) control element (CE) indicating an activation of the cell;
based on the receiving the MAC CE, activating the grant free uplink radio resources;
determining an expiry of a time alignment timer of a cell group comprising the cell;
based on the expiry of the time alignment timer, clearing the grant free uplink radio resources;
receiving a timing advance command for the cell group;
based on the receiving the timing advance command, re-activating the grant free uplink radio resources; and
transmitting, via the grant free uplink radio resources, one or more data packets.
21. The method of claim 20 , wherein the one or more configuration parameters further comprise at least one of:
an indication that the grant free uplink radio resources associated with the cell are activated based on the receiving the at least one radio resource control message; or
an indication that the grant free uplink radio resources associated with the cell are activated based on receiving a control signal from the base station.
22. The method of claim 20 , wherein the cell comprises a secondary cell.
23. The method of claim 20 , wherein:
the one or more configuration parameters further comprise a modulation and coding scheme; and
the transmitting comprises transmitting, using the modulation and coding scheme, the one or more data packets.
24. The method of claim 20 , wherein:
the one or more configuration parameters further comprise a quantity of permitted repeat transmissions of the one or more data packets; and
the transmitting comprises transmitting, based on the quantity of permitted repeat transmissions, the one or more data packets.
25. The method of claim 20 , further comprising:
receiving a response message associated with the one or more data packets, wherein the response message comprises downlink control information.