Component carrier activation/deactivation in multi carrier systems
Methods and apparatus for addressing wireless transmit/receive unit (WTRU) behavior in response to configuration, configuration parameters and access issues related to the activation/deactivation process when the WTRU may be configured with multiple serving cells or carrier aggregation.
1. A method implemented at a wireless transmit/receive unit, WTRU, for handling carrier aggregation, comprising:
establishing a connection with a primary cell (PCell);
configuring the WTRU with a secondary cell (SCell);
receiving an activation/deactivation medium access control (MAC) control element (CE) comprising fields for signaling activation/deactivation states for multiple SCells;
determining the activation/deactivation state for the SCell using an identity of the SCell as an index to the activation/deactivation MAC CE;
activating or deactivating the SCell based on the determined activation/deactivation state;
triggering a power headroom report (PHR) responsive to activation of the SCell and on a condition that the SCell is configured for uplink transmission; and
generating a MAC protocol data unit (PDU) including a PHR MAC CE to report the triggered PHR in a next available transmission opportunity based on a size of the PHR MAC CE and on condition that the WTRU has allocated uplink resources and the triggered PHR is pending for transmission.
2. The method of claim 1 , wherein the SCell is activated on condition that the determined activation/deactivation state commands an activation of the SCell.
3. The method of claim 1 , wherein the SCell is deactivated on condition that the determined activation/deactivation state commands a deactivation of the SCell.
4. The method of claim 1 , further comprising:
on a condition that the SCell is configured for reception of a physical downlink control channel, starting a monitoring of the physical downlink control channel in response to activation of the SCell.
5. The method of claim 1 , further comprising:
receiving a cross-carrier scheduling configuration; and
determining, from the cross-carrier scheduling configuration, a starting symbol of a physical downlink shared channel for the SCell.
6. The method of claim 1 , further comprising:
responsive to deactivation of the SCell,
stopping a monitoring of a physical downlink control channel for the SCell; and
stopping receiving downlink assignments or uplink grants associated with the SCell.
7. The method of claim 1 , further comprising:
receiving a cross-carrier scheduling configuration; and
determining, based on the cross-carrier scheduling configuration, a serving cell for receiving downlink allocations or uplink grants for the SCell.
8. The method of claim 1 , further comprising:
responsive to deactivation of the SCell, stopping a reporting of a channel quality indicator, a precoding matrix index, or a rank indication for the SCell.
9. The method of claim 1 , further comprising:
responsive to deactivation of the SCell, releasing a sounding reference signal reporting configuration for the SCell.
10. The method of claim 1 , further comprising:
releasing a configuration for the SCell responsive to an indication of a radio resource controller connection re-establishment.
11. The method of claim 1 , wherein the activation/deactivation MAC CE includes a bitmap, and wherein each bit in the bitmap corresponds to, and indicates the activation/deactivation states of, one of the multiple SCells.
12. The method of claim 1 , wherein the SCell is initially configured in a deactivated state.
13. The method of claim 1 , wherein the SCell is configured using an SCell configuration received via dedicated signaling, and wherein the SCell configuration comprises the identity of the SCell and a radio resource configuration that identifies configuration parameters for downlink (DL) and uplink (UL) resources of the SCell.
14. The method of claim 1 , wherein a deactivation timer is started or restarted responsive to the activation/deactivation MAC CE signaling activation of the SCell.
15. The method of claim 14 , wherein the activation/deactivation MAC CE is received prior to expiry of the deactivation timer.
16. The method of claim 1 , further comprising transmitting the MAC PDU at the next available transmission opportunity.
17. The method of claim 1 , wherein the PHR MAC CE includes a valid PHR value for at least the SCell.
18. A wireless transmit/receive unit, WTRU, configured for carrier aggregation, comprising:
a transceiver; and
a processor in communication with the transceiver,
wherein the processor is configured to:
establish a connection with a primary cell (PCell);
configure the WTRU with a secondary cell (SCell);
receive an activation/deactivation medium access control (MAC) control element (CE) comprising fields for signaling activation/deactivation states for multiple SCells;
determine the activation/deactivation state for the SCell using an identity of the SCell as an index to the activation/deactivation MAC CE;
activate or deactivate the SCell based on the determined activation/deactivation state;
trigger a power headroom report responsive to activation of the SCell, and on a condition that the SCell is configured for uplink transmission; and
generate a MAC protocol data unit (PDU) including a PHR MAC CE to report the triggered PHR in a next available transmission opportunity based on a size of the PHR MAC CE and on a condition that the WTRU has allocated uplink resources and the triggered PHR is pending for transmission.
19. The WTRU of claim 18 , wherein the SCell is activated on condition that the determined activation/deactivation state commands an activation of the SCell.
20. The WTRU of claim 18 , wherein the SCell is deactivated on condition that the determined activation/deactivation state commands a deactivation of the SCell.
21. The WTRU of claim 18 , wherein the processor is further configured to:
on a condition that the SCell is configured for reception of a physical downlink control channel, start a monitoring of the physical downlink control channel in response to activation of the SCell.
22. The WTRU of claim 18 , wherein the processor is further configured to:
receive a cross-carrier scheduling configuration; and
determine, from the cross-carrier scheduling configuration, a starting symbol of a physical downlink shared channel for the SCell.
23. The WTRU of claim 18 , wherein the processor is further configured to:
responsive to deactivation of the SCell,
stop a monitoring of a physical downlink control channel for the SCell; and
stop receiving downlink assignments or uplink grants associated with the SCell.
24. The WTRU of claim 18 , wherein the processor is further configured to:
receive a cross-carrier scheduling configuration; and
determine, based on the cross-carrier scheduling configuration, a serving cell for receiving downlink allocations or uplink grants for the SCell.
25. The WTRU of claim 18 , wherein the processor is further configured to:
responsive to deactivation of the SCell, stop a reporting of a channel quality indicator, a precoding matrix index, or a rank indication for the SCell.
26. The WTRU of claim 18 , wherein the processor is further configured to:
responsive to deactivation of the SCell, release a sounding reference signal reporting configuration for the SCell.
27. The WTRU of claim 18 , wherein the processor is further configured to:
release a configuration for the SCell responsive to an indication of a radio resource controller connection re-establishment.
28. The WTRU of claim 18 , wherein the activation/deactivation MAC CE includes a bitmap, and wherein each bit in the bitmap corresponds to, and indicates the activation/deactivation states of, one of the multiple SCells.
29. The WTRU of claim 18 , wherein the SCell is initially configured in a deactivated state.
30. The WTRU of claim 18 , wherein the SCell is configured using an SCell configuration received via dedicated signaling, and wherein the SCell configuration comprises the identity of the SCell and a radio resource configuration that identifies configuration parameters for downlink (DL) and uplink (UL) resources of the SCell.
31. The WTRU of claim 18 , wherein a deactivation timer is started or restarted responsive to the activation/deactivation MAC CE signaling activation of the SCell.
32. The WTRU of claim 31 , wherein the activation/deactivation MAC CE is received prior to expiry of the deactivation timer.
33. The WTRU of claim 18 , wherein the processor is further configured to transmit the MAC PDU at the next available transmission opportunity.
34. The WTRU of claim 18 , wherein the PHR MAC CE includes a valid PHR value for at least the SCell.