Activation of secondary cell containing bandwidth parts
5G methods and architectures to determine active SCells and their bandwidth parts (BWP) used in carrier aggregation (CA) are disclosed in which activating a BWP for an active SCell is performed initially according to a default value provided in initial radio resource control (RRC) messaging. After initialization, SCells and the SCell BWPs used by the user equipment (UE) are activated by RRC messaging, downlink control information (DCI) or dedicated medium access control (MAC) control elements (MAC CEs) with the initial BWP used for an activated SCell being a default value provided during initialization.
1. A baseband (BB) processor for a user equipment (UE) enabled for carrier-aggregation communication with primary cells (PCells) and secondary cells (SCells), configured to:
receive a radio resource control (RRC) signaling from a base station to add a secondary cell (SCell), wherein the RRC signaling comprises a configuration of one or more bandwidth parts (BWPs) associated with the SCell, including a default BWP;
activate a BWP for the SCell, wherein the activated BWP is different from the default BWP;
start a BWP timer for the BWP;
stop the BWP timer when the SCell is deactivated; and
switch the BWP for the SCell to the default BWP when the SCell is re-activated.
2. The BB processor of claim 1 , wherein the SCell is deactivated via signaling selected from a group consisting of RRC signaling, downlink control information (DCI) signaling, and dedicated medium access control (MAC) control element (CE) instruction.
3. The BB processor of claim 1 , configured to activate the BWP for the SCell in response to receiving a physical downlink control channel (PDCCH) message activating the BWP.
4. The BB processor of claim 1 , wherein the RRC signaling further indicates a first active downlink BWP, wherein the first active downlink BWP is active for the SCell when a PDCCH message activating a BWP is not received.
5. A base station (BS) comprising:
a memory; and
one or more processors coupled to the memory and configured to:
generate a radio resource control (RRC) signaling to add a secondary cell (SCell), wherein the RRC signaling comprises a configuration of one or more bandwidth parts (BWPs) associated with the SCell, including a default BWP;
cause transmission of the RRC signaling to a UE;
cause transmission of a message activating a BWP for the SCell, wherein the activated BWP is different from the default BWP;
start a BWP timer for the BWP;
stop the BWP timer when the SCell is deactivated; and
switch the BWP for the SCell to the default BWP when the SCell is re-activated.
6. The BS of claim 5 , wherein the one or more processors are configured to deactivate the SCell via signaling selected from a group consisting of RRC signaling, downlink control information (DCI) signaling, and dedicated medium access control (MAC) control element (CE) instruction.
7. The BS of claim 5 , wherein the one or more processors are configured to activate the BWP for the SCell in response to receiving a physical downlink control channel (PDCCH) message activating the BWP.
8. The BS of claim 5 , wherein the RRC signaling further indicates a first active downlink BWP, wherein the first active downlink BWP is active for the SCell when a PDCCH message activating a BWP is not received.
9. A method for a user equipment (UE) enabled for carrier-aggregation communication with primary cells (PCells) and secondary cells (SCells), comprising:
receiving a radio resource control (RRC) signaling from a base station to add a secondary cell (SCell), wherein the RRC signaling comprises a configuration of one or more bandwidth parts (BWPs) associated with the SCell, including a default BWP;
activating a BWP for the SCell, wherein the activated BWP is different from the default BWP;
starting a BWP timer for the BWP;
stopping the BWP timer upon deactivation of the SCell; and
switching the BWP for the SCell to the default BWP when the SCell is re-activated.
10. The method of claim 9 , wherein the SCell is deactivated via signaling selected from a group consisting of RRC signaling, downlink control information (DCI) signaling, and dedicated medium access control (MAC) control element (CE) instruction.
11. The method of claim 9 , comprising activating the BWP for the SCell in response to receiving a physical downlink control channel (PDCCH) message activating the BWP.
12. The method of claim 9 , wherein the RRC signaling further indicates a first active downlink BWP, wherein the first active downlink BWP is active for the SCell when a PDCCH message activating a BWP is not received.