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 perform operations 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) and an explicit indication of a first bandwidth part (BWP) of the one or more BWPs that is to be activated during activation of the SCell;
receiving a medium access control (MAC) control element (CE) message from the base station, wherein the MAC CE message comprises an indication to activate the SCell;
activating the SCell based on the MAC CE; and
activating the first BWP based on the RRC signaling, upon activation of the SCell.
2. The BB processor of claim 1 , wherein the RRC signaling comprises a firstActiveDownlinkBWP-Id to indicate the first BWP, when the first BWP comprises a downlink (DL) BWP.
3. The BB processor of claim 1 , wherein the RRC signaling comprises a firstActiveUplinkBWP-Id to indicate the first BWP, when the first BWP comprises an uplink (UL) BWP.
4. The BB processor of claim 1 , wherein the SCell that is activated or the first BWP that is activated may be changed by subsequent downlink control information (DCI).
5. The BB processor of claim 1 , wherein the RRC signaling includes an IE SCellConfig to indicate the SCell to be added.
6. A base station (BS) comprising:
a memory; and
one or more processors coupled to the memory and configured to:
send a radio resource control (RRC) signaling to a user equipment (UE) to add a secondary cell (SCell), wherein the RRC signaling comprises a configuration of one or more bandwidth parts (BWPs) and an explicit indication of a first bandwidth part (BWP) of the one or more BWPs that is to be activated during activation of the SCell; and
send a medium access control (MAC) control element (CE) message to the UE, wherein the MAC CE message comprises an indication to activate the SCell.
7. The BS of claim 6 , wherein the RRC signaling comprises a firstActiveDownlinkBWP-Id to indicate the first BWP, when the first BWP comprises a downlink (DL) BWP.
8. The BS of claim 6 , wherein the RRC signaling comprises a firstActiveUplinkBWP-Id to indicate the first BWP, when the first BWP comprises an uplink (UL) BWP.
9. The BS of claim 6 , wherein the SCell that is activated or the first BWP that is activated may be changed by subsequent downlink control information (DCI).
10. The BS of claim 6 , wherein the RRC signaling includes an IE SCellConfig to indicate the SCell to be added.
11. A baseband (BB) processor for a user equipment (UE) in a wireless network capable of carrier aggregation (CA), configured to perform operations 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) and an explicit indication of a first bandwidth part (BWP) of the one or more BWPs that is to be activated during activation of the SCell;
activating the SCell for the CA, and the first BWP for communications with the SCell that is activated;
starting a timer for the first BWP that is activated;
performing a BWP switch to a default BWP, when the timer for the first BWP that is activated expires; and
stopping the timer, when the SCell is deactivated.
12. The BB processor of claim 11 , wherein the SCell and the first BWP are activated based on a medium access control (MAC) control element (MAC CE) message.
13. The BB processor of claim 12 , wherein the MAC CE is of fixed size and includes BWP index fields and SCell index fields.