Methods for carrier aggregation
Methods to manage multiple component carriers (CCs) efficiently in a mobile network with carrier aggregation (CA) enabled are proposed. For CC activation/deactivation, a single LCID value is used to represent both activation and deactivation command. A single command with multiple instructions is provided to activate and/or deactivate multiple CCs. In addition, unnecessary re-activation or re-inactivation of a CC is prevented, and explicit feedback for activation/deactivation is considered. For scheduling mechanism, a novel buffer status reporting (BSR) procedure is provided, where only one BSR is calculated after preparing all the transport blocks (TB) within one transmission time interval (TTI). Novel power headroom reporting (PHR) format and trigger are also provided. For DL-UL linking, various linking types are created based on whether there is carrier indicator field (CIF) in DL grant or UL grant. The various linking types are used in different applications to improve scheduling flexibility and load balancing.
1. A method comprising:
receiving an activation or deactivation command for one or more component carriers (CCs) by a user equipment (UE) in a wireless communication network, wherein the one or more CCs are initialized;
determining a current state of each CC in the activation or deactivation command; and
deriving a plurality of instructions corresponds to the one or more CCs based on the command, wherein the UE activates a CC if and only if the current state of the CC is deactivated and a corresponding instruction is for activation, wherein the UE deactivates the CC if and only if the current state of the CC is activated and a corresponding instruction is for deactivation, and wherein the UE does not change the current state of the CC otherwise.
2. The method of claim 1 , wherein the command is contained in a media access control (MAC) control element (CE), and wherein each bit is associated with an activation or deactivation instruction for a corresponding CC.
3. The method of claim 1 , further comprising:
starting an deactivation timer for a secondary CC (SCC) based on a set of predefined events; and
deactivating the SCC when the deactivation timer expires.
4. The method of claim 3 , wherein the set of predefined events comprises at least one of a secondary CC is activated, a downlink assignment is received, an uplink grant is received, a configured transmission takes place, and an activation command is received.
5. The method of claim 1 , further comprising:
transmitting feedback information in respond to the command based on an activation or deactivation status, wherein the activation status indicates the CC is activated and the deactivation status indicates the CC is deactivated.
6. The method of claim 1 , wherein the UE activates a secondary CC (SCC), the activation involves:
activating the SCC before a predefined time;
staring a deactivation timer associated with the SCC; and
triggering a power headroom reporting (PHR) procedure associated with the SCC.
7. The method of claim 1 , wherein the UE deactivates a secondary CC (SCC), the deactivation involves:
deactivating the SCC before a predefined time;
stopping a deactivation timer associated with the SCC; and
flushing all Hybrid ARQ (HARQ) buffers associated with the SCC.
8. A method comprising:
receiving an activation or deactivation command for one or more component carriers (CCs) by a user equipment (UE) in a wireless communication network, wherein the one or more CCs are initialized;
deriving a plurality of instructions corresponds to the one or more CCs based on the command, wherein the UE activates a CC if and only if a current state of the CC is deactivated and a corresponding instruction is for activation, wherein the UE deactivates the CC if and only if the current state of the CC is activated and a corresponding instruction is for deactivation, and wherein the UE does not change the current state of the CC otherwise; and
transmitting feedback information in respond to the command based on an activation or deactivation status, wherein the activation status indicates the CC is activated and the deactivation status indicates the CC is deactivated.
9. The method of claim 8 , wherein the command is contained in a media access control (MAC) control element (CE), and wherein each bit is associated with an activation or deactivation instruction for a corresponding CC.
10. The method of claim 8 , further comprising:
starting an deactivation timer for a secondary CC (SCC) based on a set of predefined events; and
deactivating the SCC when the deactivation timer expires.
11. The method of claim 10 , wherein the set of predefined events comprises at least one of a secondary CC is activated, a downlink assignment is received, an uplink grant is received, a configured transmission takes place, and an activation command is received.
12. The method of claim 8 , wherein the UE activates a secondary CC (SCC), the activation involves:
activating the SCC before a predefined time;
staring a deactivation timer associated with the SCC; and
triggering a power headroom reporting (PHR) procedure associated with the SCC.
13. The method of claim 8 , wherein the UE deactivates a secondary CC (SCC), the deactivation involves:
deactivating the SCC before a predefined time;
stopping a deactivation timer associated with the SCC; and
flushing all Hybrid ARQ (HARQ) buffers associated with the SCC.