Method and apparatus for multiplexing MAC CEs

1 . A method, comprising:

receiving an uplink grant associated with a first retransmission scheme;

selecting one or more first media access control (MAC) control elements (CEs) from a first number of MAC CEs according to the first retransmission scheme, wherein the one or more first MAC CEs are associated with the first retransmission scheme; and

multiplexing the one or more first MAC CEs to a MAC protocol data unit (PDU) associated with the uplink grant.

2 . The method of claim 1 , further comprising:

dividing the first number of MAC CEs into a second number of groups based on a retransmission scheme of each of the first number of MAC CEs.

3 . The method of claim 1 , further comprising:

multiplexing a second MAC CE associated with a second retransmission scheme to the MAC PDU associated with the uplink grant in response to at least one of: the uplink grant has padding bits to accommodate additional MAC CEs; and a priority level of the second MAC CE is higher than a threshold.

4 . The method of claim 1 , further comprising:

transmitting a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme, and (ii) a logical channel priority level associated with the third MAC CE is higher than a threshold.

5 . The method of claim 1 , further comprising:

transmitting a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme and (ii) the third MAC CE requires disabled feedback retransmission scheme.

6 . The method of claim 1 , further comprising:

transmitting a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme; and

cancelling the SR when the third MAC CE is multiplexed to a MAC PDU associated with a suitable uplink grant, wherein the suitable uplink grant is associated with a retransmission scheme aligned with the first retransmission scheme.

7 . The method of claim 1 , further comprising:

transmitting a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme; and

cancelling the SR after an acknowledgement is received for a MAC protocol data unit (PDU) which includes the third MAC CE.

8 . The method of claim 1 , further comprising:

maintaining a buffer status report (BSR) when a BSR MAC CE is multiplexed to a MAC PDU associated with an uplink grant, wherein a second retransmission scheme of the BSR MAC CE is unaligned with the retransmission scheme of the uplink grant; and

cancelling the BSR after one of (i) an acknowledgement is received for a MAC PDU which includes the BSR MAC CE; and (ii) an indication for cancelling the BSR is received.

9 . An apparatus, comprising:

a non-transitory computer-readable medium having stored thereon computer-executable instructions;

a receiving circuitry;

a transmitting circuitry; and

a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry,

wherein the computer-executable instructions cause the processor to:

receive an uplink grant associated with a first retransmission scheme;

select one or more first media access control (MAC) control elements (CEs) from a first number of MAC CEs according to the first retransmission scheme, wherein the one or more first MAC CEs are associated with the first retransmission scheme; and

multiplex the one or more first MAC CEs to a MAC protocol data unit (PDU) associated with the uplink grant.

10 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to divide the first number of MAC CEs into a second number of groups based on a retransmission scheme of each of the first number of MAC CEs.

11 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to:

multiplex a second MAC CE associated with a second retransmission scheme to the MAC PDU associated with the uplink grant when the uplink grant has padding bits to accommodate additional MAC CEs.

12 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to:

multiplex a second MAC CE associated with a second retransmission scheme to the MAC PDU associated with the uplink grant when a priority level of the second MAC CE is higher than a threshold.

13 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to:

transmit a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme, and (ii) a logical channel priority level associated with the third MAC CE is higher than a threshold.

14 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to:

transmit a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme and (ii) the third MAC CE requires disabled feedback retransmission scheme.

15 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to:

transmit a scheduling request (SR) when there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme; and

cancel the SR when the third MAC CE is multiplexed to a MAC PDU associated with a suitable uplink grant, wherein the suitable uplink grant is associated with a retransmission scheme aligned with the first retransmission scheme.

16 . The apparatus of claim 1 , wherein the computer-executable instructions cause the processor to:

transmit a scheduling request (SR) when (i) there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme; and

cancel the SR after an acknowledgement is received for a MAC protocol data unit (PDU) which includes the third MAC CE.

17 . The apparatus of claim 9 , wherein the computer-executable instructions cause the processor to:

maintain a buffer status report (BSR) when a BSR MAC CE is multiplexed to a MAC PDU associated with an uplink grant, wherein a second retransmission scheme of the BSR MAC CE is unaligned with the retransmission scheme of the uplink grant; and

cancel the BSR after one of (i) an acknowledgement is received for a MAC PDU which includes the BSR MAC CE; and (ii) an indication for cancelling the BSR is received.

18 . A base station comprising:

a receiving circuitry;

a transmitting circuitry; and

a processor coupled to the receiving circuitry and the transmitting circuitry, and which causes the base station to:

transmit, to a user equipment (UE), an uplink grant associated with a first retransmission scheme, the first retransmission scheme enabling the UE to select one or more first media access control (MAC) control elements (CEs) from a first number of MAC CEs according to the first retransmission scheme, wherein the one or more first MAC CEs are associated with the first retransmission scheme.

19 . The base station of claim 18 , wherein the first retransmission scheme comprises one or more of:

a feedback-based uplink retransmission scheme;

a non-feedback-based uplink retransmission scheme;

a blind uplink retransmission scheme; and

a bundling uplink retransmission scheme.

20 . The base station of claim 19 , wherein the processor further causes the base station to:

receive a scheduling request (SR) from the UE, the scheduling request transmitted by the UE when there is no uplink grant associated with the first retransmission scheme for a third MAC CE associated with the first retransmission scheme; and

transmit, to the UE, an acknowledgement for a MAC protocol data unit (PDU) which includes the third MAC CE.