MAC multiplexing and TFC selection procedure for enhanced uplink
A method implemented in a wireless communication system including a wireless transmit/receive unit (WTRU), a Node-B and a radio network controller (RNC) for quantizing multiplexed data allowed by grants to closely match a selected enhanced uplink transport format combination (E-TFC) transport block size is disclosed. The amount of scheduled and non-scheduled data allowed to be transmitted is quantized so that the amount of data multiplexed into an enhanced uplink (EU) medium access control (MAC-e) protocol data unit (PDU) more closely matches the selected E-TFC transport block size. In an embodiment, the amount of buffered data allowed to be multiplexed by at least one grant, (a serving grant and/or a non-serving grant), is quantized so that the sum of scheduled and non-scheduled data including MAC header and control information multiplexed into a MAC-e PDU more closely matches the selected E-TFC transport block size.
1. A method for multiplexing data for an enhanced dedicated channel (E-DCH), the method comprising:
determining a first size of data associated with a serving grant, wherein the serving grant is associated with at least one dedicated channel medium access control (MAC-d) flow;
determining a second size of data associated with at least one non-scheduled grant by summing for each MAC-d flow associated with the at least one non-scheduled grant a size of its non-scheduled grant or a size of its available data;
determining a first sum of the first size of data, the second size of data, and a size of scheduling information;
multiplexing bits from the MAC-d flows and the scheduling information into a medium access control E-DCH (MAC-e) protocol data unit (PDU) having a size not greater than a largest enhanced dedicated channel transport format combination (E-TFC) that does not exceed the first sum, wherein the MAC-d flows are associated with at least one of the serving grant and the at least one non-scheduled grant;
selecting an E-TFC for transmission of the MAC-e PDU, wherein the E-TFC supports the size of the multiplexed bits and does not exceed the first sum; and
transmitting the MAC-e PDU.
2. The method of claim 1 wherein a maximum MAC-e PDU size is equivalent to a largest supported E-TFC size, on a condition that the largest supported E-TFC size is less than or equal to the first sum, wherein the largest supported E-TFC size is based a power offset.
3. The method of claim 1 wherein the multiplexing bits from the MAC-d flows and the scheduling information comprises:
in order of logical channel priority, multiplexing MAC-d flows associated with the at least one non-scheduled grant for transmission up to the second size of data.
4. The method of claim 1 wherein the multiplexing bits from the MAC-d flows and the scheduling information comprises:
in order of logical channel priority, multiplexing MAC-d flows associated with the serving grant for transmission up to the first size of data.
5. The method of claim 4 wherein a number of bits permitted to be multiplexed for a serving grant is derived by subtracting from a size of the selected E-TFC a permitted number of bits for the at least one non-scheduled grant and the scheduling information.
6. The method of claim 1 wherein padding is multiplexed into the MAC-e PDU so that the resulting MAC-e PDU size matches the size of the selected E-TFC.
7. The method of claim 6 wherein a size of the padding is less than a size of a MAC-d flow.
8. The method of claim 1 wherein the selected E-TFC is a smallest E-TFC that supports the size of the multiplexed bits and does not exceed the first sum.
9. A wireless transmit/receive unit (WTRU) comprising:
circuitry configured to determine a first size of data associated with a serving grant, wherein the serving grant is associated with at least one dedicated channel medium access control (MAC-d) flow, and a second size of data associated with at least one non-scheduled grant by summing for each MAC-d flow associated with the at least one non-scheduled grant a size of its non-scheduled grant or a size of its available data, and to determine a first sum of the first size of data, the second size of data, and a size of scheduling information;
a multiplexing device configured to multiplex bits from the MAC-d flows and the scheduling information into a medium access control enhanced dedicated channel (MAC-e) protocol data unit (PDU) having a size not greater than a largest enhanced dedicated channel transport format combination (E-TFC) that does not exceed the first sum, wherein the MAC-d flows are associated with at least one of the serving grant and the at least one non-scheduled grant;
an E-TFC selection device configured to select an E-TFC for transmission of the MAC-e PDU, wherein the E-TFC supports the size of the multiplexed bits and does not exceed the first sum; and
a physical layer device configured to transmit the MAC-e PDU.
10. The WTRU of claim 9 wherein a maximum MAC-e PDU size is equivalent to a largest supported E-TFC size, on a condition that the largest supported E-TFC size is less than or equal to the first sum, wherein the largest supported E-TFC size is based on a power offset.
11. The WTRU of claim 9 wherein the multiplexing device is configured to multiplex bits from the MAC-d flows and the scheduling information in order of logical channel priority, multiplexing MAC-d flows associated with the at least one non-scheduled grant up to the second size of data.
12. The WTRU of claim 9 wherein the multiplexing device is configured to, in order of logical channel priority, multiplex MAC-d flows associated with the sewing grant for transmission up to the first size of data.
13. The WTRU of claim 12 wherein the multiplexing device is configured such that a number of bits permitted to be multiplexed for a serving grant is derived by subtracting from a size of the selected E-TFC a permitted number of bits for the at least one non-scheduled grant and the scheduling information.
14. The WTRU of claim 9 wherein the multiplexing device is configured to multiplex padding into the MAC-e PDU so that the resulting MAC-e PDU size matches the size of the selected E-TFC.
15. The WTRU of claim 14 wherein a size of the padding is less than a size of a MAC-d flow.
16. The WTRU of claim 9 wherein the selected E-TFC is a smallest E-TFC that supports the size of the multiplexed bits and does not exceed the first sum.