Method and apparatus for high speed downlink packet access link adaptation
A method of high speed downlink packet access (HSDPA) link adaptation, comprises receiving a channel quality measurement metric over a Measured Results on random access channel (RACH) information element (IE). The link is adapted based upon the received channel quality metric.
1. A method of high speed downlink packet access (HSDPA) link adaptation implemented in a wireless transmit/receive unit (WTRU), comprising:
a WTRU in a Cell_FACH state performing a channel quality metric measurement in synchronization with a discontinuous reception (DRX) cycle configured for Cell_FACH during which the network is not sending data to the WTRU and while the WTRU is configured to receive a high speed downlink shared channel (HS-DSCH) from a network; and
the WTRU transmitting a radio resource control (RRC) message including the channel quality metric measurement, wherein the channel quality metric measurement is included in a Measured Results on random access channel (RACH) information element (IE) of the RRC message.
2. The method of claim 1 wherein the channel quality metric measurement is based on a universal terrestrial radio access (UTRA) carrier received signal strength indication (RSSI) measured in a Cell_FACH state.
3. The method of claim 1 wherein the channel quality metric measurement is based on a Channel Quality Indication (CQI) calculated by a physical layer of the WTRU.
4. The method of claim 1 wherein the channel quality metric measurement is based on a common pilot channel carrier to interference ratio (CPICH C/I).
5. The method of claim 1 wherein the channel quality metric measurement is based on any one of the following factors: received signal code power, total interference, and capability of the WTRU.
6. The method of claim 1 wherein a plurality of channel quality metric measurements are transmitted over the Measured Results on RACH IE.
7. The method of claim 1 wherein a channel quality metric measurement period is matched to a multiple of the DRX cycle.
8. The method of claim 1 further comprising:
performing the channel quality metric measurement at a next opportunity provided by the DRX cycle following an expiration of a measurement period.
9. The method of claim 1 further comprising:
the WTRU performing Inter-frequency or Inter-radio access technology (RAT) measurements.
10. A wireless transmit/receive unit (WTRU), comprising:
a receiver;
a transmitter; and
a processor in communication with the receiver and the transmitter, the processor configured to perform a channel quality metric measurement in a Cell_FACH state in synchronization with a discontinuous reception (DRX) cycle configured for Cell_FACH during which the network is not sending data to the WTRU and while the WTRU is configured to receive a high speed downlink shared channel (HS-DSCH) from a network, and transmit a radio resource control (RRC) message including the channel quality metric measurement, wherein the channel quality metric measurement is included in a Measured Results on random access channel (RACH) information element (IE) of the RRC message.
11. The WTRU of claim 10 wherein the channel quality metric measurement is based on a universal terrestrial radio access (UTRA) carrier received signal strength indication (RSSI) measured in a Cell_FACH state.
12. The WTRU of claim 10 wherein the channel metric measurement is based on any one of the following factors: received signal code power, total interference, and capability of the WTRU.
13. The WTRU of claim 10 wherein the channel quality metric measurement is based on a common pilot channel carrier to interference ratio (CPICH C/I).
14. The WTRU of claim 10 wherein a WTRU channel quality metric measurement period is matched to a multiple of the DRX cycle.
15. The WTRU of claim 10 wherein the processor is further configured to perform the channel quality metric measurement at a next opportunity provided by the DRX cycle following an expiration of a measurement period.
16. The WTRU of claim 10 wherein the channel quality metric measurement is based on a Channel Quality Indication (CQI) calculated by a physical layer of the WTRU.
17. The WTRU of claim 10 wherein a plurality of channel quality metric measurements are transmitted over the Measured Results on RACH IE.