Method of reducing signalling overhead and power consumption in a wireless communication system
A method of transmitting channel quality information (CQI) to an access network (AN) in a system having at least one carrier is disclosed. More specifically, the method includes receiving at least one packet from the AN, each of which includes an indicator, wherein the indicator provides buffer level information and ceasing transmission of the CQI of at least one non-anchor carrier to the AN if the buffer level information indicates that there is no more packet to be transmitted to an access terminal (AT).
1. A method of transmitting channel quality information (CQI) from an access terminal (AT) to an access network (AN) in a system having at least one carrier, the method comprising:
receiving at least one packet from the AN, wherein each of the at least one packet includes an indicator providing buffer level information;
ceasing transmission of CQI on at least one non-anchor carrier to the AN when the buffer level information indicates that there are no more packets to be transmitted to the AT, wherein the AT continues to transmit CQI on at least one anchor carrier to the AN;
receiving an activate indicator on the at least one anchor carrier when the buffer level information indicates that there is at least one packet to be transmitted to the AT, wherein the activate indicator commands the AT to activate the at least one non-anchor carrier; and
starting transmission of the CQI on the at least one non-anchor carrier to the AN, wherein the at least one non-anchor carrier transmits a data packet and the at least one anchor carrier transmits a control packet.
2. The method of claim 1 , wherein the buffer level information is represented by 1 bit.
3. The method of claim 2 , wherein the 1 bit indicates that either there are no more packets to be transmitted to the AT or there are more packets to be transmitted to the AT.
4. The method of claim 1 , wherein the buffer level information is represented by at least 2 bits.
5. The method of claim 4 , wherein the at least 2 bits denotes a number of buffer levels corresponding to the number of bits represented.
6. The method of claim 5 , wherein a number of CQI carrier feedback channels to be used is determined by the AT based on the number of buffer levels.
7. The method of claim 1 , wherein the indicator is a last packet indicator (LPI) which indicates a buffer level for the AT.
8. The method of claim 7 , wherein the buffer level represents whether there are no more packets to be transmitted to the AT or there are more packets to be transmitted to the AT.
9. The method of claim 7 , wherein the LPI is included in a header portion of the packet in a multi-user packet.
10. The method of claim 7 , wherein the LPI is appended at the end of a payload in a multi-user packet.
11. The method of claim 7 , wherein the LPI is in a bitmap format.
12. The method of claim 7 , wherein the LPI is a command.
13. The method of claim 1 , wherein the CQI represents a signal-to-noise ratio measured by the AT.
14. The method of claim 1 , wherein the CQI includes data rate control (DRC) information.
15. A method of transmitting information from an access terminal (AT) to an access network (AN) in a system having at least one cater, the method comprising:
transmitting an acknowledgement (ACK) signal in response to a received packet from the AN;
activating a timer upon transmitting the ACK signal to the AN;
ceasing transmission of channel quality information (CQI) on at least one non-anchor carrier when the timer expires, wherein the AT continues to transmit CQI on at least one anchor cater to the AN;
receiving an activate indicator on the at least one anchor carrier when buffer level information at the AN indicates that there is at least one packet to be transmitted to the AT, wherein the activate indicator commands the AT to activate the at least one non-anchor carrier; and
starting transmission of the CQI on the at least one non-anchor carrier to the AN, wherein the at least one non-anchor carrier transmits a data packet and the at least one anchor carrier transmits a control packet.
16. The method of claim 15 , wherein the CQI includes a data rate control (DRC).
17. A method of transmitting information from an access terminal (AT) to an access network (AN) in a system having at least one carrier, the method comprising:
receiving at least one packet from the AN on at least one carrier, wherein each of the at least one packet includes an indicator which provides buffer level information;
transmitting an acknowledgement (ACK) signal in response to a received packet from the AN;
activating a timer upon transmitting the ACK signal on the at least one carrier;
ceasing transmission of channel quality information (CQI) on at least one non-anchor carrier to the AN when the buffer level information indicates that there are no more packets to be transmitted to the AT or when the timer expires, wherein the AT continues to transmit CQI on at least one anchor cater to the AN;
receiving an activate indicator on the at least one anchor carrier when the buffer level information indicates that there is at least one packet to be transmitted to the AT, wherein the activate indicator commands the AT to activate the at least one non-anchor carrier; and
starting transmission of the CQI on the at least one non-anchor carrier to the AN, wherein the at least one non-anchor carrier transmits a data packet and the at least one anchor carrier transmits a control packet.