Cognitive flow control based on channel quality conditions
A system and method which improve the performance of a wireless transmission system by intelligent use of the control of the flow of data between a radio network controller (RNC) and a Node B. The system monitors certain criteria and, if necessary, adaptively increases or decreases the data flow between the RNC and the Node B. This improves the performance of the transmission system by allowing retransmitted data, signaling procedures and other data to be successfully received at a faster rate, by minimizing the amount of data buffered in the Node B. Flow control is exerted to reduce buffering in the Node B upon degradation of channel qualities, and prior to a High Speed Downlink Shared Channel (HS-DSCH) handover.
1. A method of downlink flow control of a Node B, the method comprising:
a Node B determining a downlink channel condition between the Node B and a user equipment (UE) wherein the downlink channel condition is determined from a channel quality metric received from the UE on an uplink channel between the Node B and the UE, the numbers of positive acknowledgements (ACKs) and negative acknowledgements (NACKs) from the UE, and the number of protocol data units (PDUs) for the UE buffered in the Node B; and
the Node B sending a message to a radio network controller (RNC) to increase a data rate for the UE in response to an improved channel condition and to decrease the data rate for the UE in response to a degraded channel condition.
2. A Node B configured to perform flow control, the Node B comprising:
a buffer for storing a packet received from a radio network controller (RNC); and
a controller configured to determine a downlink channel condition between the Node B and a user equipment (UE), wherein the downlink channel condition is determined from a channel quality metric received from the UE on an uplink channel between the Node B and the UE, the number of positive acknowledgements (ACKs) and negative acknowledgements (NACKs) from the UE, and the number of protocol data units (PDUs) for the UE buffered in the Node B, and to send a message to the RNC, to increase a data rate for the UE in response to an improved channel condition and to decrease the data rate for the UE in response to a degraded channel condition.