Method and apparatus for enhancing RLC for flexible RLC PDU size
Enhancements are provided for the radio link control (RLC) protocol in wireless communication systems where variable RLC packet data unit (PDU) size is allowed. When flexible RLC PDU sizes are configured by upper layers, radio network controller (RNC)/Node B flow control, RLC flow control, status reporting and polling mechanisms are configured to use byte count based metrics in order to prevent possible buffer underflows in the Node B and buffer overflows in the RNC. The enhancements proposed herein for the RLC apply to both uplink and downlink communications.
1. A method for polling comprising:
on a condition that a transmitting entity is configured to support flexible packet data unit size, maintaining, by the transmitting entity, a byte count mechanism, wherein the byte count mechanism maintains a count associated with a number of bytes transmitted from the transmitting entity;
determining, by the transmitting entity, whether or not the count is equal to or exceeds a Poll_Bytes value; and
on a condition that the count is determined by the transmitting entity to be equal to or exceed the Poll_Bytes value, configuring a packet data unit for transmission from the transmitting entity to include a poll.
2. The method of claim 1 , wherein the packet data unit is configured by setting a polling bit in the packet data unit.
3. The method of claim 1 , wherein the packet data unit is an acknowledged mode data packet data unit.
4. The method of claim 1 , wherein the count includes a packet data unit transmitted in an original transmission.
5. The method of claim 1 , wherein the count includes a packet data unit transmitted in an original transmission and a packet data unit transmitted in a retransmission.
6. A transmitting entity configured for polling, the transmitting entity comprising:
a memory; and
a processor, wherein the transmitting entity is configured at least in part to:
on a condition that the transmitting entity is configured to support flexible packet data unit size, maintain a byte count mechanism, wherein the byte count mechanism maintains a count associated with a number of bytes transmitted from the transmitting entity
determine whether or not the count is equal to or exceeds a Poll_Bytes value; and
on a condition that the count is determined to be equal to or exceed the Poll_Bytes value, configure a packet data unit for transmission from the transmitting entity to include a poll.
7. The transmitting entity of claim 6 , wherein the packet data unit is configured by setting a polling bit in the packet data unit.
8. The transmitting entity of claim 6 , wherein the packet data unit is an acknowledged mode data packet data unit.
9. The transmitting entity of claim 6 , wherein the count includes a packet data unit transmitted in an original transmission.
10. The transmitting entity of claim 6 , wherein the count includes a packet data unit transmitted in an original transmission and a packet data unit transmitted in a retransmission.