System and method for reducing resets during handovers in a single frequency dual carrier wireless communication system
A method, apparatus, and computer program product can provide for procedures at an access terminal for handling the delivery of packets from the MAC entity to the RLC entity, with an aim to reduce the occurrence of RLC resets that might otherwise be caused by out-of-order processing of control packets following a serving cell change. In one example, a MAC entity may insert an identifier into a packet delivered up to the RLC entity, to indicate whether the packet arrived from the current primary serving cell. In another example, a serving cell change procedure may include steps to flush a queue at the MAC entity and kill any running reordering release timers. In these ways potential problems caused by out-of-order control packets can be reduced or avoided.
1. A method of wireless communication operable at an access terminal, comprising:
receiving a packet at a medium access control (MAC) entity from a first serving cell;
delivering the packet to a radio link control (RLC) layer;
inserting an identifier into the packet, the identifier adapted to indicate whether the first serving cell is a current primary serving cell at the time of the delivering of the packet to the RLC layer;
determining at the RLC layer that the packet is a control packet;
determining at the RLC layer that the serving cell is not the primary serving cell; and
discarding the control packet.
2. The method of claim 1 , further comprising:
determining at the MAC entity whether the packet was received from the current primary serving cell at the time of the delivering of the packet to the RLC layer.
3. The method of claim 1 , further comprising:
receiving control signaling for mapping a current primary serving cell to a first base station.
4. The method of claim 3 , wherein the control signaling comprises radio resource control (RRC) signaling provided by a radio network controller (RNC).
5. An access terminal for wireless communication, comprising:
a radio link control (RLC) entity for processing an RLC packet; and
a first medium access control (MAC) entity for receiving a first downlink channel comprising a plurality of MAC packets, reordering the plurality of MAC packets to form the RLC packet, and delivering the RLC packet to the RLC entity,
wherein the first MAC entity is configured to insert into the delivered RLC packet an identifier indicating whether the delivered RLC packet arrived from a serving cell that is a primary serving cell at the time of the delivering the RLC packet to the RLC entity, and
wherein the RLC entity is configured to determine that the RLC packet is a control packet, determine that the serving cell is not the primary serving cell, and discard the control packet.
6. The access terminal of claim 5 , further comprising:
a second MAC entity for receiving a second downlink channel,
wherein the first downlink channel and the second downlink channel are transmitted wirelessly utilizing the same carrier frequency.
7. An access terminal configured for wireless communication, comprising:
at least one processor;
a receiver coupled to the at least one processor for receiving a downlink transmission; and
a memory coupled to the at least one processor,
wherein the at least one processor is configured to:
receive a packet at a medium access control (MAC) entity from a first serving cell;
deliver the packet to a radio link control (RLC) layer;
insert an identifier into the packet, the identifier adapted to indicate whether the first serving cell is a current primary serving cell at the time of the delivering of the packet to the RLC layer;
determine at the RLC layer that the packet is a control packet;
determine at the RLC layer that the serving cell is not the primary serving cell; and
discard the control packet.
8. The access terminal of claim 7 , wherein the at least one processor is further configured to:
determine at the MAC entity whether the packet was received from the current primary serving cell at the time of the delivering of the packet to the RLC layer.
9. The access terminal of claim 7 , wherein the at least one processor is further configured to:
receive control signaling for mapping a current primary serving cell to a first base station.
10. The access terminal of claim 9 , wherein the control signaling comprises radio resource control (RRC) signaling provided by a radio network controller (RNC).
11. An access terminal configured for wireless communication, comprising:
means for receiving a packet at a medium access control (MAC) entity from a first serving cell;
means for delivering the packet to a radio link control (RLC) layer;
means for inserting an identifier into the packet, the identifier adapted to indicate whether the first serving cell is a current primary serving cell at the time of the delivering of the packet to the RLC layer;
means for determining at the RLC layer that the packet is a control packet;
means for determining at the RLC layer that the serving cell is not the primary serving cell; and
means for discarding the control packet.
12. A computer program product operable at an access terminal, comprising:
a non-transitory computer-readable medium comprising:
instructions for causing a computer to receive a packet at a medium access control (MAC) entity from a first serving cell;
instructions for causing a computer to deliver the packet to a radio link control (RLC) layer;
instructions for causing a computer to insert an identifier into the packet, the identifier adapted to indicate whether the first serving cell is a current primary serving cell at the time of the delivering of the packet to the RLC layer;
instructions for causing a computer to determine at the RLC layer that the packet is a control packet;
instructions for causing a computer to determine at the RLC layer that the serving cell is not the primary serving cell; and
instructions for causing a computer to discard the control packet.