Method and apparatus for implementing bearer specific changes as part of a connection reconfiguration that impacts the security keys being used
A method and apparatus provides for receiving a first connection reconfiguration message to configure at least one split bearer with a first logicalchannelidentity, terminated in the second cell group. A first security key for communication with the first cell group and a second security key for communication with the second cell group are applied. A second connection reconfiguration message is received, the second connection reconfiguration message including a counter having a count value for deriving a third security key for communication with the second cell group, wherein the third security key that was derived for communication with the second cell group is based on the count value of the received counter. The third security key is applied for communication with the second cell group, while continuing to use the first security key and the first MAC entity for communication with the first cell group, where continuing to use the first MAC entity includes not resetting the first MAC entity.
1. A method in a user equipment configured to communicate with two cell groups including a first cell group and a second cell group, communication with the two cell groups comprising establishment of a first medium access control (MAC) entity and a second MAC entity, the first MAC entity associated with the first cell group and the second MAC entity associated with the second cell group, the method comprising:
receiving a first connection reconfiguration message to configure at least one split bearer with a first logicalchannelidentity, terminated in the second cell group;
applying a first security key for communication with the first cell group and a second security key for communication with the second cell group;
receiving a second connection reconfiguration message, the second connection reconfiguration message including a counter having a count value for deriving a third security key for communication with the second cell group, wherein the third security key that was derived for communication with the second cell group is based on the count value of the received counter; and
applying the third security key for communication with the second cell group, while continuing to use the first security key and the first MAC entity for communication with the first cell group, where continuing to use the first MAC entity includes not resetting the first MAC entity.
2. A method in accordance with claim 1 , wherein the second connection reconfiguration message includes a second logicalchannelidentity for the split bearer, the second logicalchannelidentity to be used for the communication between the user equipment and the second cell group.
3. A method in accordance with claim 2 , wherein when the second connection reconfiguration message is received, the second logicalchannelidentity is used for the communication between the user equipment and the second cell group instead of the first logicalchannelidentity.
4. A method in accordance with claim 2 , wherein after receiving the second reconfiguration message, that includes the second logicalchannelidentity to be used instead of the first logicalchannelidentity, the first MAC entity discards any received packets associated with the first logicalchannelidentity.
5. A method in accordance with claim 2 , wherein the second security key is associated with any bearer having the first logicalchannelidentity, and the third security key is associated with any bearer having the second logicalchannelidentity.
6. A method in accordance with claim 1 , wherein the first reconfiguration message is received from one of the first cell group and the second cell group.
7. A method in accordance with claim 1 , wherein upon applying the third security key for communication with the second cell group, use of the second security key for communication with the second cell group is discontinued.
8. A method in accordance with claim 1 , wherein the count value is incremented and assigned to each packet data unit for communication with the second cell group.
9. A method in accordance with claim 1 , wherein being terminated in the second cell group includes where a packet data convergence protocol (PDCP) entity for the split bearer is located in the second cell group.
10. A method in accordance with claim 1 , wherein not resetting the first MAC entity includes not flushing the associated downlink (DL) and uplink (UL) hybrid automatic repeat request (HARQ) processes.
11. A user equipment configured to communicate with two cell groups including a first cell group and a second cell group, communication with the two cell groups comprising establishment of a first medium access control (MAC) entity and a second MAC entity, the first MAC entity associated with the first cell group and the second MAC entity associated with the second cell group, the user equipment comprising:
a transceiver that receives a first connection reconfiguration message to configure at least one split bearer with a first logicalchannelidentity, terminated in the second cell group; and
a controller that applies a first security key for communication with the first cell group and a second security key for communication with the second cell group;
wherein a second connection reconfiguration message is received by the transceiver, the second connection reconfiguration message including a counter having a count value for deriving a third security key for communication with the second cell group, wherein the third security key that was derived for communication with the second cell group is based on the count value of the received counter; and
wherein the third security key for communication with the second cell group is applied by the controller, while continuing to use the first security key and the first MAC entity for communication with the first cell group, where continuing to use the first MAC entity includes not resetting the first MAC entity.
12. A user equipment in accordance with claim 11 , wherein the second connection reconfiguration message includes a second logicalchannelidentity for the split bearer, the second logicalchannelidentity to be used for the communication between the user equipment and the second cell group.
13. A user equipment in accordance with claim 12 , wherein when the second connection reconfiguration message is received, the second logicalchannelidentity is used for the communication between the user equipment and the second cell group instead of the first logicalchannelidentity.
14. A user equipment in accordance with claim 12 , wherein after receiving the second reconfiguration message, that includes the second logicalchannelidentity to be used instead of the first logicalchannelidentity, the first MAC entity discards any received packets associated with the first logicalchannelidentity.
15. A user equipment in accordance with claim 12 , wherein the second security key is associated with any bearer having the first logicalchannelidentity, and the third security key is associated with any bearer having the second logicalchannelidentity.
16. A user equipment in accordance with claim 11 , wherein the first reconfiguration message is received from one of the first cell group and the second cell group.
17. A user equipment in accordance with claim 11 , wherein upon applying the third security key for communication with the second cell group, use of the second security key for communication with the second cell group is discontinued.
18. A user equipment in accordance with claim 11 , wherein the count value is incremented and assigned to each packet data unit for communication with the second cell group.
19. A user equipment in accordance with claim 11 , wherein being terminated in the second cell group includes where a packet data convergence protocol (PDCP) entity for the split bearer is located in the second cell group.
20. A user equipment in accordance with claim 11 , wherein not resetting the first MAC entity includes not flushing the associated downlink (DL) and uplink (UL) hybrid automatic repeat request (HARQ) processes.