Method for synchronizing PDCP operations after RRC connection re-establishment in a wireless communication system and related apparatus thereof
A method used in an E-UTRAN for synchronizing PDCP operations after a RRC connection re-establishment procedure with a user equipment (UE) is provided. The method includes: initiating an RRC reconfiguration procedure to resume all radio bearers other than a signaling radio bearer 1 (SRB 1 ) when an RRC connection is re-established; re-transmitting a designated group of PDCP Service Data Units (SDUs) to the UE when a data radio bearer (DRB) mapped on Radio Link Control (RLC) Acknowledged Mode (AM) is resumed.
1. A communication device for synchronizing Packet Data Convergence Protocol (PDCP) operations with another communication device, the communication device comprising:
means for initiating an RRC Reconfiguration procedure to resume a radio bearer other than a signaling radio bearer 1 (SRB 1 ) when an RRC connection is re-established;
means for transmitting a group of PDCP Service Data Units (SDUs) when the radio bearer (RB) is resumed;
means for generating a new base-key (KeNB) corresponding to a Radio Resource Control (RRC) connection re-establishment procedure, and generating a new ciphering key from the new KeNB; and
means for utilizing the new ciphering key to cipher the transmitted PDCP SDUs when the RRC connection is re-established.
2. The communication device of claim 1 , wherein the communication device is an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), and the other communication device is a user equipment (UE), or the communication device is a user equipment (UE), and the other communication device is an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN).
3. A communication device for synchronizing Packet Data Convergence Protocol (PDCP) operations with another communication device, the communication device comprising:
means for resuming a radio bearer other than a signaling radio bearer 1 (SRB 1 ) when an RRC connection is re-established;
means for receiving a group of PDCP Service Data Units (SDUs) transmitted from the other communication device when the radio bearer (RB) is resumed;
means for generating a new base-key (KeNB) corresponding to a Radio Resource Control (RRC) connection re-establishment procedure, and generating a new ciphering key from the new KeNB; and
means for utilizing the new ciphering key to decipher the received PDCP SDUs when the RRC connection is re-established.
4. The communication device of claim 3 , wherein the communication device is an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), and the other communication device is a user equipment (UE), or the communication device is a user equipment (UE), and the other communication device is an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN).
5. A method of synchronizing Packet Data Convergence Protocol (PDCP) operations with a user equipment (UE), the method comprising:
initiating an RRC Reconfiguration procedure to resume a radio bearer other than a signaling radio bearer 1 (SRB 1 ) when an RRC connection is re-established;
transmitting a group of PDCP Service Data Units (SDUs) to the UE when the radio bearer (RB) is resumed;
generating a new base-key (KeNB) corresponding to a Radio Resource Control (RRC) connection re-establishment procedure, and generating a new ciphering key from the new KeNB; and
utilizing the new ciphering key to cipher the transmitted PDCP SDUs when the RRC connection is re-established.
6. A method synchronizing Packet Data Convergence Protocol (PDCP) operations with an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN), the method comprising:
resuming a radio bearer other than a signaling radio bearer 1 (SRB 1 ) when an RRC connection is re-established;
receiving a group of PDCP Service Data Units (SDUs) transmitted from the E-UTRAN when the radio bearer (RB) is resumed;
generating a new base-key (KeNB) corresponding to a Radio Resource Control (RRC) connection re-establishment procedure, and generating a new ciphering key from the new KeNB; and
utilizing the new ciphering key to decipher the received PDCP SDUs when the RRC connection is re-established.
7. The communication device of claim 1 , wherein the radio bearer is a data radio bearer, DRB.
8. The communication device of claim 3 , wherein the radio bearer is a data radio bearer, DRB.
9. The method of claim 5 , wherein the radio bearer is a data radio bearer, DRB.
10. The method of claim 6 , wherein the radio bearer is a data radio bearer, DRB.