Method and apparatus for handling E-RAB switch problem for dual connectivity in wireless communication system
A method and apparatus for handling evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) switch failure for dual connectivity in a wireless communication system is provided. A master evolved NodeB (MeNB) in dual connectivity receives an E-RAB modification confirm message including a list of E-RABs failed to be modified from a mobility management entity (MME). The MeNB may keep old general packet ratio service (GPRS) tunneling protocol (GTP) tunnels for the failed E-RABs, and trigger a secondary eNB (SeNB) release procedure or a SeNB modification procedure for releasing the failed E-RABs. Alternatively, the MeNB may trigger an E-RAB release procedure for releasing the failed E-RABs.
1. A method for handling, by a master evolved NodeB (MeNB) in dual connectivity, evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) switch failure for dual connectivity in a wireless communication system, the method comprising:
receiving an E-RAB modification confirm message including a list of E-RABs failed to be modified from a mobility management entity (MME);
keeping old general packet radio service (GPRS) tunneling protocol (GTP) tunnels for the E-RABs failed to be modified; and
triggering a secondary eNB (SeNB) release procedure or a SeNB modification procedure for releasing secondary cell group (SCG) bearers corresponding to the E-RABs failed to be modified.
2. The method of claim 1 , wherein the E-RAB modification confirm message further includes an indication of keeping the old GTP tunnels for the E-RABs failed to be modified.
3. The method of claim 1 , wherein the E-RAB modification confirm message further includes a cause value for the failure.
4. The method of claim 1 , wherein a user equipment (UE) is connected to both the MeNB and a SeNB in the dual connectivity.
5. The method of claim 1 , further comprising transmitting an E-RAB modification indication message to the MME.
6. The method of claim 5 , wherein the E-RAB modification indication message includes both a list of E-RABs to be modified and a list of E-RABs not to be modified.
7. The method of claim 5 , wherein the E-RAB modification indication message includes an indication of whether a SCG bearer is added to a SeNB or the SCG bearer is taken from the SeNB.
8. A master evolved NodeB (MeNB) configured to handle, in dual connectivity, evolved universal terrestrial radio access network (E-UTRAN) radio access bearer (E-RAB) switch failure for dual connectivity in a wireless communication system, the MeNB comprising:
a transceiver; and
a processor operatively connected to the transceiver and configured to:
receive an E-RAB modification confirm message including a list of E-RABs failed to be modified from a mobility management entity (MME);
keep old general packet radio service (GPRS) tunneling protocol (GTP) tunnels for the E-RABs failed to be modified; and
trigger a secondary eNB (SeNB) release procedure or a SeNB modification procedure for releasing secondary cell group (SCG) bearers corresponding to the E-RABs failed to be modified.
9. The MeNB of claim 8 , wherein the E-RAB modification confirm message further includes an indication of keeping the old GTP tunnels for the E-RABs failed to be modified.
10. The MeNB of claim 8 , wherein the E-RAB modification confirm message further includes a cause value for the failure.
11. The MeNB of claim 8 , wherein a user equipment (UE) is connected to both the MeNB and a SeNB in the dual connectivity.
12. The MeNB of claim 8 , wherein the processor is configured to transmit an E-RAB modification indication message to the MME.
13. The MeNB of claim 12 , wherein the E-RAB modification indication message includes both a list of E-RABs to be modified and a list of E-RABs not to be modified.
14. The MeNB of claim 12 , wherein the E-RAB modification indication message includes an indication of whether a SCG bearer is added to a SeNB or the SCG bearer is taken from the SeNB.