Method and system for handling radio link failure in multi-rat dual connectivity system

A method for handling Radio Link Failure (RLF) in a Multiple Radio Access Technology (Multi-RAT) Dual Connectivity (MRDC) system including a User Equipment (UE) connected to a Master Node (MN) and at least one Secondary Node (SN), the method comprising:

• detecting, by the MN, an RLF with the UE;
• after detecting the RLF with the UE, preserving, by the MN, a context of the UE for a particular time period;
• determining, by the MN, whether an SN termination condition for terminating a connection between the UE and an SN of the at least one SN is met, wherein the SN termination condition comprises receiving a Radio Resource Control (RRC) release message related to the SN at the UE;
• continuing, by the MN, data activity with the SN until the SN termination condition is met, in response to determining that the SN termination condition is not met;
• and
• stopping, by the MN, the data activity with the SN, in response to determining that the SN termination condition is met,
• wherein after the UE detecting the RLF with the MN, the UE initiated an RRC connection re-established procedure for the MN and a first timer related to the RRC connection re-established procedure for the MN,
• wherein the MN maintains context of the UE for a time period longer than a duration of the first timer, after detecting the RLF with the UE.

A User Equipment (UE) for handling Radio Link Failure (RLF) in a Multiple Radio Access Technology (Multi-RAT) Dual Connectivity (MRDC) system including a Master Node (MN) and at least one Secondary Node (SN), the UE comprising:

• a transceiver;
• and
• at least one processor coupled to the transceiver, wherein the at least one processor is configured to:
• detect an RLF with the MN,
• after detecting the RLF with the MN, determine whether an SN termination condition for terminating a connection with an SN of the at least one SN is met, wherein the SN termination condition comprises receiving a Radio Resource Control (RRC) release message related to the SN at the UE,
• after detecting the RLF with the MN, initiate a first timer and an RRC connection re-established procedure for the MN,
• maintain the connection with the SN, in response to determining that the SN termination condition is not met, and
• release the connection with the SN, in response to determining that the SN termination condition is met the first timer being expired,
• wherein context of the UE is maintained by the MN for a time period linger than a duration of the first timer, after detection of the RLF with the MN.

A Master Node (MN) for handling Radio Link Failure (RLF) in a Multiple Radio Access Technology (Multi-RAT) Dual Connectivity (MRDC) system including a User Equipment (UE) connected to the MN and at least one Secondary Node (SN), the MN comprising:

• a transceiver;
• and
• at least one processor coupled to the transceiver, wherein the at least one processor is configured to:
• detect an RLF with the UE,
• after detecting the RLF with the UE, preserve a context of the UE for a particular time period, determine whether an SN termination condition for terminating a connection between the UE and an SN of the at least one SN is met, wherein the SN termination condition comprises receiving a Radio Resource Control (RRC) release message related to the SN at the UE,
• continue data activity with the SN until the SN termination condition is met, in response to determining that the SN termination condition is not met, and
• stop the data activity with the SN, in response to determining that the SN termination condition is met,
• wherein after the UE detecting the RLF with the MN, the UE initiates an RRC connection re-established procedure for the MN and a first timer related to the RRC connection re-established procedure for the MN,
• wherein the MN maintains context of the UE for a time period longer than a duration of the first timer, after detecting the RLF with the UE.