Terminal redirection

1 . A user equipment (UE), comprising:

at least one processor; and

at least one non-transitory memory storing instructions that, when executed with the at least one processor, cause the UE to:

in response to the UE being in a radio resource control (RRC) inactive state:

store a plurality of user equipment contexts for the UE, wherein each context of the plurality of user equipment contexts corresponds to a different radio access technology (RAT) or a different frequency range of same RAT as the UE;

transmit an RRC connection resume request to a first radio access node, wherein the RRC connection resume request comprises a first indication to the first radio access node that the UE supports resuming an RRC connection with one or more potential target radio access nodes of the different RAT or the different frequency range of the same RAT as the UE, and wherein the first indication comprises validity information of the one or more potential target radio access nodes, the validity information comprising at least one of:

a reference signal received power (RSRP) value, or

a single-bit indication that at least one of the one or more potential target radio access nodes meets a pre-defined criterion; and

receive, from the first radio access node, first instructions to switch to a second radio access node selected from the one or more potential target radio access nodes utilizing the different RAT or the different frequency range of the same RAT as the UE, wherein the first instructions direct the UE to utilize a user equipment context of the plurality of user equipment contexts;

in response to the UE being in an RRC idle state:

transmit an RRC setup request to the first radio access node, wherein the RRC setup request comprises a second indication that the UE supports establishing an RRC connection with a third radio access node of the different RAT or the different frequency range of the same RAT as the UE; and

receive, in one of an RRC setup message or an RRC reconfiguration message, second instructions from the first radio access node to switch to the third radio access node of the different RAT or the different frequency range of the same RAT as the UE;

subsequent to receiving one of the first instructions or the second instructions, perform a random access procedure with the second radio access node or the third radio access node, respectively, wherein the random access procedure comprises transmission of a first random access message (Msg1) and reception of a second random access message (Msg2); and

after completion of the random access procedure, transmit a radio resource control (RRC) complete message comprising one of an RRC Resume Complete message or an RRC Setup Complete message as a fifth message (Msg5), wherein the UE does not transmit a third random access message (Msg3) or a fourth random access message (Msg4) to the second radio access node or the third radio access node.

2 . The UE of claim 1 , wherein, in response to the UE being in the RRC inactive state, the instructions, when executed with the at least one processor, cause the UE further to:

receive the first instructions, to switch to the second radio access node of the different RAT or the different frequency range of the same RAT as the UE, in a RRC resume response message or a RRC release message.

3 . The UE of claim 1 , wherein the instructions, when executed with the at least one processor, cause the apparatus further to:

receive, from a network node, instructions to measure frequencies for available capacity;

in response to the received instructions, perform one or more measurements of the frequencies for the available capacity to generate measurement results; and

include the generated measurement results as a part of the validity information transmitted in the RRC connection resume request.

4 . An apparatus in a communication system, comprising:

at least one processor; and

at least one non-transitory memory storing instructions that, when executed with the at least one processor, cause the apparatus to:

in response to receiving, from a user equipment in a radio resource control (RRC) inactive state, an RRC connection resume request:

receive, from the user equipment, a first indication associated with the RRC connection resume request, wherein the first indication indicates that the user equipment supports resuming an RRC connection with one or more potential target radio access nodes of a different radio access technology (RAT) or a different frequency range of same RAT as the apparatus, the first indication comprising validity information of the one or more potential target radio access nodes, the validity information including at least one of:

a reference signal received power (RSRP) value, or

a single-bit indication that at least one of the one or more potential target radio access nodes meets a pre-defined criterion;

in response to the received first indication, determine that the apparatus is unable to serve the user equipment;

transmit a first redirection request to a second radio access node selected from the one or more potential target radio access nodes;

in response to the transmitted first redirection request, receive a first redirection response from the second radio access node; and

based on the determination and the first redirection response, transmit, to the user equipment, first instructions to switch to the second radio access node, wherein the first instructions direct the user equipment to utilize a user equipment context stored at the user equipment, the user equipment context corresponding to the different RAT or the different frequency range of the second radio access node; and

in response to receiving, from the user equipment in an RRC idle state, an RRC setup request:

receive, from the user equipment, a second indication that the user equipment supports setup to a third radio access node of a different RAT or a different frequency range within same RAT as the apparatus;

based on the received second indication, determine that the apparatus is unable to serve the user equipment;

transmit a second redirection request to the third radio access node utilizing the different RAT or the different frequency range;

in response to the transmitted second redirection request, receive a second redirection response from the third radio access node; and

based on the determination and the second redirection response, transmit, to the user equipment, second instructions to switch to the third radio access node.

5 . The apparatus of claim 4 , wherein, in response to receiving, from the user equipment in the RRC inactive state, the instructions, when executed with the at least one processor, cause the apparatus further to:

transmit the first instructions, to switch to the second radio access node of the different RAT or the different frequency range within same RAT as the apparatus, in an RRC resume message or an RRC release message.

6 . A method in a user equipment (UE) in a communication system, comprising:

in response to the UE being in a radio resource control (RRC) inactive state:

storing a plurality of user equipment contexts, wherein each context of the plurality of user equipment contexts corresponds to a different radio access technology (RAT) or a different frequency range of same RAT as the UE;

transmitting an RRC connection resume request to a first radio access node, wherein the RRC connection resume request comprises a first indication to the first radio access node that the UE supports resuming an RRC connection with one or more potential target radio access nodes of the different RAT or the different frequency range of the same RAT as the UE, and wherein the first indication comprises validity information of the one or more potential target radio access nodes, the validity information comprising at least one of:

a reference signal received power (RSRP) value, or

a single-bit indication that at least one of the one or more potential target radio access nodes meets a pre-defined criterion; and

receiving, from the first radio access node, first instructions to switch to a second radio access node selected from the one or more potential target radio access nodes utilizing the different RAT or the different frequency range of the same RAT as the UE, wherein the first instructions direct the UE to utilize a user equipment context of the plurality of user equipment contexts; and

in response to the UE being in an RRC idle state:

transmitting an RRC setup request to the first radio access node, wherein the RRC setup request comprises a second indication that the UE supports establishing an RRC connection with a third radio access node of the different RAT or the different frequency range of the same RAT as the UE; and

receiving, in one of an RRC setup message or an RRC configuration message, second instructions from the first radio access node to switch to the third radio access node of the different RAT or the different frequency range of the same RAT as the UE;

subsequent to receiving one of the first instructions or the second instructions, performing a random access procedure with the second radio access node or the third radio access node, respectively, wherein the random access procedure comprises transmission of a first random access message (Msg1) and reception of a second random access message (Msg2); and

after completion of the random access procedure, transmitting a radio resource control (RRC) complete message comprising one of an RRC Resume Complete message or an RRC Setup Complete message as a fifth message (Msg5), wherein the UE does not transmit a third random access message (Msg3) or a fourth random access message (Msg4) to the second radio access node or the third radio access node.

7 . A method in an apparatus in a communication system, comprising:

in response to receiving, from a user equipment in a radio resource control (RRC) inactive state, an RRC connection resume request:

receiving, from the user equipment, an first indication associated with the RRC connection resume request, wherein the first indication indicates that the user equipment supports resuming an RRC connection with one or more potential target radio access nodes of a different radio access technology (RAT) or a different frequency range of same RAT as the apparatus, the first indication comprising validity information of the one or more potential target radio access nodes, the validity information including at least one of:

a reference signal received power (RSRP) value, or

a single-bit indication that at least one of the one or more potential target radio access nodes meets a pre-defined criterion;

in response to the received first indication, determining that the apparatus is unable to serve the user equipment;

transmitting a first redirection request to a second radio access node selected from the one or more potential target radio access nodes;

in response to the transmitted first redirection request, receiving a first redirection response from the second radio access node; and

based on the determination and the first redirection response, transmitting, to the user equipment, first instructions to switch to the second radio access node, wherein the first instructions direct the user equipment to utilize a user equipment context stored at the user equipment, the user equipment context corresponding to the different RAT or the different frequency range of the second radio access node; and

in response to receiving, from the user equipment in an RRC idle state, an RRC setup request:

receiving, from the user equipment, a second indication that the user equipment supports setup to a third radio access node of a different RAT or a different frequency range within same RAT as the apparatus;

based on the received second indication, determining that the apparatus is unable to serve the user equipment;

transmitting a second redirection request to the third radio access node utilizing the different RAT or the different frequency range:

in response to the transmitted second redirection request, receive a second redirection response from the third radio access node; and

based on the determination and the second redirection response, transmitting, to the user equipment, second instructions to switch to the third radio access node.