User equipment (UE) configuration for accessing a target cell in an integrated access and backhaul (IAB) network
Systems, methods, apparatuses, and computer program products for user equipment (UE) configuration for accessing at least one cell are provided. For instance, an IAB donor centralized unit (CU) may transmit configuration information for controlling accessing the at least one cell in a dedicated time period in case an operation and management (O&M) or the CU allocates a new physical layer cell identity (PCI) to a IAB-node serving the UE. The message may be directed to UEs served by the IAB-node. In a second scenario, the message may be directed to the mobile terminal (MT) of an IAB node to configure a target parent cell for the case of backhaul radio link failure (RLF).
1 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to:
receive, from a network node, configuration information for accessing at least one cell, the configuration information comprising one or more identities of the at least one cell, wherein the at least one cell is associated with a dedicated time period defined by a first timer, and the dedicated time period is for accessing exclusively the at least one cell when a failure is detected for a link to a current serving cell of the apparatus;
start the first timer when a failure is detected for the link to the current serving cell of the apparatus; and
attempt to access the at least one cell until expiration of the first timer or until success of the attempt,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
upon expiry of the first timer, start a second timer; and
attempt to access a cell different from the at least one cell prior to expiry of the second timer.
2 . The apparatus according to claim 1 , wherein the apparatus is configured with conditional handover, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus, when attempting to access the at least one cell, at least to:
when a cell of the at least one cell is detectable and the apparatus has a conditional handover configuration for the detected cell, perform the conditional handover to the cell, or
when the cell of the at least one cell is detectable and the apparatus does not have the conditional handover configuration for the detected cell, perform a re-establishment to the cell.
3 . The apparatus according to claim 1 , wherein the apparatus is not configured with conditional handover, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus, when attempting to access the at least one cell, at least to:
when a cell of the at least one cell is detectable, perform a connection re-establishment to the detectable cell.
4 . The apparatus according to claim 1 , wherein the configuration information is received in at least one of:
a broadcast message,
a groupcast message,
a conditional handover message, or
a radio resource control reconfiguration message.
5 . The apparatus according to claim 1 , wherein receiving the configuration information comprises:
receiving the configuration information from an integrated access and backhaul node, or
receiving the configuration information from a source donor centralized unit, or
receiving the configuration information from a target donor centralized unit via the source donor centralized unit.
6 . The apparatus according to claim 1 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
receive a configuration of a third timer related to radio link failure detection; and
disable the third timer when receiving the configuration information.
7 . The apparatus according to claim 1 , wherein the configuration information further comprises a configuration of the first timer.
8 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to:
receive, from a network node, configuration information for accessing at least one cell, the configuration information comprising one or more identities of the at least one cell, wherein the at least one cell is associated with a dedicated time period defined by a first timer, and the dedicated time period is for accessing exclusively the at least one cell when a failure is detected for a link to a current serving cell of the apparatus;
start the first timer when a failure is detected for the link to the current serving cell of the apparatus; and
attempt to access the at least one cell until expiration of the first timer or until success of the attempt,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
start a fourth timer simultaneously with the first timer; and
wherein the attempting to access the at least one cell comprises:
attempting to access the at least one cell after expiry of the fourth timer.
9 . The apparatus according to claim 8 , wherein the apparatus is configured with conditional handover, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus, when attempting to access the at least one cell, at least to:
when a cell of the at least one cell is detectable and the apparatus has a conditional handover configuration for the detected cell, perform the conditional handover to the cell, or
when the cell of the at least one cell is detectable and the apparatus does not have the conditional handover configuration for the detected cell, perform a re-establishment to the cell.
10 . The apparatus according to claim 8 , wherein the apparatus is not configured with conditional handover, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus, when attempting to access the at least one cell, at least to:
when a cell of the at least one cell is detectable, perform a connection re-establishment to the detectable cell.
11 . The apparatus according to claim 8 , wherein the configuration information is received in at least one of:
a broadcast message,
a groupcast message,
a conditional handover message, or
a radio resource control reconfiguration message.
12 . The apparatus according to claim 8 , wherein receiving the configuration information comprises:
receiving the configuration information from an integrated access and backhaul node, or
receiving the configuration information from a source donor centralized unit, or
receiving the configuration information from a target donor centralized unit via the source donor centralized unit.
13 . The apparatus according to claim 8 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
receive a configuration of a third timer related to radio link failure detection; and
disable the third timer when receiving the configuration information.
14 . An apparatus, comprising:
at least one processor; and
at least one memory including computer program code,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to:
receive, from a network node, configuration information for accessing at least one cell, the configuration information comprising one or more identities of the at least one cell, wherein the at least one cell is associated with a dedicated time period defined by a first timer, and the dedicated time period is for accessing exclusively the at least one cell when a failure is detected for a link to a current serving cell of the apparatus;
start the first timer when a failure is detected for the link to the current serving cell of the apparatus; and
attempt to access the at least one cell until expiration of the first timer or until success of the attempt,
wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
start a fourth timer when a failure is detected for a link to the current serving cell; and
wherein starting the first timer comprises:
starting the first timer after expiry of the fourth timer.
15 . The apparatus according to claim 14 , wherein the fourth timer comprises one of:
a timer defining a user-specific time delay, or
a timer defining a time period for re-connecting to the current serving cell.
16 . The apparatus according to claim 14 , wherein the apparatus is configured with conditional handover, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus, when attempting to access the at least one cell, at least to:
when a cell of the at least one cell is detectable and the apparatus has a conditional handover configuration for the detected cell, perform the conditional handover to the cell, or
when the cell of the at least one cell is detectable and the apparatus does not have the conditional handover configuration for the detected cell, perform a re-establishment to the cell.
17 . The apparatus according to claim 14 , wherein the apparatus is not configured with conditional handover, and wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus, when attempting to access the at least one cell, at least to:
when a cell of the at least one cell is detectable, perform a connection re-establishment to the detectable cell.
18 . The apparatus according to claim 14 , wherein the configuration information is received in at least one of:
a broadcast message,
a groupcast message,
a conditional handover message, or
a radio resource control reconfiguration message.
19 . The apparatus according to claim 14 , wherein receiving the configuration information comprises:
receiving the configuration information from an integrated access and backhaul node, or
receiving the configuration information from a source donor centralized unit, or
receiving the configuration information from a target donor centralized unit via the source donor centralized unit.
20 . The apparatus according to claim 14 , wherein the at least one memory and the computer program code are configured to, with the at least one processor, further cause the apparatus at least to:
receive a configuration of a third timer related to radio link failure detection; and
disable the third timer when receiving the configuration information.