Method and device which minimize interrupt during handover in integrated access backhaul system and which are for first connection in multiple mobile terminals
The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services.
1 . A method performed by an integrated access and backhaul (IAB) node in a wireless communication system, the method comprising:
receiving, from a source IAB node, a control message for handover including default uplink configuration information, wherein the default uplink configuration information includes an uplink routing identifier, a backhaul radio link control (RLC) channel, and an available timer associated with a target IAB node;
generating a medium access control (MAC) entity for the target IAB node based on the received control message;
establishing a logical channel and an RLC entity for the target IAB node;
reconfiguring a backhaul adaptation protocol (BAP) entity for the target IAB node, wherein the BAP entity is associated with the RLC entity configured for the target IAB node;
performing a random access procedure to the target IAB node;
receiving, from a target donor node, a message including a backhaul mapping configuration;
adding a downlink routing identifier based on the backhaul mapping configuration; and
replacing the uplink routing identifier and the backhaul RLC channel based on the backhaul mapping configuration.
2 . The method of claim 1 , wherein the source IAB node transmits a message including an indication of triggered handover type to the target IAB node.
3 . The method of claim 1 , further comprising in case that the random access procedure fails:
falling back to a configuration for the source IAB node; and
resuming a connection with the source IAB node.
4 . The method of claim 1 , wherein the handover is configured for each backhaul RLC channel.
5 . The method of claim 1 , wherein a configuration for the BAP entity includes at least one of BAP address, BAP routing configuration, or bearer mapping configuration.
6 . The method of claim 1 , wherein in case that the random access procedure succeeds, the MAC entity delivers an indicator indicating success of random access to the BAP entity.
7 . An integrated access and backhaul (IAB) node comprising:
a transceiver capable of transmitting and receiving at least one signal; and
a controller coupled to the transceiver,
wherein the controller is configured to:
receive, from a source IAB node, a control message for handover,
generate a medium access control (MAC) entity for a target IAB node based on the received control message including default uplink configuration information, wherein the default uplink configuration information includes an uplink routing identifier, a backhaul radio link control (RLC) channel, and an available timer associated with the target IAB node,
establish a logical channel and an RLC entity for the target IAB node,
reconfigure a backhaul adaptation protocol (BAP) entity for the target IAB node, the BAP entity being associated with the RLC entity configured for the target IAB node, and
perform a random access procedure to the target IAB node,
receive, from a target donor node, a message including a backhaul mapping configuration,
add a downlink routing identifier based on the backhaul mapping configuration, and
replace the uplink routing identifier and the backhaul RLC channel based on the backhaul mapping configuration.
8 . The IAB node of claim 7 , wherein the source IAB node transmits a message including an indication of triggered handover type to the target IAB node.
9 . The IAB node of claim 7 , wherein in case that the random access procedure fails, the controller is further configured to fall back to a configuration for the source IAB node and resume a connection with the source IAB node.
10 . The IAB node of claim 7 , wherein the handover is configured for each backhaul RLC channel.
11 . The IAB node of claim 7 , wherein a configuration for the BAP entity includes at least one of BAP address, BAP routing configuration, or bearer mapping configuration.
12 . The IAB node of claim 7 , wherein in case that the random access procedure succeeds, the MAC entity delivers an indicator indicating success of random access to the BAP entity.