TECHNICAL FIELD

The present invention relates to a wireless communication system, and more particularly to a method for performing a path reselection and a device supporting the same.

BACKGROUND ART

A mobile communication system has been developed to provide a voice service while ensuring an activity of a user. However, in the mobile communication system, not only a voice but also a data service is extended. At present, due to an explosive increase in traffic, there is a shortage of resources and users demand a higher speed service, and as a result, a more developed mobile communication system is required.

Requirements of a next-generation mobile communication system should be able to support acceptance of explosive data traffic, a dramatic increase in per-user data rate, acceptance of a significant increase in the number of connected devices, very low end-to-end latency, and high-energy efficiency. To this end, various technologies are researched, which include dual connectivity, massive multiple input multiple output (MIMO), in-band full duplex, non-orthogonal multiple access (NOMA), super wideband support, device networking, and the like.

DISCLOSURE

Technical Problem

An object of the present specification is to provide a method for reselecting a path performing a radio link failure (RLF) recovery procedure when a RLF occurs on a UE-to-UMTS (Uu) link.

Another object of the present specification is to provide a method for reselecting a relaying path based on whether to support a service type, a congestion level of a hop, or the like.

Technical problems to be solved by the present invention are not limited by the technical problems mentioned above, and other technical problems which are not mentioned above can be clearly understood from the following description by those skilled in the art to which the present invention pertains.

Technical Solution

The present specification provides a method for performing, by a first user equipment (UE), a radio link failure (RLF) recovery procedure in a wireless communication system, the method comprising, wherein the first UE is connected to a base station via a UE-to-UMTS (Uu) link and is connected to a second UE via a sidelink, determining a path for performing the RLF recovery procedure when a RLF is detected on the Uu link; and performing an RRC connection re-establishment procedure in order to recover the RLF through the determined path, wherein the path for performing the RLF recovery procedure is determined based on a factor related to data characteristic of the first UE, wherein the determined path is the Uu link or the sidelink.

In the present specification, the factor related to the data characteristic of the first UE is a Qos class identifier (QCI), a packet delay budget, or a priority.

In the present specification, the method further comprises receiving, from the base station, a threshold for the factor related to the data characteristic of the first UE, wherein the path for performing the RLF recovery procedure is determined through a comparison between the factor related to the data characteristic of the first UE and the received threshold.

In the present specification, when the determined path is the sidelink, the RRC connection re-establishment procedure further comprises sending, to the second UE, a request message for requesting a RRC connection re-establishment; and receiving, from the second UE, a response message to the request message.

In the present specification, the first UE is a remote UE, and the second UE is a relay UE.

The present specification provides a method for reselecting, by a first node, a relaying path in a wireless communication system, the method comprising, wherein the first node is connected to a second node via a UE-to-UMTS (Uu) link, transmitting and receiving data with one or more nodes via the Uu link; reselecting the relaying path when a radio link failure (RLF) is detected on the Uu link or a specific condition is met; and transmitting and receiving data with at least one node through the reselected relaying path, wherein the specific condition is whether to support a 5G Qos indicator (5QI) level on a node, whether to support a specific service type on the node, a congestion level of a hop, or a beam state.

In the present specification, the method further comprises, when the relaying path is reselected using a distributed manner, exchanging assistance information with the at least one node.

In the present specification, the assistance information is exchanged periodically or in an event triggered manner.

In the present specification, when the RLF is not detected on the Uu link, the relaying path is reselected depending on the specific condition.

In the present specification, the specific service type is enhanced multimedia broadband (eMBB), ultra reliable low latency communication (URLLC), or massive IoT (MIoT).

In the present specification, the first node is a relay node, and the second node is a donor node. The second node is connected to a 5th generation core network.

The present specification provides a first user equipment (UE) for performing a radio link failure (RLF) recovery procedure in a wireless communication system, the first UE comprising a radio frequency (RF) module configured to transmit and receive a radio signal; and a processor functionally connected to the RF module, wherein the first UE is connected to a base station via a UE-to-UMTS (Uu) link and is connected to a second UE via a sidelink, wherein the processor is configured to determine a path for performing the RLF recovery procedure when a RLF is detected on the Uu link; and perform an RRC connection re-establishment procedure in order to recover the RLF through the determined path, wherein the path for performing the RLF recovery procedure is determined based on a factor related to data characteristic of the first UE, wherein the determined path is the Uu link or the sidelink.

Advantageous Effects

The present specification has an effect capable of implementing transmission and reception of data suitable for 5G requirements by applying parameters related to a service flow considered in a next generation communication system such as 5G as well as RSRP to thereby reselect a path.

Effects obtainable from the present invention are not limited by the effects mentioned above, and other effects which are not mentioned above can be clearly understood from the following description by those skilled in the art to which the present invention pertains.

