METHOD AND APPARATUS FOR RECEIVING PC5 SIGNAL MESSAGE IN WIRELESS COMMUNICATION SYSTEM

Methods and apparatus for PC5 signaling message reception are disclosed. An inter-UE relay receives a first PC5 signaling message from a first UE on a first sidelink signal radio bearer, where the first PC5 signaling message is used to establish a first sidelink security between the inter-UE relay and the first UE, a link identifier associated with a first link between the first user equipment and the inter-user equipment relay is updated, or the first link between the first user equipment and the inter-user equipment relay is modified. The inter-UE relay also delivers the first PC5 signaling message to an upper layer of the inter-UE relay. In addition, the inter-UE relay receives a second PC5 signaling message from the first UE on a second sidelink signal radio bearer, where the second PC5 signaling message is used to establish a second sidelink security between the first UE and the second UE, a link identifier associated with a second link between the first user equipment and the second user equipment is up