Traffic distribution method through multi-access network in a network and network entity performing the same

A method for modifying a packet data unit (PDU) session in a network, the method comprising:

• establishing a multi-access PDU session (MA PDU session) for an ATSSS (access traffic steering, switching, and splitting) function;
• transmitting, by an user equipment (UE), a PDU session modification request message including an ATSSS preference, which is a preference for an ATSSS rule, to an access and mobility management function (AMF) when the UE desires to change the ATSSS rule corresponding to the established MA PDU session;
• transmitting, by the AMF, a first message including the ATSSS preference to a session management function (SMF);
• and
• transmitting, by the SMF, a second message including a changed ATSSS rule corresponding to the ATSSS preference to AMF.

A network entity that controls modification for a packet data unit (PDU) session in a network, the network entity comprising:

• a processor controlling a change to an ATSSS (access traffic steering, switching, and splitting) rule corresponding to an established multi-access PDU session (MA PDU session) when the MA PDU session is established in user equipment (UE);
• and
• a network interface transmitting a PDU session modification request message including an ATSSS preference for the ATSSS rule to another network entity,
• wherein the ATSSS preference is a preference derived by the UE for changing the ATSSS rule.