Traffic control device and method in wireless communication system

A radio access network (RAN) congestion awareness function (RCAF) in a wireless communication system, the RCAF comprising:

• a transceiver;
• and
• at least one processor,
• wherein the at least one processor is configured to:
• receive, from a RAN operations, administration and management (OAM) statistical information of a network of the RCAF;
• identify a congested area based on the received statistical information;
• transmit, to a mobility management entity (MME), a message requesting access point name (APN) information of the identified congested area, wherein information on the identified congested area includes identity (ID) of a congested cell within the network of the RCAF;
• receive, from the MME, a message including the APN information of the identified congested area;
• transmit, to a policy and charging rule function (PCRF), a RAN congestion information (RUCI) report message comprising the identified congested area and the APN information of the identified congested area;
• receive, from the PCRF, a RUCI response message;
• and
• transmit, to an access network discovery and selection function (ANDSF), congested area information of the identified congested area,
• wherein the congested area information is used to determine an ANDSF policy for a terminal for the congested area by the ANDSF,
• wherein, in case that a cell ID of a validity area part of the ANDSF policy does not correspond to the ID of the congested cell, the ANDSF policy is updated without updating a routing policy of the ANDSF policy, and
• wherein, in case that the cell ID of a validity area part of the ANDSF policy corresponds to the ID of the congested cell, based on the ID of the congested cell, the routing policy of the ANDSF policy is updated to prevent the terminal from accessing the congested cell.