Method for performing device to device direct communication, method for supporting the same, and device therefor

A method for performing D2D direct communication by a user equipment (UE) in a wireless communication system, the method comprising:

• transmitting, to a base station, a first message including a D2D connection request and a cellular connection request, the UE operates in an idle state;
• receiving, from the base station, a second message corresponding to a response to the D2D connection request and cellular connection request;
• and
• transmitting a peer discovery signal periodically to at least one neighboring UE according to peer discovery configuration information,
• wherein the second message includes a C-RNTI (cell-radio network temporary identifier) allocated to the UE for connection with the base station, a D2D-RNTI allocated to the UE for D2D direct communication and the peer discovery configuration information,
• wherein the peer discovery configuration information indicates a time slot shift for the UE and a peer discovery channel for the peer discovery signal among a plurality of peer discovery channels, and
• wherein different time slot shifts are applied to peer discovery channels which are mapped on different frequency resources.

A method for supporting D2D direct communication by a base station in a wireless communication system, the method comprising:

• receiving a first message including a D2D connection request and a cellular connection request from a user equipment (UE) operating in an idle state;
• and
• transmitting, to the UE, a second message corresponding to a response to the D2D connection request and cellular connection request,
• wherein the second message includes a C-RNTI allocated to the UE for connection with the base station, a D2D-RNTI allocated to the UE for D2D direct communication and peer discovery configuration information for the UE to transmit a peer discovery signal periodically,
• wherein the peer discovery configuration information indicates a time slot shift for the UE and a peer discovery channel for the peer discovery signal among a plurality of peer discovery channels, and
• wherein different time slot shifts are applied to peer discovery channels which are mapped on different frequency resources.

A user equipment (UE) for performing D2D direct communication in a wireless communication system, the UE comprising:

• a transmitter for transmitting, to a base station, a first message including a D2D connection request for D2D direct communication from the UE, the UE is connected to the base station;
• and
• a receiver for receiving, from the base station, a second message corresponding to a response to the D2D connection request,
• wherein the transmitter is configured to transmit a peer discovery signal periodically to at least one neighboring UE according to peer discovery configuration information,
• wherein the second message includes a D2D-RNTI allocated to the UE for D2D direct communication and the peer discovery configuration information,
• wherein the peer discovery configuration information indicates a time slot shift for the UE and a peer discovery channel for the peer discovery signal among a plurality of peer discovery channels, and
• wherein different time slot shifts are applied to peer discovery channels which are mapped on different frequency resources.

A user equipment (UE) for performing D2D direct communication in a wireless communication system, comprising:

• a transmitter for transmitting, to a base station, a first message including a D2D connection request and a cellular connection request from the UE, the UE operates in an idle state;
• and
• a receiver for receiving, from the base station, a second message corresponding to a response to the D2D connection request and cellular connection request,
• wherein the transmitter is configured to transmit a peer discovery signal periodically to at least one neighboring UE according to peer discovery configuration information,
• wherein the second message includes a C-RNTI allocated to the UE for connection with the base station, a D2D-RNTI allocated to the UE for D2D direct communication and the peer discovery configuration information,
• wherein the peer discovery configuration information indicates a time slot shift for the UE and a peer discovery channel for the peer discovery signal among a plurality of peer discovery channels, and
• wherein different time slot shifts are applied to peer discovery channels which are mapped on different frequency resources.

A base station for supporting D2D direct communication in a wireless communication system, the base station comprising:

• a receiver for receiving a first message including a D2D connection request and a cellular connection request from a user equipment (UE), the UE operates in an idle state;
• and
• a transmitter for transmitting, to the UE, a second message corresponding to a response to the D2D connection request and cellular connection request,
• wherein the second message includes a C-RNTI allocated to the UE for connection with the base station, a D2D-RNTI allocated to the UE for D2D direct communication and peer discovery configuration information for the UE to transmit a peer discovery signal periodically,
• wherein the peer discovery configuration information indicates a time slot shift for the UE and a peer discovery channel for the peer discovery signal among a plurality of peer discovery channels, and
• wherein different time slot shifts are applied to peer discovery channels which are mapped on different frequency resources.