System and method for IP session continuity in device-to-device communication system

A method for supporting, by a packet data network (PDN) gateway (P-GW), device-to-device (D2D) communication using a wireless communication network that includes an evolved node B (eNB), a serving gateway (S-GW), the P-GW, and a PDN, the method comprising:

• establishing, by the P-GW, a first evolved packet system (EPS) bearer to a first user equipment (UE) and a second EPS bearer to a second UE, the first EPS bearer and the second EPS bearer being configured to support D2D communication via the wireless communication network between the first UE and the second UE;
• storing, by the P-GW, in a table, a packet filter including an identifier (ID) of the second EPS bearer and at least one of a source internet protocol (IP) address of the D2D communication or a destination IP address of the D2D communication;
• upon the P-GW receiving a first IP packet from the first UE on the first EPS bearer using the D2D communication via the wireless communication network, mapping, by the P-GW, the received first IP packet to the second EPS bearer using the table;
• transmitting, by the P-GW, the received first IP packet on the second EPS bearer;
• establishing, by the P-GW, a third EPS bearer to the first UE and a fourth EPS bearer to a third UE;
• and
• upon the P-GW receiving a second IP packet from the first UE on the third EPS bearer using the D2D communication via the wireless communication network, mapping, by the P-GW, the received second IP packet to the fourth EPS bearer using the table,
• wherein the first EPS bearer and the second EPS bearer are established while the first UE and the second UE perform D2D communication via a direct communication path.

A first user equipment (UE) apparatus for performing device-to-device (D2D) communication using a wireless communication network that includes an evolved node B (eNB), a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), and a PDN, the first UE apparatus comprising:

• a transceiver configured to perform D2D communication with a second UE via a direct communication path using an allocated internet protocol (IP) address;
• and
• at least one processor configured to:
• while controlling the transceiver to perform the D2D communication via the direct communication path, control to establish a first evolved packet system (EPS) bearer between the first UE and the P-GW, the first EPS bearer being configured to support D2D communication via the wireless communication network,
• determine whether to switch from the D2D communication via the direct communication path to D2D communication via the wireless communication network,
• activate the first EPS bearer based on the determination,
• in response to the activating of the first EPS bearer, communicate a first IP packet through the activated first EPS bearer using D2D communication via the wireless communication network,
• while performing the D2D communication via the direct communication path, establish a second EPS bearer between the first UE and the P-GW, the second EPS bearer being configured to support D2D communication via the wireless communication network,
• wherein the first EPS bearer is used for D2D communication with the second UE, and the second EPS bearer is used for D2D communication with a third UE different from the second UE, and
• wherein the first IP packet that is transmitted through the first EPS bearer, which is established to the P-GW, is not transmitted to the PDN, or the first IP packet that is received through the first EPS bearer, which is established to the P-GW, is not received from the PDN.

A packet data network (PDN) gateway (P-GW) apparatus for supporting device-to-device (D2D) communication using a wireless communication network that includes an evolved node B (eNB), a serving gateway (S-GW), a P-GW, and a PDN, the P-GW apparatus comprising:

• at least one processor configured to:
• establish a first evolved packet system (EPS) bearer to a first user equipment (UE) and a second EPS bearer to a second UE, the first and second EPS bearers being configured to support D2D communication via the wireless communication network between the first UE and the second UE, and
• store, in a table, a packet filter including an identifier (ID) of the second EPS bearer and at least one of a source internet protocol (IP) address of the D2D communication or a destination IP address of the D2D communication;
• and
• a transceiver configured to communicate a first IP packet to/from at least one of the first UE or the second UE under control of the at least one processor,
• wherein, upon the P-GW receiving the first IP packet from the first UE on the first EPS bearer using the D2D communication via the wireless communication network, the at least one processor is further configured to:
• map the received first IP packet to the second EPS bearer using the table, and
• transmit the first IP packet on the second EPS bearer,
• wherein the at least one processor is further configured to:
• establish a third EPS bearer to the first UE and a fourth EPS bearer to a third UE, and
• upon the P-GW receiving a second IP packet from the first UE on the third EPS bearer using the D2D communication via the wireless communication network, map the received second IP packet to the fourth EPS bearer using the table, and
• wherein the first EPS bearer and the second EPS bearer are established while the first UE and the second UE perform D2D communication via a direct communication path.