US Patent No. 9,357,573

METHOD OF PROVIDING SERVICE CONTINUITY BETWEEN CELLULAR COMMUNICATION AND DEVICE TO-DEVICE COMMUNICATION


Patent No. 9,357,573
Issue Date May 31, 2016
Title Method Of Providing Service Continuity Between Cellular Communication And Device To-device Communication
Inventorship You Sun Hwang, Seoul (KR)
Kwang Ryul Jung, Daejeon (KR)
Mi Jeong Yang, Daejeon (KR)
Hyung Deug Bae, Daejeon (KR)
Soon Yong Lim, Daejeon (KR)
Moon Soo Jang, Daejeon (KR)
Hyeong Jun Park, Daejeon (KR)
Nam Hoon Park, Daejeon (KR)
Assignee Electronics and Telecommunications Research Institute, Daejeon (KR)

Claim of US Patent No. 9,357,573

1. A method of switching communication from cellular communication to device-to-device (D2D) communication comprising:
(a) transferring, by a gateway, a D2D bearer creation request message to a mobility management entity (MME);
(b) creating, by the MME, a D2D bearer identifier (ID) and transferring a D2D bearer setup request message based on the D2D
bearer creation request message and including the D2D bearer ID to a base station;

(c) mapping, by the base station, D2D bearer quality of service (QoS) to D2D radio bearer QoS, and transmitting a radio resource
control (RRC) connection reconfiguration message to terminals;

(d) receiving, by the base station, an RRC connection reconfiguration completion message indicating creation of a D2D radio
bearer from the terminals;

(e) transmitting, by the base station, a D2D bearer creation response message indicating creation of a D2D bearer to the MME;
and

(f) transferring, by the MME, the D2D bearer creation response message to the gateway,
wherein in step (b), the MME generates a proximity service management request message in a non-access stratum (NAS) level,
includes the proximity service management request message in the D2D bearer creation request message, and transmits the resultant
message to the base station,

wherein the proximity service management request message includes a pair identifier, an International Mobile Subscriber Identity
(IMSI), the D2D bearer ID, the D2D bearer QoS, D2D bearer traffic flow template (TFT), and the cellular switchback evolved
packet system (EPS) bearer ID (SBI), and

wherein the SBI is a bearer used for switchback from the D2D communication to the cellular communication.