Jun-Hyuk Song

Relative time based MBSFN content synchronization

In LTE, enhanced MBMS (eMBMS) allows the combining of MBMS transmission from tightly synchronized cells, in a technique known as Multimedia Broadcast Single Frequency Network (MBSFN). In MBSFN transmission, all eNodeBs in a given MBSFN area must have the radio frames transmitted with the same physical symbol timing. With use of the Extended Cyclic Prefix and the Synchronization Protocol(SYNC) running between the BM-SC (Broadcast/Multicast Service Center) and eNB(eNodeB), it is possible to synchronize content transmission from multiple eNBs. The synchronization protocol layer in BM-SC shall set Time Stamp value that indicates the relative time value of the synchronization sequence. This paper investigates how eNodeB can ensure synchronized MBSFN content transmission with the use of common relative time reference.

Emergency group call over eMBMS

In the event of an emergency, inter-agency collaboration is critical to prevent incidents that can further endanger the public. Our paper proposes the emergency group call over Long Term Evolution (LTE) Evolved Multimedia Broadcast Multicast Service (eMBMS). Current LTE eMBMS specification provides a mechanism for downlink video content delivery and file transmission only. We worked on a novel design for enhancing the current emergency group call network based on the eMBMS solution. Following features are technically further enhanced in our work to provide adequate emergency group services: Multimedia Broadcast Single Frequency Network (MBSFN) architecture, privacy, MBSFN area allocation, service continuity and reduced eMBMS call setup time.