Multimedia Broadcast Multicast Service over Single Frequency Network (MBSFN) in LTE based Femtocell

Abstract

Multimedia Broadcast Multicast Services (MBMS) provides a mechanism to support effective delivery of multimedia traffic over cellular network for all users which request the same multimedia data. It was introduced in 3GPP release 6 and has been developed in recent release in term of enhanced MBMS (eMBMS). Current eMBMS can support two kinds of transmission, namely Single-cell transmission (in this mode the MBMS data only can be transmitted inside one single cell coverage) and Multi-cell transmission (in this mode the MBMS data are sent by different cells that are tightly synchronized), which also known as Single Frequency Network (SFN). In SFN all base stations transmit the same signal at the same time and over the same frequency channel to user equipment. In SFN, the transmissions received from multiple cells will, as seen from the UE, appear as a single transmission subject to severe multipath propagation. SFN can bring benefit whichs changes the interference or destructive signal to constructive signal and contain longer cyclic prefix than conventional transmission. Femtocells are low-power wireless access points that operate in licensed spectrum to connect standard mobile devices to a mobile operator's network using residential DSL or cable broadband connections. Current Macrocells could support indoor coverage but with some limitations caused by thick walls, high locations and other indoor obstacles. Those were a challenges need to be solved and Femtocells offers more efficient solutions to handle indoor coverage. When first introduced, Femtocells can solved the poor quality of indoor voice and data services. When those problems are solved, more services demanded to be supported by Femtocell, e.g. multimedia services.