A Multicast Transmission Scheme in Small Cell Networks with Wireless Backhaul

With deployment of small cells, cellular multicast is gaining attractions as it can efficiently deliver large amounts of multimedia data to cellular users. Evolved Multimedia Broadcast Multicast Service (eMBMS) is an efficient broadcast/multicast mechanism to deliver shared content from LTE network to multiple users. It introduces Multimedia Broadcast multicast service Single Frequency Network (MBSFN) for the video sharing among users to guarantee the Quality of Experience (QoE) of users. In MBSFN, each Small cell Base Station (SBS) should determine the appropriate Modulation and Coding Scheme (MCS) for each physical Resource Block (RB), so as to simultaneously maximize the multicast throughput and satisfy the users' experience requirements. However, existing works did not consider the effect of limited wireless backhaul capacity on the multicast throughput. In this paper, we first demonstrate that limited backhaul capacity would affect the system throughput. Then we formulate the problem of MBSFN-based multicast resource allocation with the constraint of limited wireless backhaul capacity. To solve the problem, we develop a near-optimal algorithm. Finally, we conduct extensive simulations to demonstrate that the limited wireless backhaul capacity is important when identifying the optimal multicast resource allocation solution.