Layered video multicast using fractional frequency reuse over wireless relay networks

Nowadays, multimedia services over wireless networks are increasingly popular. With multicast, many mobile stations can join the same video group and share the same radio resource to efficiently increase frequency utilization. However, users may be located at different positions, and so suffer different degrees of path loss and interference, and receive a different signal-to-interference and noise ratio (SINR). Users at the cell-edge receiving a lower SINR may degrade the multicast efficiency. In this article, we propose four schemes that consider fractional frequency reuse (FFR) over relay networks in multi-cells. With FFR, users close to a base station (BS) are given more resources to improve the video quality. An efficient resource allocation scheme is also proposed. Compared to the conventional relay scheme, the proposed schemes can provide over 10% more video layers for all users and give better video quality for users near the BS.