BIT ALLOCATION OF WWAN SCALABLE H.264 VIDEO MULTICAST FOR HETEROGENEOUS COOPERATIVE PEER-TO-PEER COLLECTIVE

By exploiting multiple network interfaces on one device, e.g., Wireless Wide Area Network (WWAN) and Wireless Local Area Network (WLAN), peers receiving different subsets of WWAN broadcast/multicast packets can perform Cooperative Peer-to-peer Repair (CPR) by exchanging received WWAN packets with their local WLAN peers. This effectively improves the transmission success from a WWAN broadcast/multicast source to a CPR collective. In this paper, we propose an intelligent joint source/channel bit allocation scheme for WWAN scalable video multicast that leverages on the CPR paradigm. Key observation is that given a peer can successfully receive a packet either from the WWAN channel directly, or via a CPR neighbor using ad-hoc WLAN connections, more bits can be redistributed from channel to source coding out of a fixed WWAN bit budget to further minimize peer’s expected visual distortion. In our proposal, groups of peers requiring different video resolutions are assigned to the same multicast group, and we perform one WWAN resource allocation and subsequent CPR over heterogeneous peers of different resolutions together. Our simulations show that our joint multicast group optimization can improve video quality by up to 2.84 dB, compared to a scheme where both WWAN resource allocation and WLAN CPR are separately performed for heterogeneous peers. 1