UNAP: User-Centric Network-Aware Push for Mobile Content Delivery

The consumer interest in mobile multimedia content is on the rise, driven by the higher bandwidth of 3G networks and by the availability of low-cost high-resolution mobile devices. However, providing a good user experience remains a challenge due to bandwidth bottlenecks at peak time, channel quality variations and high battery drain incurred by long data transmission times at lower bandwidths. Consequently high jitter, buffering delays and frequent network outages are ever so common for mobile multimedia services. The emerging mobile broadcast networks (e.g. BCMCS, MediaFLO, DVB-H) are well suited for efficient delivery of highly popular content but lack the on-demand, interactive and retransmission (for reliability) capabilities by virtue of being one-way. In addition, due to business reasons (e.g. MediaFLO) or technical reasons (e.g. BCMCS) service providers prefer to deliver only a limited number of popular channels over these networks. In this paper we propose a mobile content delivery architecture that takes wireless specifics into account to enhance the user experience with multimedia services. Our solution makes efficient use of the available bandwidth, does network and channel quality-aware content delivery on the unicast 3G network while at the same time efficiently and reliably schedules content delivery over the mobile broadcast network. In our solution the delivered content is pre-cached on the storage available on the mobile device. This provides a better user experience, reduces the peak load on the network, and reduces the battery drain on the mobile device. Motivated by the proposed architecture we study the problem of scheduling content over a hybrid unicast and broadcast mobile network and design efficient algorithms and heuristics for the problem.