SmartGW: Enabling Bandwidth-Efficient Group Watching in Cloud Social TV Systems

Social TV is emerging as a new paradigm to transform the traditional TV viewing experience. The integration of social networks enables a set of salient social features in the TV system, among which group watching is the most attractive one. However, a simple implementation of group watching incurs significant amount of bandwidth cost in a cloud social TV system. In this paper, we propose a group-aware bandwidth management scheme called SmartGW, aiming to minimize the operational cost of the social TV service provider when delivering the group watching service and improve user QoE simultaneously. We formulate the problem into a constrained stochastic optimization problem and exploit the Lyapunov optimization theory to derive the online bandwidth provisioning and allocation strategies. We also conduct extensive trace-driven simulations to verify the effectiveness of our proposed strategies. The results show that SmartGW can cut down bandwidth cost by over 15 % compared with two alternative approaches and improve the user experience at the same time. Our work can provide useful guidelines for social TV service providers to provision their services more effectively.