Book excerpt: Modern cellular networks support unicast and multicast video streaming. Streaming over unicast results in high energy saving for mobile devices, but it can only serve a limited number of users. Whereas multicast streaming can serve large number of mobile users, but it increases the energy consumption for mobile devices. We formulate a resource allocation problem that considers both unicast and multicast simultaneously to maximize the average energy saving across all mobile devices and to serve large number of mobile users. We propose efficient algorithms to solve this problem. Our simulation results show that the proposed algorithms: (i) result in high energy saving close to optimal solutions, (ii) serve large number of mobile users compared to that of unicast-only approach, (iii) are more elastic than unicast- and multicast-only approaches, and (iv) lead to higher energy saving as more network resources are allocated to streaming services.