EMS: Efficient Multicast Streaming Scheme for Multicasting within Wi-Fi Hotspot

We have discovered two main problems when a multicast sender and multicast receivers are associated with the same AP. First, the multicast sender cannot determine a proper sending rate with the traditional end-to-end rate-adaptation schemes. Second, the multicast sender wastes its power due to the unique characteristics of power saving mode of the IEEE 802.11 standard. We propose efficient multicast streaming (EMS) to solve these problems without modifying the AP and the multicast receivers. With EMS, the multicast sender adapts its sending rate at the application layer and adjusts the sleep cycle at the MAC layer by monitoring multicast packets sent from the AP. Our experimentation and simulation results show that EMS can improve video quality at the receivers and reduce power consumption of the multicast sender significantly.