Chorus: Collision Resolution for Efficient Wireless Broadcast

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Traditional wireless broadcast protocols rely heavily on the 802.11-based CSMA/CA model, which avoids interference and collision by conservatively scheduling transmissions. While CSMA/CA is amenable to multiple concurrent unicasts, it tends to degrade broadcast performance, especially when there are a large number of nodes and links are lossy. In this paper, the authors propose a new, drastically different protocol called Chorus that improves the efficiency and scalability of broadcast service with a MAC layer that allows packet collisions. Chorus is built upon the observation that packets carrying the same data can be effectively detected and decoded, even when they overlap in time and have comparable signal strength.