muNet: Harnessing Multiuser Capacity in Wireless Mesh Networks

We present muNet, a wireless mesh network de- sign to harness the multiuser capacity of wireless channels. Traditionally, media access control is designed to schedule one transmission between one sender and one receiver without interference at any given time. However, this design is suboptimal in terms of achieving the multiuser capacity of multi-access wireless channels. Instead, muNet utilizes well-known physical layer-techniques called superposition coding and successive inter- ference cancellation to enable simultainious unicast transmissions from as ingle transmitter to multiple receivers as well as from multiple transmitters to a single receiver. muNet includes the first practicle MAC protocol that leverages such a physical layer and exposes the multiuser capacity to upper layers. It also includes a simple routing protocol that increases simultaneous transmission opportunities for the MAC layer. A proof-of-concept muNet is implemented on the GNU Radio platform. Measurements on the implementation shows that the throughput gains of muNet are significant (up to 93%). We also supplement our experimenta lresults with extensive simulations. Our simulations shwo that muNet can increase the throughput of large, dense wireless mesh networks by up to 176%.