BoX-MACs: Exploiting Physical and Link Layer Boundaries in Low-Power Networking

The authors present two MAC layers for ultra-low-power wireless networking, BoX-MAC-1 and BoX-MAC-2. Leading low-power MACs today reside in a single layer: BMAC exploits only the physical-layer while XMAC utilizes only the link-layer. In contrast, BoX-MAC-1 and BoX-MAC-2 are cross-layer protocols. BoX-MAC-1 incorporates link-layer information into a predominantly physical-layer sampling approach. BoX-MAC-2 combines physical-layer information into a predominantly link-layer packetized approach. Through analysis and experiments on CC2420-based platforms, they find these cross-layer protocols consume up to 40-50% less energy than XMAC and 30% less energy than BMAC under reasonable workloads. Furthermore, BoX-MAC- 2 yields up to 46% more throughput than its XMAC counterpart. Together, BoX-MAC protocols provide a comprehensive set of low-power link-layer primitives for a wide range of network workloads.