MultiMAC: A Multiple MAC Network Stack Architecture for TinyOS

Due to the extreme energy requirements often found in sensor networks and the fact that these sensor networks are being used for an increasingly wide variety of applications, there currently exist many different sensor network MAC protocols each optimised for a different set of application requirements. Since these MAC protocols are not compatible with each other, there is generally no interoperability between sensor networks. This lack of interoperability becomes a severe problem when connectivity between sensor networks is required. In this paper, we demonstrate the feasibility of using Virtual Gateways, sensor nodes running multiple MAC protocols simultaneously on top of a single radio interface, to enable connectivity between sensor networks. To this end we have developed MultiMAC, a network stack for TinyOS capable of running multiple MAC protocols at the same time. We show that the architecture of the MultiMAC stack is flexible and extensible enough to support a wide variety of MAC protocols and that the overhead of this network stack is minimal.