IoT-RF: A Routing Framework for the Internet of Things

Internet Engineering Task Force (IETF) standardized RPL as a routing framework for the Internet of Things (IoT). RPL supports many-to-one, many-to-many, and one-to-many communications. Recent studies demonstrate that RPL performs poorly in many-to-many and one-to-many communications due to the additional control overhead associated with discovering many-to-many and one-to-many forwarding paths and its non storing mode of operation (MoP). In this paper, we present a routing framework for IoT (IoT-RF) that supports many-to-one, many-to-many, and one-to-many communications. The framework works with the storing MoP, and suggests the use of multiple gateways in a network to overcome memory limitations of the storing MoP. Moreover, the framework proposes two protocols to discover many-to-many and one-to-many forwarding paths. One of the proposed protocols discovers many-to-many and one-to-many forwarding paths through many-to-one communication, hence there is no additional control overhead associated with the protocol. The other protocol uses empty control messages to discover many-to-many and one-to-many forwarding paths. We implement our IoT-RF in the Contiki operating system. We evaluate our IoT-RF against a de facto routing framework for IoT using Cooja-based emulation experiments. Our results demonstrate that in many-to-one, many-to-many, and one-to-many communications our IoT-RF significantly outperforms the de facto routing framework in terms of the packet delivery ratio, end-to-end packet delivery delay, and control overhead.