On the use of the 433 MHz band to improve the energy efficiency of M2M communications

Due to propagation and interference effects at the 2.4 GHz band, Machine-to-Machine (M2M) wireless communications based on the IEEE 802.15.4 standard typically need multi-hop communications to connect end devices with a gateway. Unfortunately, multi-hop transmissions pose some challenges that are not trivial to solve and may slow down the deployment of M2M networks. For this reason, the IEEE 802.15.4f Working Group (WG) is currently defining the specifications of a new physical layer operating at the 433 MHz band, which offers better propagation conditions and suffers from lower interference levels. In this paper, we analyze the energy consumption of single-hop and multi-hop communications at both 433 MHz and 2.4 GHz. We use realistic propagation models and accurate energy consumption models to conduct a comprehensive assessment of the energy performance at the two frequency bands. The results presented in this paper show that operating at 433 MHz instead of 2.4 GHz can significantly reduce the number of hops between the end device and the gateway, which can be translated into a reduction of the overall network energy consumption.