  An increasing number of low-power Internet of Things (IoT) devices will be
widely deployed in the near future. Considering the short-range communication
of low-power devices, multi-hop transmissions will become an important
transmission mechanism in IoT networks. It is crucial for lowpower devices to
transmit data over long distances via multihop in a low-delay and reliable way.
Small-world characteristics of networks indicate that the network has an
advantage of a small Average Shortest-path Length (ASL) and a high Average
Clustering Coefficient (ACC). In this paper, a new IoT routing mechanism
considering small-world characteristics is proposed to reduce the delay and
improve the reliability. The ASL and ACC are derived for performance analysis
of small-world characteristics in IoT networks based on Cayley graphs. Besides,
the reliability and delay models are proposed for Small-World IoT based on
Cayley grapHs (SWITCH). Simulation results demonstrate that SWITCH has lower
delay and better reliability than that of conventional Nearest Neighboring
Routing (NNR). Moreover, the maximum delay of SWITCH is reduced by 50.6%
compared with that by NNR.
