  This paper proposes a novel media access control (MAC) mechanism, called the
robust preamble-based MAC mechanism (R-PMAC), which can be applied to power
line communication (PLC) networks in the context of the Industrial Internet of
Things (IIoT). Compared with other MAC mechanisms such as P-MAC and the MAC
layer of IEEE1901.1, R-PMAC has higher networking speed. Besides, it supports
whitelist authentication and functions properly in the presence of data frame
loss. Firstly, we outline three basic mechanisms of R-PMAC, containing precise
time difference calculation, preambles generation and short ID allocation.
Secondly, we elaborate its networking process of single layer and multiple
layers. Thirdly, we illustrate its robust mechanisms, including collision
handling and data retransmission. Moreover, a low-cost hardware platform is
established to measure the time of connecting hundreds of PLC nodes for the
R-PMAC, P-MAC, and IEEE1901.1 mechanisms in a real power line environment. The
experiment results show that R-PMAC outperforms the other mechanisms by
achieving a 50% reduction in networking time. These findings indicate that the
R-PMAC mechanism holds great potential for quickly and effectively building a
PLC network in actual industrial scenarios.
