  Due to advantages in security and privacy, blockchain is considered a key
enabling technology to support 6G communications. Practical Byzantine Fault
Tolerance (PBFT) and RAFT are seen as the most applicable consensus mechanisms
(CMs) in blockchain-enabled wireless networks. However, previous studies on
PBFT and RAFT rarely consider the channel performance of the physical layer,
such as path loss and channel fading, resulting in research results that are
far from real networks. Additionally, 6G communications will widely deploy
high-frequency signals such as terahertz (THz) and millimeter wave (mmWave),
while performances of PBFT and RAFT are still unknown when these signals are
transmitted in wireless PBFT or RAFT networks. Therefore, it is urgent to study
the performance of non-ideal wireless PBFT and RAFT networks with THz and
mmWave signals, to better make PBFT and RAFT play a role in the 6G era. In this
paper, we study and compare the performance of THz and mmWave signals in
non-ideal wireless PBFT and RAFT networks, considering Rayleigh Fading (RF) and
close-in Free Space (FS) reference distance path loss. Performance is evaluated
by five metrics: consensus success rate, latency, throughput, reliability gain,
and energy consumption. Meanwhile, we find and derive that there is a maximum
distance between two nodes that can make CMs inevitably successful, and it is
named the active distance of CMs. The research results analyze the performance
of non-ideal wireless PBFT and RAFT networks, and provide important references
for the future transmission of THz and mmWave signals in PBFT and RAFT
networks.
