  Due to advantages in security and privacy, blockchain is considered a key
enabling technology to support 6G communications. Practical Byzantine Fault
Tolerance (PBFT) is seen as the most applicable consensus mechanism in
blockchain-enabled wireless networks. However, previous studies on PBFT do not
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 millimeter wave (mmWave) and terahertz (THz), while the performance of PBFT
is still unknown when these signals are transmitted in wireless PBFT networks.
Therefore, it is urgent to study the performance of non-ideal wireless PBFT
networks with mmWave and THz siganls, so as to better make PBFT play a role in
6G era. In this paper, we study and compare the performance of mmWave and THz
signals in non-ideal wireless PBFT networks, considering Rayleigh Fading (RF)
and close-in Free Space (FS) reference distance path loss. Performance is
evaluated by consensus success rate and delay. Meanwhile, we find and derive
that there is a maximum distance between two nodes that can make PBFT consensus
inevitably successful, and it is named active distance of PBFT in this paper.
The research results not only analyze the performance of non-ideal wireless
PBFT networks, but also provide an important reference for the future
transmission of mmWave and THz signals in PBFT networks.
