  Wireless blockchain network is proposed to enable a decentralized and safe
wireless networks for various blockchain applications. To achieve blockchain
consensus in wireless network, one of the important steps is to broadcast new
block using wireless channel. Under wireless network protocols, the block
transmitting will be affected significantly. In this work, we focus on the
consensus process in blockchain-based wireless local area network (B-WLAN) by
investigating the impact of the media access control (MAC) protocol, CSMA/CA.
With the randomness of the backoff counter in CSMA/CA, it is possible for
latter blocks to catch up or outpace the earlier one, which complicates
blockchain forking problem. In view of this, we propose mining strategies to
pause mining for reducing the forking probability, and a discard strategy to
remove the forking blocks that already exist in CSMA/CA backoff procedure.
Based on the proposed strategies, we design Block Access Control (BAC)
approaches to effectively schedule block mining and transmitting for improving
the performance of B-WLAN. Then, Markov chain models are presented to conduct
performance analysis in B-WLAN. The results show that BAC approaches can help
the network to achieve a high transaction throughput while improving block
utilization and saving computational power. Meanwhile, the trade-off between
transaction throughput and block utilization is demonstrated, which can act as
a guidance for practical deployment of blockchain.
