Timely Updates in Blockchain for UAV-assisted Data Collection Networks

As unmanned aerial vehicles (UAVs) have been widely considered for data collection, the blockchain has been considered as a technology to ensure the data integrity of collected data. However, the usage of the blockchain leads to additional latency for processing the data. Therefore, in this paper, we newly propose and analyze the timely update probability (TUP) to provide novel design insights for timely update in blockchain-enabled UAV-assisted data collection (U-DC) networks. The TUP is defined as the probability that collected data are transferred and appended to the blockchain within the required latency. We first analyze the TUP for the general case, and then derive a closedform expression of the TUP for the special cases. The transaction generation rate is also analyzed to show how the communication performance affects the blockchain performance. We explore the impacts of communication and blockchain parameters on the TUP to provide new insights on the optimal deployment for timely update in blockchain-enabled U-DC networks. We finally explore the timely update throughput (TUT), defined as the total amount of collected and timely appended data to the blockchain ledger per second, and explore the optimal UAV deployments in terms of the TUP and TUT.