| Period | Classless [s] | Low priority [s] | High priority [s] | |
| 1st | (2013/10/1-2014/9/30) | 1060.67797 | 1947.47115 | 1044.25043 |
| 2nd | (2014/10/1-2015/9/30) | 1171.98866 | 4887.56496 | 1070.32818 |
| overall | (2013/10/1-2015/9/30) | 1124.13286 | 3888.06977 | 1059.06133 |
In Bitcoin system, a transaction is given a priority value according to its attributes such as the remittance amount and fee, and transactions with high priorities are likely to be confirmed faster than those with low priorities. In this paper, we analyze the transaction-confirmation time for Bitcoin system. We model the transaction-confirmation process as a queueing system with batch service, M/$ \mbox{G}^B $/1. We consider the joint distribution of numbers of transactions in system and the elapsed service time, deriving the mean transaction-confirmation time. Using the result, we derive the recursive formulae of mean transaction-confirmation times of an M/$ \mbox{G}^B $/1 queue with priority service discipline. In numerical examples, we show the effect of the maximum block size on the mean transaction-confirmation time, investigating the accuracy region of our queueing model. We also discuss how the increase in micropayments, which are likely to be given low priorities, affects the transaction-confirmation time.
| Citation: |
Table 1. Mean transaction confirmation time for each priority
| Period | Classless [s] | Low priority [s] | High priority [s] | |
| 1st | (2013/10/1-2014/9/30) | 1060.67797 | 1947.47115 | 1044.25043 |
| 2nd | (2014/10/1-2015/9/30) | 1171.98866 | 4887.56496 | 1070.32818 |
| overall | (2013/10/1-2015/9/30) | 1124.13286 | 3888.06977 | 1059.06133 |
Table 2. Comparison of analysis and measurement
| Transaction Type | Arrival Rate | Measurement [s] | Analysis[s] |
| Classless | 0.9709120529 | 1124.13286 | 1112.025339 |
| High Priority | 0.9349109906 | 1059.06133 | 1108.773595 |
| Low Priority | 0.0360010622 | 3888.06977 | 1196.469817 |
Table 3. Coefficients of variation for transaction interarrival time
| Period | 1st 2013/10-2014/09 |
2nd 2014/10-2015/09 |
Overall 2013/10-2015/09 |
| Classless | 3.72401 | 15.32505 | 10.17893 |
Table 4. Coefficients of variation for transaction interarrival time, two-priority classes
| Period | 1st 2013/10-2014/09 |
2nd 2014/10-2015/09 |
Overall 2013/10-2015/09 |
| Low Priority | 1.66569 | 3.90654 | 3.01387 |
| High Priority | 3.70045 | 14.94895 | 9.99103 |
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Comparison of analysis and simulation for basic queueing model
Comparison of analysis and simulation for priority-queueing model
Transaction-confirmation time vs. block size, 1st period (October 2013 to September 2014).
Transaction-confirmation time vs. block size, 2nd period (October 2014 to September 2015).
The mean transaction-arrival rate
Transaction-confirmation time vs. block size, October 2013 to September 2014.
Transaction-confirmation time vs. block size, October 2014 to September 2015.
Transaction-confirmation time vs. block size, October 2013 to September 2014.
Transaction-confirmation time vs. block size, October 2014 to September 2015.
The effects of the block size on the transaction-confirmation time
The effects of the micropayments on the transaction-confirmation time
The effect of the block size on the transaction-confirmation time of high-priority transactions
The effects of the block size on the transaction-confirmation time of low-priority transactions