should be taken for n × 6 times. If there are m flows, the calculation should be taken for m × n × 6 times. It will take n × 6 × (m − 1) times to calculate the elements in contention matrix. Therefore, (2m − 1) × n × 6 times of calculation are needed in total. The time complexity of the whole contention matrix is O (n), as m is small and can be ignored.