P_gand P_R determine channel and cluster dwell time. (A and B) Surface plots showing the relationships between P_g, P_R, and channel dwell time (A) or cluster dwell time (B). (C and D) Frequency distributions of channel and cluster dwell times with P_R equal to 0.0001 (C) or 0.001 (D). For the simulations in C and D, P_g and P_n were 0.01 and 0.00006, respectively.