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Te-Kai Liu et al.: General Performance Model for Mobile Slotted ALOHA Networks

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Fig. 1. The topology of a K-group slotted ALOHA system. All groups use the same transmission power. But due to the near-far effect, the received power at the central station is different.

Fig. 2. Throughput for a 5-group system with s = 0.02, q = 0.1, d = 1.0, and R = 4. Note that as g decreases, throughput increases.

Fig. 3. Throughput for a 5-group system with s = 0.02, q = 0.1, g = 0.125, and d = 1.0. Note that as R decreases throughput increases.

Fig. 4. Throughput for a 5-group system with different fading parameters (d). In the cases where the near-far effect is not significant (e.g., g = 0.5, R = 10 in the example), throughput increases as d increases. (For other parameters, s = 0.02 and q = 0.1 for all groups.)

Fig. 5. In the cases where the near-far effect is significant (e.g., g = 0.125 and R = 4 in the example), throughput decreases as d increases. (s = 0.03 and q = 0.1 for all groups.)

Fig. 6. Unbalanced throughput for a 5-group system with q = 0.1, g = 0.25, d = 1.0, and R = 4 for all groups.

Fig. 7. Balanced throughput for a 5-group system with different retransmission probabilities for each group. Specifically, g = 0.25, d = 1.0, and R = 4 for all groups; q1 = 0.03, q2 = 0.055, q3 = 0.1, q4 = 0.16, and q5 = 0.2 for group 1 through group 5, respectively.