Legenda


Inactive Terminal. Click on the area to active the terminal. Click on an active teminal to disactivate it.	Idle Terminal. In every time slot a new packet arrives with probability p₀.	Transmitting Terminal. Either the transmission of a newly arrived packet or the retransmission of a previously unsuccessful packet.	Transmitting terminal involved in a collision.	Backlogged Terminal. In every time slot, the terminal does a new attempt to transmit the (previously unsuccessful) packet again, with probability p_r. No further new packets arrive as long as the terminal is backlogged.

Control the Animation:

Prob of new packet p₀:
Prob of retransmission p_r:
New settings will only affect the animation after you press "apply"

Exercise 1: Game

Experience how a big collision (involving all terminals) is best resolved, by adaptively controlling the retransmission behavior of the terminals. Pressing "Set up and Start" does the following:

The arrival probability is set to p₀= 0.00.
The arrival probability is set to p_r= 0.00
"Activate all."
"Put in backlog."

Then control p_r yourself to minimize the time till all terminals are idle. After you finish, check the (theoretical) benchmark scores.

Exercise 2: Theory

Make a theoretical analysis of the expected collision resolution time for N terminals, fixed p_r and p₀ = 0. How would you choose p_r if you perfectly knew the number of terminals in backlog? Why is this difficult in practice?


		Make all active terminals idle. Remove any backlog.		Put all active terminals in backlog. Give these a packet to be retransmitted.


Time elapsed:		slots
Check the benchmark scores