What does the vulnerable time in case of pure Aloha protocol depend on?

What is the vulnerable time of a pure Aloha network transmits 200 bit frames on a shared channel of 200 kbps?

There is no "vulnerable time" since every node is vulnerable at all times.

If a single node becomes faulty and has to leave the group, then there is a 1/3 chance of failure, but the other 2/3 nodes continue operating. If the entire group of nodes becomes faulty, then only one of them can remain alive and it will likely die within a few seconds of the group's first failure.

The vulnerable time is zero as every node is vulnerable to exactly the same problems.

What does the vulnerable time in case of pure Aloha protocol depend on?

In the case of pure Aloha protocol, there is no concept of sending or receiving times, but rather a fixed time-out interval.

The former is derived from the time-out interval parameter, and the latter is derived from the required time of retransmission. If there is no retransmitted message, the receiver will determine that the message was lost due to transmission error and will perform an error control operation. The error control operation can include a transmission request for a retransmitted message or a retransmission request.

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