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glad i found this site. would appreciate help with this: in picture i uploaded there's a state diagram of a "stop and wait" protocol in a half duplex channel. we assume current status is (10A).

problem i have is that:

1) can we know the next thing that is going to happen base on the diagram? if not, what is the missing detail?

2)if the current position was (00-), could we know what is going to happen base on the diagram? if not, what is the missing detail?

so here what i think:

protocol stop and wait using a half duplex scheme provides a two directional transmission of data from sender to receiver and vice versa, but only one direction at a time, which can create a troublesome and unreliable enviroment in case of collision, meaning both stations stop transmitting and wait some intervals before transmitting again. because of this, when implementing the protocol there's a need to prevent collisions.

because of this:

1)i think that we can not know in advance what would be the next state, because we don't know ahead if there was a collision. we can not know if it continues to 000 as intended, or to 10- because of a collision.

2)if the current state is 00-, it means that there was an error, probably collision, which means that it is now recovering from it by dropping the frame and resetting the number of the frame in the channel to 0 again.

enter image description here

thank you for helping me

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