Java question

In this assignment, we have the following assumptions: a) Slotted Time: In this assignment, Ethernet is operated in a slotted manner. That is, time is divided into a series of timeslots (i.e. Timeslot 0, Timeslot 1, etc.). b) Frame Transmission: All the stations that have data to send are only permitted to transmit frames at the beginning of a timeslot. In addition, it takes 1 timeslot to transmit a frame successfully. This means that if a station sends out a frame at the beginning of a timeslot, with no collision, the frame is successfully received by the destination station by the end of the timeslot. c) Single Channel: There is only one transmission channel in the network under investigation. d) Collision: When two or more stations send their frames in the same timeslot, there will be a collision because there is only one shared channel in the network. In this scenario, the frames will be damaged; consequently, these frames need to be retransmitted. e) Collision Detection: Collision detection is finished during the same timeslot in which multiple frames are sent out simultaneously. Namely, if two or more stations send their frames at the beginning of a timeslot, all the stations will know that there has been a collision by the end of the timeslot. f) Retransmission Scheduling: In the case of collision, BEB is used to schedule retransmissions. Specifically, after i collisions, a random integer R between 0 and 2i – 1 is generated by each station involved in the collision. Once the random number R is generated, the corresponding station will wait R timeslots and thereafter retransmit its frame. For simplicity, we assume that a station gives up its frame transmission after 5 retransmissions. Namely, if the fifth retransmission leads to a collision, the station will not retransmit its frame any more. g) Random Numbers: In real Ethernet, each station generates its own random numbers when necessary. In this assignment, the random numbers used by the stations are provided via an input file named “Input.txt”. h) Number of Stations: In the network under investigation, there are N stations. Note that, in this assignment, N could be 2, 3, 4, or 5. i) Station Name: When there are N stations in the network, the names of the stations are simply Station1, Station2, …, StationN respectively. j) Network Traffic: For simplicity, we assume that every station in the network has only one frame to send at the beginning of Timeslot 0. With this assumption, there is always a collision during Timeslot 0 because N is at least 2. Once Timeslot 0 is over, the stations in the network will use BEB to reschedule their frame retransmissions. A station will remain inactive (i.e. it will not send a frame any more) after its frame is successfully transmitted. After each unsuccessful frame transmission, a station will use BEB to reschedule a retransmission till five retransmissions have been completed.

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