Answer all questions and all parts please

Conceptual Questions: [10 points per question] 1- What is the main difference between the collision-avoidance and collision-detection CSMA methods? 2- Can we use a standard reservation based method, in a system with dynamic number of users? Why? 3- What is the difference between half duplex and full duplex transmission method? 4 Explain token passing method using sequential ordering. True/False Statements [No justification is required] [5 points per question] 5- In slotted Aloha system, a user sends a packet AS SOON AS it is generated (T/F) 6- In a token passing method, a user who takes turn and has no information to send, holds the token until collecting some information to send (T/F). Token passing method is an appropriate access method for Ad-hoc sensor networks without a central controller (T/F). In reservation based method with n users, there are exactly n transmit intervals between two consecutive reservation intervals (T/F). 7- 8- Problems 9- Consider a wireless communication system with timing advance of 30us. What is the maximum acceptable 10-In a wireless system with Aloha access method, the transmission interval is T = 20ms and the probability distance of a user from the base station? Why? [10 pts of a user to generate a packet in time [t, t + T] is P.-2%. Calculate the following quantities in a system with n 5 users 140 points a) Probability of success for user #1 [5 pts] b) Probability of success for a user: pluser#1 success)+-p(user#5 success) [5 pts] c) What is the optimal pe that maximizes the success probability? [5 pts] d) What is the exact success probability in this case? 15 pts] Repeat parts (a) to (d) for slotted Aloha system (20 points). 11- Consider a system with CSMA-CD, where we use slotted Aloha (with optimal transmission probability) in the contention period. If a contention time slot is 10 pas and a transmission time slot is 1ms, what is the channel utilization rate? [20 points] 12- Consider a system with CSMA-CD, where we use slotted Aloha (with optimal transmission probability) in the contention period. The users are distributed in a circle around the base station with radius of 5 km. Contention time slot is set to the minimum acceptable value based on timing advance. The transmission time slot is set to 1ms. What is the channel utilization rate? [20 points 13- Consider a TDMA system with two users. If the total bitrate is 30kbps and the input traffic for user 1 and user 2 is respectively 12 kbps and 24kbps, calculate the total throughput of the system as well as the fairness metric (in terms of Jain index and the entropy) for the following systems. [30 points] a) Using 1 timeslot for user#1 and 1 timeslot for user#2 in a 2TS TDMA system User#1 User#2 User#1 User#2 b) Using 1 timeslot for user#1 and 2 consecutive timeslots for user#2 in a 3TS TDMA system User#1 Userez userg2 User#1 Usem user82