Real Time Systems 2078

Group A

Attempt any two questions:(2*12=24)

1. Define deferrable server.Describe the operation of deferrable server in detail with example.

2. What are three commonly used approaches in scheduling the real time systems? Compare and contrast each of them.

3. A system contains nine non preemptable jobs named J_i, for i = 1,2,...9. The execution times are 4, 3, 3, 3, 5, 5, 5, 5, and 10, respectively, their release times are equal to 0, and their deadlines are 10.J1 is the immediate predecessor of J₉, and J₄ is the immediate predecessor of J₅, J₆, J₇, and J₈. There are no other precedence constraints. For all the jobs, J₁ has a higher priority than J_k if i < k.

a) Draw the precedence graph of the jobs.

b) Can the jobs meet their deadlines if they are scheduled  on three processors?

c) Can the jobs meet their dead lines if made preemptable and schedule them preemptively.

Group B

Attempt any eight question.(8*7=56)

4. Differentiate between dynamic and static real time systems.

5. Briefly explain clock driven scheduling. List its pros and cons.

6. Highlight on internet and resource reservation protocols.

7. Where and how can we use off-line scheduling and on-line scheduling ? Explain with an example.

8. What are the challenges in validating timing constraints in priority-driven systems? Explain.

9. Compare and contrast on slack stealing in fixed-priority systems and in deadline-driven systems respectively.

10. How can concurrent access to data objects be controlled and why is it required?

11. Explain medium-access protocols of broascast networks.

12. How precedence constraints and data dependency effect the execution time of RTS ? 

13. Write Short notes.(any two)

a. Kalman filter

b. Deadbeat control

c. Sporadic jobs