Real Time Systems - Unit Wise Questions

1. What is real system? Explain its various components with a suitable block diagram.

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

1. Describe  how is the polling, priority scheduling and schedulability analysis performed for prioritized access in IEEE 802.5 Token Rings. What are the other factors those should be taken into account?

1. What do you understand by basic priority ceiling protocol? Explain it with the help of suitable example.

1. What is real time system? Explain its various components with a suitable block diagram. Explain the RADAR signals processing with block diagram.

1. List the advantages and disadvantage of priority based scheduling. State the validation problem for  priority based system and explain with example.

1. How real time task are scheduled using Latest Release Time (LRT) algorithms? Explain non-optimality of EDF and LST algorithms.

1. What do you understand by Basic Priority inheritance protocol? Explain it with the help of suitable example.

1. Explain the various components of a real time system with suitable block diagram. State and prove the optimal Earliest-Deadline-First(EDF) algorithm.

2. Differentiate between fixed priority and dynamic priority algorithms.

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

1. Describe the rules for basic priority inheritance protocol with example.

2. Define priority driven algorithms. State and prove the optimal earliest deadline first (EDF) theorem.

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.

2. What do you mean by static computation in fixed-priority systems? Explain with example.

2. Differentiate between fixed priority and dynamic priority algorithms. State and prove the optimality of Least Slack Time(LST) First algorithm.

2. Define resource reservation protocol. Explain in brief, the different types of issues that a resource reservation protocol must deal with.

3. Differentiate between rate-monotonic and deadline monotonic algorithms with example.

2. Differentiate between rate-monotonic and deadline monotonic algorithms with example.

2. What do you understand by digital control? Prove that Earliest Deadline First (EDF) algorithm is not optimal for scheduling preemptable jobs on more than one processor.

2. What is slack stealer server? How it is different from polling server? Show that slack stealer improves the response time of a periodic jobs in deadline driven system.

2. Compare and contrast between fixed and dynamic priority system."The implementation of slack stealing server for fixed priority system is difficult." Is it true? Explain.

2. Explain the multiprocessor priority ceiling protocol with suitable example.

3. What is multi processor priority ceiling protocol? Describe it with the help of suitable diagrams.

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

3. Explain  the Stack Stealing in deadline-driven system with suitable example.

3. List the properties of basic priority inheritance protocol. "The priority ceiling protocol avoids both priority inversion and deadlock in resource allocation." Justify it with suitable example.

3. What is mutual exclusion and critical section? List and explain the effects of resource allocation in real time scheduling with example.

3. What are the three commonly used approaches to scheduling the real time systems? Compare each of them.

3. Explain the Greedy Weighted Round Robin(WWR) disciplines and time. Driven Weighted Round (WWR) disciplines with example.

3. What do you understand by slack stealing in a deadline driven system? Explain the operation of a slack stealer with example.

3. Define rate-monotonic (RM) and deadline-monotonic (DM) algorithms. Describe the DM algorithm with example.

4. Differentiate between dynamic and static real time systems.

4. Differentiate between fixed priority and dynamic priority algorithms.

4. What do you understand by "Tracking" and "Gating" in a Radar system? Explain.

4. Explain how real-time commands are handled in Air Traffic Control (ATC) System.

5. What is the use of priority ceiling protocol?

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

4. Define schedule and scheduler. List out the conditions under which a schedule becomes a "valid  schedule".

4. Define wormhole network. Describe routing and transmission mechanism in a wormhole network.

4. What is the difference between real time system and embedded system? Explain the sample data system with necessary block diagram.

4. Explain the Kalman filter with example.

4. Differentiate between dynamic and static real time systems.

4. Explain the real-time command and control system with suitable example.

4. What is digital control? Explain with example.

5. Draw and describe a model of real time system.

5. Explain the digital controller with example.

5. Describe the term tracking and gating used in a radar signal processing system.

6. Highlight on internet and resource reservation protocols.

6. Explain the different issues that needs to be dealt by a resource reservation protocol within a multicast environment.

6. Explain the diagram of radar signal processing and tracking system.

6. Differentiate between offline and online scheduling in a real time system.

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

6. What are the advantages and disadvantages of clock driven scheduling approach?

6. Compare and Contrast between Sporadic and Aperiodic job. At what condition the scheduling algorithms becomes optimal? Explain.

6. Differentiate between dynamic system and static systems with example.

7. Highlight on resource parameters of jobs. Why is it critical?

6. What is the major difference between precedence and task graph? Explain about the functional parameter of real-time jobs.

6. Differentiate between data dependency and temporal dependency.

6. Define release time jitter, relative deadline, and hyper period. If the execution times of three periodic tasks are 1, 1 and 3, and their periods are 3, 4, and 10, then find out the total number of jobs in the hyper-period, and total utilization of jobs.

8. Highlight on the requirements of Real-time Multimedia Traffic.

7. Describe the significance of laxity type with the help of suitable diagram. 

7. State and prove the Optimal Least-Stack-time-first (LST) algorithm.

7. Differentiate between clock-driven scheduling and priority-driven scheduling.

7. Describe the operation of total bandwidth server in brief.

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

7. Explain the sporadic server in fixed priority system.

7. How sporadic jobs are scheduled in EDF scheduling? Explain with example.

7. How frame overruns are handled in cyclic Scheduling? Calculate the possible valid frame size for system with tasks T1(2, 1, 3),T2(4 , 1, 6), T3(6, 2, 8) and T4(6, 2, 8).

7. Define temporal parameter of real time workload? Explain different types of temporal parameters of a job.

7. List out the advantages and disadvantages of a clock driven approach to scheduling.

8. Define the clock-driven scheduling. What are the advantages and disadvantages of it?

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

8. Differentiate between online and off-line scheduling.

8. List the assumptions made for priority driven scheduling. Construct the LST schedule for a system with tasks T1(2,0.5), T2(3,1) and T3(6,2).

8. Explain the meaning of "priority-invention" with the help of timing diagram.

8. Differentiate between dynamic systems and static system in real time systems.

8. Explain the slack computation in fixed priority system with example.

9. Explain Priority-Inversion with the help of timing diagram.

8. State the optimality conditions for fixed priority algorithms. Consider a system with real time tasks T1(4, 1, 6) T2(10, 2, 20)  T3(20, 1. 30), T4(10, 5, 8) and T5(8, 1) are scheduled by using EDF algorithms. Find it feasible to schedule or not.

8. Explain the schedulability of sporadic jobs in deadline-driven systems.

8. What are the requirements for Real-Time Multimedia Traffic? Explain. 

9. Differentiate between fixed-priority algorithm and dynamic-priority algorithm.

10.What do you mean by scheduling hierarchy? Explain.

9. Why does the scheduler perform an acceptance test while scheduling sporadic jobs? Explain.

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

9. What do you understand Greedy Weighted Round Robin scheduling in a packet switched network? Explain it in detail.

9. What are the procedures of a simple acceptance test in deadline-driven systems? Explain.

9. Explain  with diagram of real time communication model.

9. State the optimality conditions for dynamic priority algorithms. Consider a system with real-time T1(4,1,6), T2(10,2,20), T3(20,1,30), T4(10,0,5.8) and T5(8,1)are scheduled by using RM or DM algorithms. Find is it feasible to schedule or not.

9. Differentiate between priority inheritance and priority ceiling protocols.

9. What do you understand by 'Busy Intervals' in fixed priority tasks with arbitrary response times? Explain.

9. Differentiate between periodic and bandwidth preserving server. Explain deferrable server with example.

10. What are the properties of the priority-inheritance protocol? Explain.

10. What are the different types of issues that a resource reservation protocol must deal with in a multicast environment? Explain. 

11. Explain medium-access protocols of broascast networks.

10. Prove that the longest blocking time suffered by every job is the same for the sack based and basic priority ceiling protocols?

10. Define busy interval. Calculate the busy interval for task T1(2,1), T2(3,1,25) and T3(5, 0.25) over the interval (0, 12) schedule through the Rate Monotonic (RM) algorithms.

11. Example digital control with example.

10. Explain the sporadic server in fixed-priority systems with example.

10. Describe a simple bin parking formulation method of task assignment in a multiprocessor system.

10. Define Deferrable server.State and explain the consumption and replenishment rules of deferrable servers. 

10. What is constant utilization server algorithm ? Explain.

11. Explain the weighted round robin service disciplines with example.

11. How is the connection established in a Greedy  WRR scheduling algorithms ? Explain.

11. Define task assignment in end to end task model. State and explain the task assignment in multiprocessor system using simple bin packing algorithms with example.

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

11. Explain 'Priority Inversion' caused by resource contention, with suitable example.

11. What is RCTP control protocol? Explain with example.

11. What is rate monotonic algorithm? Explain with suitable example.

12. Explain clock driven approach. What are its disadvantages?

10. Define critical instant. Calculate the critical instant for real-time tasks: T1(2,0,6), T2(2,5,0.5), T3(3,1.2) schedule through the Deadline Monotonic (DM) algorithms over the interval(0, 12).

11. What do you understand by Task Assignment, Job Shops and Flow Shops? Explain.

11. Describe the meaning of resource conflict, blocking, priority inversion, and deadlock caused by resource contention.

12. Explain the real time communication model with diagram.

12. Define real time traffic model.List and explain the different types of services discipline used in real time communication.

12. Write down the total bandwidth server algorithm and explain it.

12. Describe the meaning of job shops and flow shops of end to end tasks in a multiprocessor scheduling.

12. Explain the priority based service disciplines for switched networks.

12. Describe a real time communication architecture of distributed system with diagram.

11. Explain about Multiprocessor Ceiling Protocol (MPCP) for resource allocation in a multiprocessor system with example.

12. Why real time data cannot use TCP protocol? Give reasons.

12. Describe a real-time communication model with the help of suitable diagram.

13. Write Short notes.(any two)

a. Kalman filter

b. Deadbeat control

c. Sporadic jobs

13. Write short notes (any two)

a. Priority inheritance

b. Critical instants

c. Soft real time system

13. Write short notes on:(Any Two)

a. Service discipline in real time communication

b. Critical section and outermost critical section

c. Context switches

12. Define the terms throughput, Delay and jitter. How medium access protocol used in control area network(CAN)? Explain.

13. Write short notes on(any two):

a) Data dependency and functional parameter of job.

b) Resource Reservation Protocol

c) Pros and corns of cyclic scheduler

13. Write short notes on:

a. Embedded System

b. Real Time Control Protocol(RTCP)

13. Write short notes on:

a. Fixed Priority Scheduling in CAN

b. Greedy WRR discipline

13. Write short note on:

a. Real time protocol

b. IEEE 802 token ring

13. Write short notes on:

a) Identical versus heterogeneous processors

b) Real Time Protocol(RTP)

13. Write short note on:

a. Scheduling hierarchy 

b. Communication in multicomputer system.

13. Write short notes on(any two):

a) Inter-Processor Communication(IPC)

b) Weighted Fair Queuing Server

c) Offline Vs. Online Scheduling

1. Explain the hard real time system and soft real time system  with example. 

5. Why validation of hard timing constraint is required? Explain the characteristics of soft real time system.

5.  What are the meanings of hard real time system, hard timing constraints and temporal quality of  service guarantees?

5. What is hard real time system? Explain with example.

5. What do you understand  by timing constraints and tardiness? Why does a hard real time system require time guarantees?

5. What is timing constraints? Explain the characteristics of Hard Real-Time system with example.

5. What is soft real time systems? Explain with example.

6. Differentiate between hard real time systems and soft real time systems. Give three examples of each.