In this post we are going to learn about the What is Real-Time System and Types of Real-Time System which is very easily explained below. This is very interesting topic. There is trending in Quora also.

What is Real-Time System: Definition of RTS

A computer system which is the response on the time is known as Real-Time System. A system that satisfies bounded response time constraint or risk of system failure.

In real-time computing, the correctness depends on the time at which the results are produced not only depends upon the logical result. A Deadline is the given time after a event when a response time has completed.

Key Terms of Real-Time System

  • The ability of the operating system to provide the necessary level of service in a bound response time
  • It responds to inputs immediately(Real-Time)
  • Here the task is completed within a specified time delay
  • Real-time computing is equivalent to fast computing
  • Necessary signaling between interrupt routines and task code is handled by RTS
  • Real-time systems operate in a static environment
  • Real-time programming includes assembly coding, priority intercept programming, writing device drivers

Example of Real-time system

  • In real life situations like controlling a traffic signal or a nuclear reactor or an Aircraft.
  • Mobile Phones, Digital Camera, Microwave Oven
  • Avionics, Radar Control System, Industrial Process Control
  • Command and Control
  • Multimedia system
  • Electronics Warhead Control System
  • Missile Tracking System

Logical / Temporal Correctness

  • If a system misses its time limit then the resulting action can be canceled, can continue, depending on the system option.
  • Its specification includes logical / temporal correctness

Logical correctness: Indicates that the system should produce the correct output (must be verifiable)

Temporal correctness:  Implies that system must produce output at the correct or right time

CPU Architectures & Structure of a Real-Time System

    • The Component of RTOS is its kernel - Monolithic & Microkernel.


1. Monolithic kernel

What is Real Time System and Types of Real Time System (RTS)

2. Microkernel

Characteristics of the Real-Time System

  • Consistency
  • Failure cost is high
  • Concurrency and Multiprogramming Require
  • Requirements of Reliability and fault-tolerant
  • Salability
  • Predictable behavior
  • Performance
  • Computation - Offline (precomputed) and Online (Dynamically)
  • Priority - Static and Dynamic
  • Scheduling - Preemptive and Non-Preemptive

Now we are going to describe the type of Real-Time System.

Type of Real-Time System

Real-Time system can be characterized as

  1. Hard Real-Time Systems
  2. Soft Real-Time Systems
  3. Firm Real-Time System

1. Soft Real-Time System:

  • This System should meet timings constraints. Response time overrun leads to disastrous damage.
  • Here utility value becomes less/drops with time


  1. Exam hall: Delay by 30 minutes allowed. If you very delay then you will not be allowed to appear in the exam.
  2. Word processors
  3. Airline reservation system
  4. Games
  5. Simulations

What is Real Time System and Types of Real Time System (RTS)-Soft real time system

2. Hard Real-Time System:

  • Deadline overruns are tolerable, but not desired.
  • There is no frightening consequence of missing one or more time limits.
  • If a task does not meet the deadline then the system crashes.
  • A difficult time limit is put on a job because late results produced by the job after the deadline can have disastrous consequences.

Example: Onboard computer of a moving aircraft

    1. Measures velocity, height, position, acceleration, air pressure, etc.
    2. Scheduled time collects data with a sensor within 20 minutes
    3. Compares these data against the stored values


What is Real Time System and Types of Real Time System (RTS)-Hard Real Time System

3. Firm Real-Time System:

  • The system does not fail but throws the results (ignores) in case of failure.
  • The system does not fail but throws the results (ignores) pass the deadline.
  • Every 1/30 second has to come in the frame.
  • Frames will not wait for the destination to arrive but switch to the next frame if the 6th frame does not arrive
  • Hard RTS are not periodic
  • Most periodic hard real-time system companies are RT systems

Example: Video Conferencing

What is Real Time System and Types of Real Time System (RTS)-Firm Real Time System- Real time SystemThere is some important question related to the Real-time system which is very helpful for the people who want to learn about the Real-time system.