Question

4. Identify the key differences between hard real-time, soft real-time and firm real-time systems. Give at least one example of real time tasks corresponding to these three categories. Identify the timing constraints in your tasks and justify why the tasks should be categorized into the categories you have indicated.

5. What is an Embedded and Real Time System?

6. Enumerate some Embedded Computers that are exists from origin of the Embedded Systems.

Answer 1

ANSWER FOR 4 TH QUESTION :

HARD REAL-TIME SYSTEM :

The hard real-time systems are having a strict deadline to follow, and whenever the system missed that deadline then the system failure will occur.

some of the examples are :

aeroplane working - as the aeroplane consist of the engine and its sensor are made as a hard real-time system, where the system is built by considering the fast response,( real-time ), the task is performed with strict deadlines, the sensor is always working to take accurate results, and also there will be 2 engines ( to cope up with an unpredictable event that may occur )

ROCKET LAUNCHES, SATELLITE MISSIONS: as the launch of some satellite vehicles, rocket etc from earth to space should come with strict deadlines form the mission start to the end, so the engine, sensors and all are made by considering these factors. by moving towards a particular trajectory ( path ) until the satellite touches the final destination

SOFT REAL TIME :

Soft real-time systems will try to reach deadlines but in case if it fails then it will not lead to entire system failure. maybe some part of the system or quality of service to maybe declined but can overcome also.

Examples of soft real-time systems:

audio and video delivery system: if a device which plays songs and videos may lag at some time and later can continue the same performance. ( so can't say the system is a  failure)

telephone communication / mobile communication system: during the call, there may be some issues of start trouble, sound clarity etc, but later it may change also, which don't affect the end to end communication

others like: TV, ONLINE video SYSTEM etc

FIRM REAL TIME :

The firm real-time system will make the operation or computation as INVALID if it comes after the deadline period. And same, Like soft real-time systems it will not, falls into a system failure.  but, missing the deadline will decline the QoS ( quality of service for the system ).

example of firm real-time systems :

money transaction systems - if considering an online payment system, if the transaction time expired or some error occurs before the deadline( processing period ) then all the operations made to account will get revoked or marked as INVALID, and new changes are not made in the system

other examples like ------financial forecasting system, - a system for forecasting future financial outcomes,

and the climate forecasting: for prediction of climate changes over time or days

ANSWER FOR 5TH QUESTION :

ans)

Real-time systems will work with strict time constraints and gives a worst-case time estimate for critical operations.( as specifying an accurate time, and before that the operation gets completed successfully )

The embedded system is a microprocessor-based computer hardware system consists of software( embedded inside) that is designed to perform some specific task. examples like: washing machine, toy cars, remote etc.... all these embedded systems are designed to perform some specific task according to the applications need or requirement.

if there is an embedded component present inside the real system, then it termed as REAL-TIME EMBEDDED SYSTEM