Designing real-time systems are a challenging task. Most of the challenge comes from the fact that real-time systems have to interact with real world entities. These interactions can get fairly complex. A typical real-time system might be interacting with thousands of such entities at the same time. For example, a telephone switching system routinely handles calls from tens of thousands of subscriber. The system has to connect each call differently. Also, the exact sequence of events in the call might vary a lot. In the following sections we will be discussing these issues...

• Real-time response

• Recovering from failures

• Working with distributed architectures

• Asynchronous communication