Reduction of useless services with timing constraints

A distributed computing system consists of objects and messages which are transmitted between objects. An object can request other objects to do some services by passing messages through a communication system. Usually, the services are done if the message transmission on the communication system is reliable. However, in some applications with timing constraints, a service may be of no value if it violates some constraints. The authors thus can allow the object to send the constraint within the message to avoid this useless service. In validating the satisfaction of a service for a constraint, using the current elapsed time and using the predicted elapsed time are discussed. The relative accuracy of the prediction in several types of message transmissions is also explained.<>