ON THE ABILITY OF ESTABLISHING REAL-TIME CHANNELS IN POINT-TO-POINT PACKET-SWITCHED NETWORKS

There are numerous applications which require packets to be delivered within pre-specified delay bounds in point-to-point packet-switched ne tworks. To meet this requirement, we define a real-time channel as a u nidirectional connection between two nodes in such a network that guar antees every packet to be delivered before a user-defined, end-to-end deadline. The goal of this paper is to lay a mathematical basis for th e problem of establishing real-time channels by (i) deriving a necessa ry and sufficient condition for the schedulability of a set of channel s over a link, and (ii) developing an efficient method for calculating the minimum delay bound over a link for each channel. Given the traff ic characteristics of a channel, our results can be used to check whet her or not every packet will be delivered within a pre-specified delay bound. The results are also applicable to a wide variety of real-time task scheduling problems.