One of the most active areas in the research and practice of object-oriented systems development is in the identification and reification of design patterns. A design pattern is a generalized solution to a commonly-recurring problem. Although many refrences are available on the topic, little information is available for design patterns specific to the real-time embedded systems world. Real-time systems benefit as much as standard desktop systems, but many of the patterns are subtly different in their application. This paper discusses architectural design patterns. Many different are presented along with the requirements for their effective application.