We are developing GENESIS, a new seamless total environment for designing, developing, installing, and operating various types of telecommunication networks as extremely large distributed processing applications in the future network integrated by ATM. Similar uniform architectures for quick introduction and easy management of service or operation applications have been proposed, such as by TINA, but there has been insufficient study on how to operate and con figure those applications. This paper discusses the implementation model and execution environment in GENESIS from the viewpoint of flexible operation according to network conditions. The implementation model can describe detailed configurations under various conditions on design or operation, independently of the execution environment. To achieve the goals of GENESIS, our execution environment provides message handling functions and a transparent interface for controlling network resources independently of the configuration, and dynamic reconfiguration functions that are independent of the execution. This paper also reports the prototype system GENESIS-1. The GENESIS-1 message handling mechanism and the effect of the reconfiguration functions are described.

In recent years, communication networks have been required to introduce various services and efficient operation of network resources. There have been many discussions about hierarchical abstraction models of network functions and a distributed application platform, such as studies of the intelligent Network conceptual model and Distributed Application Framework in CCITT. On the other hand, communication networks (telecom networks, packet switching networks, common channel signaling networks and intelligent networks) will be integrated in Asynchronous Transfer Mode (ATM) nodes in the future B-ISDN era. Each communication network will be constructed on an integrated transport network. This paper proposes the new concept of "Software Defined Architecture (SDA) ", a conceptual model for implementing communication networks and a network system model for describing communication networks. This concept makes possible communication networks that can be quickly constructed in an integrated transport network and dynamically reconstructed in response to traffic fluctuations and node overloads. Using the network system model, a network system is specified by three kinds of specifications: component, frame and implementation. The network system is constructed or reconstructed on the basis of these specifications. This paper reports an intelligent network system as an example of a communication network which applies the SDA concept.