The next generation wireless network will be a heterogeneous networking environment consisting various access networks. Discovering and selecting the optimal access networks has significant impact on the service quality offered to applications. One of the main challenges to access network discovery and selection is the heterogeneity of the coexisting access networks in such networking environments. A key to solving this problem lies in flexible and effective interactions among the heterogeneous networks, the network control plane, and various user equipments. The Service-Oriented Architecture (SOA) is gaining high attention and acceptance in IT industry due to its power for coordinating heterogeneous systems for supporting various application requirements. The SOA offers a promising solution to access network discovery and selection. In this paper, we investigate the application of the SOA in wireless networking environments and propose a service-oriented architecture for access network discovery and selection. We also develop the technologies used in this architecture for supporting real-time dynamic network discovery and selection. The developed architecture and technologies are network-independent; thus are applicable to various networks in heterogeneous wireless networking environments.