Abstract. Use of web services also on mobile devices becomes increasingly relevant. However, realizing such mobile web services based on the standard protocol stack is often inappropriate for resource-restricted mobile devices in dynamic networks. On the other hand, using specialized alternative protocols restricts compatibility with traditional service applications. Thus, existing approaches often do not allow to integrate heterogeneous service instances dynamically, as it is, e.g., required for executing mobile service-based business processes. In order to adequately support such more complex and dynamic applications, this paper presents a lean and flexible system architecture which supports both mobile web service consumers and providers by allowing to integrate multiple protocols depending on their capabilities and to dynamically access suitable service instances at runtime. As a proof of concept, the paper shows an exemplary combination of practically relevant protocols for resource-limited devices based on WSDL, ASN.1 and overlay transport and presents its integration in a prototype scenario for supporting decentralized mobile business processes.