Service-orientation is not only a means for systems integration, but also an architecture paradigm for building systems. Flexibility, adaptability and interoperability are some of the benefits derived from the adoption of SOA. These principles are often applied to build distributed systems. But whether SOA is applied or not, building a distributed system is still complex, what increases the demand on high-quality middleware to achieve success. This paper presents a runtime service integration architecture that enables distributed service interactions regardless the capabilities of the devices involved, i.e. to deal with services distribution over a heterogeneous network. The solution presented is built upon the OSGi service platform which has been leveraged with OSS middleware components to provide remote communications (with connectors and adaptors), service discovery, service binding and service publication. The development of this architecture is carried out within the ITEA OSIRIS Consortium and is being applied to industrial case studies; including a tax administration applications, service provisioning to residential environments and a mobile CRM.