Advance in network technology leads to the design of new protocols and services. In order to assure successful communication among those new products, testing and validation activities for conformance and interoperability play an important role in the development and deployment of them. In this lecture, we introduce the PLATONIS platform, a platform for validation and experimentation of new protocols and services. The platform is focused on WAP protocols and services, but it is expected to be general enough to be used for other protocols and services such as those of GPRS, UMTS, and wired networks