The elements under test will be regarded as black boxes with well-defined external interfaces. Primarily, the correct behavior of an element at its external interface will be tested.
The tests are typically performed between vendor test laboratories using co-located equipment only if necessary.
By necessity real network elements, mobile stations and applications are used. Conformance, mobile station, application, performance and stress testing is outside the bounds of IOT. In fact conformance testing and the necessary integration of mobile stations and applications used during testing is seen as internal testing and as such is a pre-requisite to IOT. The mobile stations, applications and other necessary network elements used during testing are only seen as tools to verify the interface under test.
In addition, integration and acceptance testing are not seen as part of IOT, as these are seen as operator network specific activities where the system is optimized to give the best performance.