This optional element specifies the conditions and methods of sampling, as well as the method for the preservation of the sample(s). This element may appear at the beginning of test methods.
This optional element gives all the instructions concerning the procedure for determining the values of characteristics, or for checking conformity to stated requirements, and for ensuring the reproducibility of the results. If appropriate, tests shall be identified to indicate whether they are type tests, routine tests, sampling tests and so on.
Instructions relating to test methods may be subdivided in the following order (where appropriate):
preparation and preservation of test samples and test pieces;
Test methods may be presented as separate clauses, or be incorporated in requirements, or be presented as annexes (see clause 6.3.8
) or as separate parts (see clause 5.2.1
). A test method shall be prepared as a separate 3GPP TS if it is likely to be referred to in a number of other 3GPP TSs.
The need for specification of test methods shall be evaluated on a case by case basis.
A test specification enables verification that products designed to a standard conform to its requirements. When writing a 3GPP TS you should consider the need for an accompanying test specification.
Every requirement of a 3GPP TS specifying a product (equipment, system or service) needs to be testable, and such requirements need to be clearly distinguishable from statements of fact or of supposition.
Comparing the two sentences below:
"On receiving a START CALL message, the terminal shall respond by sending an ACKNOWLEDGE message within a delay of t1."
"On receiving a START CALL primitive, the layer 3 protocol of the terminal shall move to state CALL ACTIVATED and shall start timer t2."
It is clear that conformance to the first requirement can be verified by external stimulus and observation, whereas the second puts demands on a conceptual model which cannot be explicitly tested. Whilst requirements of the latter sort are useful – even essential – for describing operational details, the essential behavioural characteristics (normative provisions) are given by requirements of the type of the former, and only these are verifiable.