1.1 Purpose of the document This document is the CEN Technical Report WP2-D2 of the GP-START project, regarding the test procedures for assessment of robustness to security attacks. Starting from the definition of security attacks taxonomy and security metrics highlighted in FprCEN/TR 17464:2019, this task aims to: 1. Specify test facilities to be used in the field tests. This comprises both hardware and software equipment. 2. Define relevant test scenarios applicable to security performances. Also, the field test needed for validation of scenarios will be properly described. 3. Define end-to-end test procedures comprising experimental validation of the whole test chain. The results will serve as the operational basis for field testing of robustness against security attacks. 1.2 Overview of the document The outline of the document is as follows: " Clause 5 provides a review of security metrics, in line with the other deliverables of the project and in particular with FprCEN/TR 17465:2019 and FprCEN/TR 17464:2019. " Clause 6 consolidates the test approach with respect to jamming and spoofing oriented scenarios. " Clause 7 provides a definition of relevant test scenarios, applicable to security testing, starting from outcomes of FprCEN/TR 17464:2019. " Clause 8 provides an in-depth discussion regarding test facilities, focusing on both data recording and replay. " Clause 9 concludes with a set of real-life tests, for a preliminary end-to-end validation of the procedures.