This multi-part deliverable addresses integrated GNSS based location systems (GBLS) that combine Global Navigation Satellite Systems (GNSS)@ with other navigation technologies@ as well as with telecommunication networks in order to deliver location-based services to users. As a consequence the present document is not applicable to GNSS only receivers. This multi-part deliverable proposes a list of functional and performance requirements and related test procedures. For each performance requirement@ different classes are defined allowing the benchmark of different GNSS Based Location Systems (GBLS) addressing the same applications. The requirements herein are intended to address the growing use of complex location systems required for the provision of location-based applications particularly for the mass-market (refer to ETSI TR 103 183 [i.1]). The present document defines the functional requirements applicable to location systems@ based on a summary of types of applications relying on location-related data provided by location systems. The present document can be considered as the Stage 1 characterization of location systems according to the ITU/3GPP approach [i.2].