The present document addresses integrated location systems 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. The requirements herein are intended to address the growing use of complex location systems needed for the provision of location-based applications particularly for the mass-market (refer to [i.1]). The present document defines the functional requirements applicable to location systems@ based on a synthesis of types of applications relying on location-related data provided by location system. The present document can be considered as the Stage 1 characterization of location systems according to the ITU/3GPP approach [i.2].