We introduce a novel framework that provides a logical structure for classifying and organizing fundamental components and concepts of location privacy. Our framework models mobile networks and applications, threats, location-privacy preserving mechanisms, and metrics. We demonstrate the relevance of our framework by showing how the existing proposals in the field of location privacy are embodied appropriately in the framework. Our framework provides "the big picture" of research on location privacy and hence aims at paving the way for future research. It helps researchers to better understand this field of research, identify open problems, appropriately design new schemes, and position their work with respect to other efforts. The terminology proposed in this framework also facilitates establishing an inter-disciplinary research community on location privacy.