4.2.1 Types of subtopics and aspectsFigure 1 presents the sub fields of research that have been investigated in the field of LBA with mobile devices to date. Our analysis revealed 10 sub fields of research. These categories were derived from explicit claims in the publications. Again, each publication was assigned exactly to one category (no multiple assignments). We obtained a more detailed view of the applied methodologies by analyzing the identified problem-specific aspects (cf. Figure 1). The set of design-oriented contributions (33 publications) is concerned with the development of algorithms, architectures, or software for delivering advertising messages and operating LBA onmobile devices. Thereby the focus lies mainly in exploring the capabilities of LBA (24 publications). Three design-oriented publications focus on privacy issues, 2 explore location techniques, 2 demonstrate viable business models, one publication considers user acceptance from a design-oriented perspective, and another one makes its contribution to the field of usability.