Device-to-device (D2D) proximity discovery enables spectral reuse via D2D communications as well as a range of innovative proximity services, such as enhanced social networking and location services. To develop a scalable discovery mechanism, signals transmitted by geographically disparate devices should not differ drastically in their received power at each monitoring device. Discovery schemes are proposed to deal with this near-far issue. Analysis and simulation results are provided to characterize the performance of discovery schemes.