The remainder of this paper is organized as follows. Section 2 discusses related work. In Section 3 we discuss the composition of a wireless NIC and present opportunities for distinguishing between different types of NICs. Section 4 presents the rational for using signal processing and introduces our technique. We also discuss how to represent a wireless traffic stream as a signal and how to compare spectral content in Section 4. In Section 5, we use our technique to identify NICs during active scanning. Section 6 concludes the paper and discusses future work.