Just the fax—differentiating voice and fax phone lines using call billing data
Haim Y. Kaplan, Martin J. Strauss, Márió Szegedy · 1999
this paper we are particularly concerned with classifying lines as either voice or fax, we point out that the techniques we use may apply in other classification problems as well. The ability to classify lines helps a telecom company to predict revenue and infrastructure needs, to formulate new service offerings, and to detect fraud. For more discussion on analysis of call data (especially in connection with detecting fraud), see [CEWB97].