Fourier-based Study of the Oscillatory Behaviour of the Telecommunications Industry

Abstract

Even though business cycles are not new as a concept, they seem to be reasonably new in the telecommunications industry. In the past (up to very recent years), the behaviour of this particular industry sector had shown a steady growth, as measured by almost any kind of indicators: network and infrastructure deployments, equipment manufacturing, network usage, numbers of subscribers and users, stock prices, etc. However, recent developments have altered this long-standing trend and industry behaviour has shown clear contraction symptoms, which, hopefully, will soon evolve into a new and long growth period.

Worldwide telecom investments have grown steadily (as expected), but year-toyear incremental investments, i.e., the difference of investments (expressed in present value) in years (k) and (k-1), display an oscillatory behaviour. This fact suggests the use of the Discrete Fourier Transform method (DFT) to quantitatively characterise this oscillatory behaviour. This paper analyses these oscillations using the DFT to construct and imagine possible scenarios for the near term future, which are based on recent historical data.