Handsets are first and most about voice, about communications. The ITU has
published Voice Revenues in the Telecommunications which is worth checking out:
“In 2004, as in 1991, voice constituted more than 90% of telecom revenue surpassing, by far, income from any other source. In the coming years, voice is expected to stay strong driven by falling prices and increasing volumes of traffic.”
Also download the presentation
The Future of Voice: Framing the debate by Tim Kelly and Jaroslaw Ponder
ceo