Problem using package acronym

With the package acronym you can't sort the entries. Maybe you can write a small per-script. I recommend the package glossaries which is able to do this:

\documentclass{article}
\usepackage[colorlinks]{hyperref}
\usepackage[acronym,toc,shortcuts]{glossaries}
\makeglossaries
\newacronym{TDMA}{TDMA}{Time Division Multiple Access}
\newacronym{WPAN}{WPAN}{Wireless Personal Area Network}
\newacronym{GSM}{GSM}{Global System for Mobile communication}
\newacronym{FPGA}{FPGA}{Field Programmable Gate Array}
\newacronym{IEEE}{IEEE}{Institute of Electrical and Electronics Engineers}

\begin{document}

\section{Intro}
In the early nineties,\ac{TDMA}, \ac{IEEE} , \ac{GSM}, \ac{WPAN} \ac{FPGA}

\printglossary[type=\acronymtype,style=long]
%\printglossary[type=\acronymtype,style=altlistgroup]%alternative style
\end{document}

Now compile with

(pdf)latex
makeglossaries
(pdf)latex
(pdf)latex

As you said, the acronym documentation doesn't mention "sorting" the acronym list. But a more telling fact is that it also doesn't mention either makeindex or bibtex which presumably would be used to sort a "raw" list of acronyms. Furthermore, in the discussion acronym vs. glossaries at comp.text.tex it is stated that acronyms must be sorted "manually in the input file" when using acronym. Bottom line: If you want automatic acronym sorting, switch to a package like glossaries.