  Aided by the ubiquitous wireless connectivity, declining communication costs,
and the emergence of cloud platforms, the deployment of Internet of Things
(IoT) devices and services is accelerating. Most major mobile network operators
view machine-to-machine (M2M) communication networks for supporting IoT as a
significant source of new revenue. In this paper, we motivate the need for
wide-area M2M wireless networks, especially for short data packet communication
to support a very large number of IoT devices. We first present a brief
overview of current and emerging technologies for supporting wide area M2M, and
then using communication theory principles, discuss the fundamental challenges
and potential solutions for these networks, highlighting tradeoffs and
strategies for random and scheduled access. We conclude with recommendations
for how future 5G networks should be designed for efficient wide-area M2M
communications.
