Machine-to-Machine (M2M) communication is a fast-growing new business segment for cellular mobile networks. This paper describes the various enhancements to the architecture and the protocols of 3GPP mobile networks to meet the increasing demand for M2M communication and to protect the network against signaling overload. While some of the new mechanisms were designed specifically for M2M devices, many of them will also be used to keep the signaling created by the fast-growing number of smartphones under control.