"M2M" is one of those unfortunate modern initialisms that could stand for any of several distinct concepts!
In practice, "M2M" is now generally used to mean "Machine-to-Machine" communication - particularly in the context of remote monitoring and/or control.
Providing remote monitoring and/or control usually requires some sort of "modem" or module to provide a radio link such as GSM, and some "intelligence" to manage the interaction with the connected machine. Unfortunately the radio modems are usually "dumb" devices, so an additional processor is required between the modem and the machine.
An "Intelligent" modem obviates the need for this additional processor by allowing its functions to be embedded within the modem itself.
The Sierra Wireless (formerly Wavecom) Open-AT environment allows custom software to run within Wavecom's standard GSM modules and modems - thus the modem effectively becomes a CPU with a built-in GSM capability.
When retrofitting M2M capabilities to existing equipment, it is often found that protocols are used which are not suited to radio transmission - particularly with regard to the inherent delays involved. Embedding the protocol within the modem removes this issue.
Antronics Ltd have successfully implemented such an Intelligent M2M application in the Sierra Wireless Fastrack modem; the embedded M2M application allows the modem to:
Further examples can be seen here: http://www.antronics.co.uk/portfolio
Open-AT applications are not only compatible with the Fastrack modem, but also with the complete Sierra Wireless range of modems, modules, and chips: