Last year I became interested in working with M2M (machine to machine) systems. M2M is the simple idea of two computers communicating directly with each other without a human in the loop.
As an example of M2M, consider a so-called smart utility meter that is able both to transmit load information in real time to a server at the power company, and to receive command and control instructions in return from the server. (The actual communications could take place over a cellular network, a powerline network, or perhaps even over the Internet using a telephony or broadband connection.) An excerpt from that Wikipedia article demonstrates the types of new functionality that are enabled through real-time bidirectional communications with utility meters: The system [an Italian smart meter deployment] provides a wide range of advanced features, including the ability to remotely turn power on or off to a customer, read usage information from a meter, detect a service outage, change the maximum amount of electricity that a customer may demand at any time, detect unauthorized use of electricity and remotely shut it off, and remotely change the meter’s billing plan from credit to prepay, as well as from flat-rate to multi-tariff .