So What's an 'Embedded System,' Anyway?

As predictions for the size of the embedded market explode, one begins to wonder if the term is becoming so all-encompassing that it's starting to lose its meaning.

Of course, we don't have such difficulties at our own Embedded Systems Conference, which will take place in Boston next week. (Visit here to look at the program and register.)

I'm referring more to the recent International Data Corp. prediction that 1.8 billion embedded systems will be shipped in 2011. This would account for $1 trillion of revenue at the component and software level. IDC predicts that both figures will at least double by 2015, yielding more than 4 billion systems shipped and $2 trillion in revenue. Such systems will require 14.5 billion microprocessor cores by the end of 2015.

That's all well and good, except for the fact that IDC calls this realm "intelligent systems" and includes in it anything with a networked microprocessor. With such a definition, it's hard to figure out where IT leaves off and non-client/server systems begin, or what might fail to meet IDC's definition of an intelligent system.

It seems likely that a self-contained network, like an automotive infotainment system, could fall within this field. As healthcare automation grows from standalone MRI and patient-monitor machines to newer real-time networks spanning the hospital or clinic, it might be hard to separate the embedded network from the IT backbone. And what about a body-area network in the wearable and implantable electronics of the coming decade?

This is a non-trivial issue in deciding how such systems should be counted as traditional embedded markets mature. Factory floors, for example, have featured islands of automation for decades, with programmable logic controllers linked via CAN or FieldBus. As every system with an IP address becomes linked on the factory floor over the next few years, does it all fall under that magical "embedded" or "intelligent" rubric?

What about a workstation that manages robotic arms but also links with enterprise back-office networks? Is that an embedded system or an IT system? If it's embedded, does that make the server or mainframe collating the real-time factory floor data a part of the embedded network, as well?

I'm making the assumption here that the factory floor is already very close to standardizing on Ethernet (in both wired and WiFi versions) at Layer 1 and 2, and IP at Layer 3, with a mix of TCP and UDP protocols for transport. Sure, clusters of ZigBee and FieldBus and CAN will be prevalent everywhere, but Ethernet/IP will be the lingua franca uniting all.