Cell phone, smartphone -- what's the difference?

Today's definition from IDC for a converged mobile device, which is IDC's equivalent to smartphone in IDC press releases on phone shipments, reads, "A subset of mobile phones, converged mobile devices feature a high-level operating system that enables the device to run third-party applications in addition to voice telephony. Examples of high-level operating systems include Android, BlackBerry, Linux, Mac OS X, Palm, Symbian, and Windows Mobile. Converged mobile devices share many features with traditional mobile phones, including personal information management, multimedia, games, and office applications, but the presence of a high-level operating system differentiates these devices from all others."

Llamas said the definition of "high-level OS" has three parts. "High level is the linchpin of the definition," Llamas said.

A high-level OS, as IDC defines it, means that the OS has to be able to run third-party applications, not just those written by the OS maker; the applications must be able to run on the phone independent of the wireless network; and the OS must be able to run multiple applications concurrently.

By comparison, Gartner Inc. uses a written definition for both entry-level and feature smartphones, with a similar mention of a more powerful OS as an important distinction. Gartner says an entry-level smartphone must run on an open operating system, while the feature smartphone adds support for one or more functions, such as music, video, gaming, pictures, Internet browsing, mobile TV, navigation and messaging. They usually have "larger displays, more powerful processors, more embedded memory and better battery capacity."

Gartner also says the feature smartphones can have a touch screen or a full Qwerty keyboard, but neither one of those is a requirement.

Both IDC and Gartner analysts agreed that the LG Rumor2 is not a smartphone.

Ken Dulaney, a Gartner analyst, said the Rumor2 is "probably not" a smartphone because it doesn't have a "market recognized" operating system or published APIs.

And Llamas said that while the LG Rumor's operating system is "a well-developed proprietary OS," it still isn't a "high-level" OS in IDC's parlance.

Ryan Reith, also an IDC analyst, said the Rumor2 isn't a smartphone because it doesn't support third-party applications. "There's no real opportunity to get to the core of that Rumor OS and allow consumers to use third-party applications of their choice," Reith said.

Reith noted that another defining characteristic of smartphones is that they are beginning to include an applications processor, a piece of hardware that allows the smartphone to run multiple applications at one time.

Even the device maker, LG Electronics, and the carrier, Sprint Nextel, aren't calling the Rumor2 a smartphone, but their reasons don't follow the same lines as the analysts.