Could your computer be turned into a utility that you pay for based on how powerful it is and how often you use it? The world's largest software company thinks so.

The U.S. Patent and Trademark Office last week published a Microsoft patent application that signaled the software giant's interest in developing a metered pay-as-you-go computing system in which consumers would pay a monthly fee to use their PCs but little or nothing up front to buy them.

Although the patent office rejected Microsoft's application, reports tech news Web site Ars Technica, the company laid out a plan for the future of computing, where bits and bytes are delivered to one's home similar to the way utility companies deliver electricity. Based upon documents available on the patent office's Web site, Microsoft's application lacked sufficient detail in several areas, including descriptions of the service and how it is different from other ideas already issued patents, according to patent examiner Murali Dega. Microsoft has the ability to tweak its application and resubmit. When contacted, the company would not disclose its plans regarding the patent application or the proposed metering service.

Here's how it might have worked, according to the patent application: Microsoft would bundle the PC hardware and software into three services—"Office," "Gaming," and "Browsing." The Office bundle would include word processing and spreadsheet applications along with a PC containing a standard graphics card and processor (price tag: $1 per hour). The Gaming bundle, however, might include no productivity applications but deliver a PC with 3D graphics support and a lightning-fast processor (price tag: $1.25 per hour). The Browsing bundle might include no productivity applications, medium graphics performance and high speed network interface (price tag: 80 cents per hour). The patent application does not make clear whether the individual PCs used would have differing hardware components (processors and graphics cards, for example) or have identical components that are switched on or off as needed. One hopes that these prices are simply examples. Given how many hours PCs are typically used in a home or office setting, the pay-as-you-go model would quickly add up to much more than the cost of buying a PC and its software.

It's the classic case of buying v. leasing. The upside: a consumer would be able to choose the computer's performance level (and change it as desired) while keeping up with the latest software (including operating systems, databases and Web browsers) without having to buy the actual box (computers, like cars, are notorious for losing their re-sale value the minute they are switched on the first time). The downside: users might end up paying more for, in essence, renting equipment than they would if they bought and owned everything, although Microsoft poses its projected costs simply as estimates. There might have even been a one-time charge for equipment leasing.

This wouldn't be a return to the day of so-called "dumb terminals" with no local memory connecting into mainframes, nor would this follow the "network PC" model (an unsuccessful concept Microsoft got behind in 2001). The metered PCs that Microsoft pitched to the patent office would have had encrypted local memory that stored the performance specifications for each component. Network PCs, as proposed, would have had very little local memory and been tightly controlled, for example, by your company's IT department (read: no playing solitaire on company time).

Regardless of whether Microsoft re-files the patent, for such a plan to work more detail needs to be provided regarding how the metering technology would function. Microsoft proposed possibly measuring elapsed time that the computer is on, active time during which the computer is used or the amount of time a given software application is used. "In one embodiment, the billed value is accumulated according to both usage time and a composite of performance characteristics for scalable components," according to the patent application. The company proposes that billing be done through a pre-paid account or at regular intervals (such as monthly).

©; Brent Wong