Overview

The big question for cellular handset designers today is how to simplify. A host of DSPs, CPUs and application-specific hardware accelerators are being crammed into tomorrow's cell phone to handle an exploding applications load.

That's because, as the contributed articles in this section note, tomorrow's phone is expected to be a digital camera, MP3 audio player, Gameboy and PDA that can browse the Web, handle e-mail and run a yet-to-be-written library of downloaded applications. Oh, yes, and handle incoming calls flawlessly while executing any of these jobs.

In short, tomorrow's handset must do everything today's PC does, using far less board space and power, and without the help of a cadre of IT support staffers. Chip vendors say they have the multiprocessing hardware and software products to handle the job. However, engineers are only beginning to scratch the surface of the design issues these expectations are creating for what has become the largest unit-volume product in electronics today.

Seeking single processor

In this environment, handset designers are crying out for simplicity. The biggest component issue in handset design "is getting to a single-processor solution," said Jeff Hawkins, a pioneering designer of PDAs and cellular handsets who was recently named chief technology officer of Palm Inc. (Milpitas, Calif.).

In this week's In Focus, Texas Instruments Inc.'s Avner Goren asserts that a multiprocessing system-on-chip is indeed the goal and explains how designers should carefully partition tasks to the various hardware resources on such a chip. LSI Logic Corp. engineers Jitendra Rayala, Stephen Jarboe and Wei-Jei Son describe the requirements of a multiprocessing-savvy software layer that can task between DSP and CPU resources as needed. And Doug Grant, who works in business development for the RF and wireless group at Analog Devices Inc., details the company's next-generation Edge phone, which adds high-quality imaging and audio without sacrificing battery power.

And just when you thought marketers had shoehorned every conceivable feature into a handset, David Myers, co-founder and vice president of engineering at Dilithium Networks, suggests they forgot what could be the killer app-video telephony. The startup describes why and how this feature could successfully come to cellular networks even though it has yet to catch on in the less-challenging wired world.

Finally, Jim Tran, director of product management, and Shinichi Miyazaki, senior product manager, at Qualcomm CDMA Technologies provide a tutorial on an effort to design a direct-conversion radio, simplifying that aspect of the ever-more-complex RF portion of tomorrow's cell phone.

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