David Carey
TechOnline

The Phone Edition smart-phone hybrid from Voicestream/T-Mobile is a promising but still somewhat flawed step toward pocket-friendly "any kind, anytime, anywhere" communications. The design also telegraphs a potential for new players to upset the power balance as smart-phone components become merchant market items.

Sold outside the United States as the XDA and manufactured by Taiwanese OEM High Tech Computer (HTC), the Phone Edition can rightfully claim tight integration of phone and PDA form and function. GSM voice calls, SMS short-message service, wireless e-mail and desktop-like Web browsing are supported along with all traditional synchronizing PDA features. Product size is similar to that of traditional phoneless PDAs, the result of a single-board construction snugly layered between the front-lit touchscreen LCD and 4-mm-thick planar lithium-ion battery.

The PDA architecture centers on Intel's StrongArm SA-1110 processor, still a generation behind the announced PXA family from Intel and TI's competing Open Multimedia Applications Platform (Omap). Winbond SDRAM and Intel flash provide volatile and nonvolatile system memory, respectively. Digital PDA electronics are finished out with a Sony LCD module and LCD driver chip and what appears to be a mixed-interface ASIC by HTC.

TI dominates the GSM/GPRS radio path from logic to transceiver. A custom-labeled TI baseband chip is tied to a TI TRF6053 direct-conversion radio transceiver, 4 Mbytes of Intel flash for code storage, and a TI power management chip. A Silicon Labs Si4133 has been repackaged by TI as the TRF2053 for the (CMOS) RF synthesizer. A Conexant power amp module handles final-stage RF transmission. The relatively low component count highlights simplification in basic GSM/GPRS circuitry-an enabling factor for OEMs like HTC to enter the wireless fray.

Individual electronic subsections are shielded under snap-off cans to address RF sources and sensitivities from circuit activity and the required regulatory approvals. The internal battery is adhesively bonded to the plastic housing.

But the Microsoft PocketPC-powered Phone Edition shows serious growing pains. Irritating and sometimes unfathomable bugs require frequent warm and cold reboots. More integrated "communicative PDAs" will certainly follow from the Phone Edition through increased logic coupling and other architectural consolidation. But along with cheaper hardware, stable system behavior will be needed to sell the traditional phone user on a wireless-data-enriched PDA upgrade.

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DAVID CAREY IS CEO OF PORTELLIGENT (AUSTIN, TEXAS; WWW.PORTELLIGENT.COM), WHICH DOES TEARDOWN REPORTS ON PORTABLE ELECTRONIC SYSTEMS.