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Wireless Web appliances evolve anew

Posted: 01 Apr 2001 ?? ?Print Version ?Bookmark and Share

Keywords:wap? graphics accelerator? ofdm? asic? dsl?

One of the biggest limitations of Web tablets is that few are truly wireless-enabled. The primary reason for this is that the common wireless technologies for embedded platforms, such as Cellular Digital Packet Data and General Packet Radio Service, support a maximum data rate of 19.2Kbps and 150Kbps, respectively.

So protocols such as Wireless Application Protocol (WAP) are traditionally employed to strip the rich media content from the target website to alleviate painfully extended wait times. The result is a less than fulfilling Web experience.

Working together, wi-lan and Applied Data Systems have developed a new product that would offer a thousand-fold speed increase for wireless data transmission and would improve speeds from the current levels of 19Kbps and 27Kbps to 20Mbps.

We developed a wireless web pad equipped with Intel's SA-1110 microprocessor and SA-1111 companion chip, the MQ200 graphics accelerator, Windows Media 6.4, a 13.5-inch XGA TFT display and 20Mbps unprecedented access data rate. Two factors enabled us to do this: broadband communication data rates and multimedia processing.

Last year, Wi-LAN developed the OFDM ASIC for use in our WAN product line. Wideband OFDM (W-OFDM), a multi-carrier transmission scheme, offers two inherent advantages over other wireless techniques: the technology highly resists the effects of multipath delay spread and it boasts outstanding spectral efficiencies.

One of our primary goals was to develop a design that would sustain high-resolution, media-rich applications to differentiate our access technology from the existing technologies that support only limited bandwidth applications such as e-mail.

In the middle of 2000, Wi-LAN's team began focusing on a proof-of-concept design that would showcase the portability of the W-OFDM technology. The immediate challenge was to identify and select an embedded architecture-OS combination that was powerful enough to fully demonstrate the capabilities of W-OFDM. To do that, we defined an extensive list of selection criteria about the performance of existing embedded processors and OS.

Flexible processors

Selection criteria of embedded processors with greater flexibility greatly considered the power requirements; availability of design tools; vendor support; general component availability; number of previous design wins; support by credible design houses; highest cost-performance ratio; and the capabilities of supporting dominant OS-such as Windows CE and Windows Media.

Then we began searching for a partner with a solid track record developing embedded platforms for portable and mobile applications. Ultimately, we identified and evaluated five processors, three potential OSs and a number of competent vendors; we then assessed the existing platform offerings of each of the vendors. After four months of investigation, we brought in Applied Data Systems (ADS) as our partner.

Integration goal

Basically, ADS supplied the multimedia processing capabilities by integrating our technology with one of the only commercial off-the-shelf component technologies that could keep up with such a broad data pipe and still run on batteries. ADS adapted its StrongARM-powered Tandem product with the powerful Media-Q MQ-200 graphics processor.

We built an onboard power supply as part of the Tandem package to help speed the project's development. Finally, we had to add a slot to hold the PCI implementation of the Wi-LAN OFDM communication system.

Most important for our Web tablet application is that the Tandem system uses its RISC environment and streamlined engineering platform to produce minimal heat output and a power requirement of only several watts. ADS included an onboard power supply so that battery operation would be possible.

The Wi-LAN and ADS teams selected the Windows CE platform, as it represents one of the most dominantly known OS's in the embedded market today. To further simplify the tablet, we selected a two-board solution for the prototype?Wi-LAN's W-OFDM PCI module and a modified ADS Tandem system. The module design provides a PCI 2.1-compliant 32-bit, 33MHz interface into the OFDM engine that can provide up to 30Mbps of raw data.

In the Web tablet design, one of the problems our teams had to face was how to blend design elements of hardware, software and FPGA code while maintaining the portability of the existing software in the design. We wanted few changes as possible to the PCI FPGA design, since modification of a design that complex would certainly not be trivial.

? Michael Boryski

Product Manager

Wi-LAN Inc.

Pete Dombrowski

Senior Electrical Engineer

Lawrence Ricci

Business Development

Applied Data Systems Inc.

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