Wireless Systems Design

Entertainment Nears The Consumer Sweet Spot

To encourage the spread of wireless video into the average home, this WLAN chip set delivers reliability and affordability.

Many consider the wireless home to be the crowning achievement of the engineering future. Currently, numerous engineering companies are working on technologies that will enable wireless audio/video in such a home. Although very impressive innovations have reached the market, they've failed to hit the right price or performance points. In contrast, the new wireless-local-area-network (WLAN) chip set from Atheros Communications strives to achieve the right mix of throughput, range, quality of service (QoS), and cost. The goal of the AR5005VA is to meet the requirements for wireless video networking through a home in the 2004-to-2006 timeframe.

This chip set promises to sustain multiple DVD-quality links (6 to 8 Mbps each) or a combination of DVD-quality and high-definition-TV (19 to 24 Mbps) links through homes that are up to 6000 ft.2 Because it uses standard IEEE 802.11a/b/g technologies and 802.11e QoS, the AR5005VA also enables TVs to pull multimedia content from PCs.

To make it easy and economical to include wireless support in new and existing consumer-electronics products, the AR5005VA provides direct support for the video/audio chip sets that are used in high-definition TVs, digital TVs, digital video recorders, set-top boxes, and Windows Media Center devices. The chip set's multimedia support includes direct interfaces as well as MPEG-Transport Stream support, a host controller, and direct-memory-access (DMA) acceleration for chip sets from ALi/T-Square, ATI, NEC, and more. The AR5005VA also features an infrared (IR) modulator and repeater capability, which forwards the consumer's IR remote-control signals to a source device.

To extend range and improve robustness, the AR5005VA's receiver uses up to four antennas for receive combining. As a result, it takes advantage of the difference in radio signals that are available to multiple antennas. Using advanced signal processing, it combines those signals to improve signal strength and quality.

With products that use the AR5005VA chip set's transmit beamforming and multiple receive combining, consumers can use the wireless interface just as they would a wired connection. Receive combining focuses RF energy from the intended direction, while transmit beamforming focuses the energy to the intended direction. The combined technologies promise to increase the effective signal by up to roughly 10 dB.

Meanwhile, the chip set's QoS capabilities help it ensure quality video and audio delivery while simplifying product designs. Aside from its support of 802.11e, it incorporates some features that are demanded by consumer-electronics manufacturers. For example, hardware-packet jitter control gets rid of video glitches. MPEG packet aggregation supports higher-quality video. In addition, MPEG encapsulation transforms wireless to wired-style packets like 1394.

To comply with the specifications of the Digital Living Network Alliance (www.dlna.org), the chip set's MIPS R400-class processor also supports digital-rights-management (DRM) technology and MPEG encapsulation into other protocols. With this level of QoS, it becomes easier to adapt wired-video designs to a wireless environment.

For users, these features translate into the ability to view and organize PC-based photos and videos; play audio sources like MP3, Apple AAC, and Sony ATRAC files; and play video files from Windows Media Center devices. The chip set even vows to eliminate the signal cables that now connect wall-mounted flat-screen TVs.

The AR5005VA chip set is available in both two- and four-antenna digital-CMOS configurations. The four-antenna configuration costs under $19 in 10,000-unit quantities. Volume production is expected to begin in the fall.

Atheros Communications, Inc.
529 Almanor Ave., Sunnyvale, CA 94085-3512; (408) 773-5200, FAX: (408) 773-9940, www.atheros.com.

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