The key to Wi-Fi’s success has been its huge flexibility, going well beyond its original remit as a local area network to support everything from outdoor metrozones to in-home superfast content networks. The latter market is the main focus of Wi-Fi R&D this year, with the community aiming to set standards for the emerging 60GHz band and to push existing 802.11n systems to their limit, performance-wise, to support HD video and other important home applications. The past week has seen two contributions to this effort, from start-up Quantenna and established WLan chip major Atheros.
Transmitting high definition video round the home wirelessly is a key goal of the consumer electronics industry. Much of the recent attention has focused on developments in the uncongested 60GHz band, which supports very high speeds but has range challenges. Various companies are focusing instead on the more conventional 5GHz Wi-Fi band to achieve similar results. One of these start-ups, Quantenna Communications, has announced commercial availability of the QHS600, the third generation of its two-year old platform, which uses 4×4 MIMO antenna arrays.
Meanwhile, Atheros is taking a slightly different approach. Unlike Qualcomm, it is stopping at 3×3 MIMO at this stage, but has pushed the data rate of its 802.11n chipset to a peak of 450Mbps with its latest release.
The new AR938x and AR9390 chipsets support the fast Wi-Fi standard, 802.11n, and MIMO. Leveraging these two technologies in a standard way delivers greater spectral efficiency and more consistent performance even further away from the access point, by using techniques like multiple spatial streams (separately encoded signals within one channel). However, Atheros is adding its own enhancements, notably the use of three rather than two spatial streams. This boosts peak 11n data rate from 300Mbps to a claimed 400Mbps.
The chipmaker says its new offerings will be similarly priced to the previous generation. Even greater speed and reliability will be supported by other techniques, such as transmit beamforming ‘ an option within the 11n standard – and more efficient error correction coding. Atheros is also using ‘maximum likelihood’ equalization algorithms to demodulate the received signal more accurately. The combination of all these enhancements can achieve 50% better range or 65% higher effective bandwidth than previous generation solutions, says the vendor.
It also says the various advances are better suited to multimedia streaming, a key application for Wi-Fi in the home. For instance, algorithms search for unused radio channels for the video stream and the chipsets are designed to support three simultaneous HD video streams.
Also favoring the 5GHz band over the more experimental 60GHz, for now at least, is one of the many would-be standards for future HD wireless media networks, WHDI. This appeared to have been sidelined recently when two 60GHz groups, WirelessHD and WiGig, announced an alliance. But the WHDI group has come back fighting, with its latest specs and its own Wi-Fi integration strategy.
The group supporting WHDI (Wireless Home Digital Interface) says release 2.0 of its system will be released in the second quarter of 2011. Among its highlights will be full 3D support; reduced power consumption to aid mobile device integration; and compliance with the next generation HD format, 4Kx2K. Perhaps most importantly for its potential acceptance by major consumer electronics and mobile vendors, it is greatly enhancing integration with Wi-Fi, the dominant existing in-home network.
There are still real opportunities for all the major contenders for wireless HD content networks to score with chipmakers and OEMs, most of which are flirting with at least two of the options. The attitude of the Wi-Fi community will be vital, and the WiGig Alliance is the key body ‘ its technology is based on an extension of 802.11, emerging from the IEEE’s VHT (Very High Throughput) initiative. It is targeting the 60GHz spectrum band, and recently formed an alliance with 60GHz rival group WirelessHD, which uses technology pioneered by start-up SiBeam. That firm will create hybrid WirelessHD/WiGig silicon.
The main start-up behind WHDI is Amimon, which uses the more conventional 5GHz frequency to deliver uncompressed HD video. The company’s CEO Yoav Nissan-Cohen has said it will keep a watching brief on 60GHz but does not see it as ready for primetime yet. By contrast with efforts in that band, he argues, WHDI 2.0 will deliver essential ingredients of the next generation digital home within a year ‘ notably full 3D and higher data throughput. The Wi-Fi features will enable the two standards to coexist simultaneously in the same channel, Nissan-Cohen told EETimes.