One of the reasons that observers I spoke to for a feature last month think 802.11n will be the final major entry to the 802.11 family-at least for the foreseeable future-is that it is extremely wide-ranging. At the low end, it is much faster than the 802.11a, b and g variants. At the upper end it approaches Usain Bolt territory by providing a virtual torrent of bandwidth.
The still unfinished (though virtually settled) spec offers several approaches that can combine to reach the high speeds. Perhaps the most important tool is the ability to use multiple transmit and receive antennas. Using four of each-short-handed as "4x4"-helps 802.11n reach a theoretical throughput of 600 Mbps.
Nothing comes for free, however. The more transmitters and receivers used, the higher the complexity and, ultimately, the cost. Thus, the highest of throughput levels wasn't a prime target of early developers. Now, however, work on 802.11n 4x4 is starting to percolate. Wi-Fi Net News reports that Qualcomm has announced a 4x4 chip, the N-Stream Wireless LAN WCN1320. It will be sent to manufacturers for sampling this month, though no announcement has been made on when products will be released.
This is not the only 4x4 entrant. In late April, Quantenna Communications announced that it had won $13.85 million in Series C funding from new and existing investors. The round was led by a new participant, Southern Cross Venture Partners, which placed its managing director on the Quentenna board of directors. The company, which has raised more than $42 million, aims to produce chips for home gateways, home routers, set-top boxes, televisions and other devices. Beam forming and 4x4 multiple-in multiple-out (MIMO) technology will wirelessly transmit high definition video and multimedia throughout homes.
It is easy to get lost in the intricacies of MIMO antennas, beam forming and the number of transmitters and receivers that are squeezed into devices. The fundamental fact should be emphasized over all the technical talk: The framers of 802.11n saw that there is no such thing as too much bandwidth, and aimed to create an extremely comprehensive standard able to reach very high throughput levels. The creation of chipsets that take advantage of the tools built into the standard is starting. The inevitable next step-release of actual products-won't be far behind.