The Wi-Fi standards that have played a big role in changing the way in which people communicate are on the precipice of a jump that could make hotspots in crowded venues far more accessible.
Two interrelated concepts that are pushing Wi-Fi to new speeds are Multiple Input Multiple Output (MIMO) and beam forming. MIMO focuses on multiple transmissions of the same signal. Sophisticated computer techniques use what in essence are the good parts of each stream to increase speeds and enhance range. Beam forming allows the antenna to focus energy with precision and serve any given spot more effectively than in legacy approaches in which signals are dispatched in a 360-degree arc.
Equipment implementing these advances is gradually entering the market. Last week, IT World and other sites reported that Qualcomm is releasing chipsets that extend MIMO. The technology – the Qualcomm products are in the QCA family – has the even more awkward name of multiple user multiple input multiple output (MU-MIMO). Mikael Ricknäs does an exemplary job of explaining the limitations of early versions of MIMO and what MU-MIMO brings to the table:
The problem is that access points or wireless routers use short time slots to communicate with only one user at a time, and as more users get connected the network can get overloaded. MU-MIMO (multi user-multiple-input multiple-output) will help change that by letting networks transmit data to many users simultaneously.
Qualcomm announced chipsets enabling four data streams for network gear and two for consumer equipment.
A good backgrounder on MU-MIMO is offered in a video by Matthew Gast, the director of product management for Aerohive. The video goes through the concepts of single-user MIMO (SU-MIMO) and MU-MIMO.
Gast, thankfully, doesn’t get into the math. He describes beam forming as a powerful approach introduced in 802.1n. The idea is that a “null,” essentially empty, packet goes on sort of a digital reconnaissance mission to determine the location of the end user’s device. This provides the information that is needed to facilitate the MU-MIMO technology.
MU-MIMO probably will be the next hot thing in Wi-Fi. AnandTech reports that chip maker Quantenna includes the feature on the QSR1000 chipset. The story says that MU-MIMO is a part of Wave 2, or the second iteration of 802.11ac standards. It is possible to implement eight spatial streams, though vendors likely will stop at four. The piece also says that the Asus RT-AC87U is the first router to use QSR1000 technology.
The technology is likely to be in enterprise and consumer equipment next year. Dailywireless.org has more on the introductions of MU-MIMO devices that are available, at least as of the beginning of the year. The story leads off with the Asus router and offers a layperson-friendly explanation of what Wave 2 makes possible.
The bottom line is that Wi-Fi technology continues to grow more sophisticated. The good news is that the days of not being able to use Wi-Fi in a crowded venue may be numbered.