A long time ago…

Think back to the year 1999.  The world was anticipating the new millennium, the financial industry was highly focused on “the Y2K bug”, and the Internet was entering its next phase of connectivity.

IEEE 802.11b was introduced in September 1999.  Boasting transfer speeds of up to 11 Mbps, this was the first widely adopted WLAN standard.

And it changed the world.

Now, over 10 years later, 802.11n leads the Wireless LAN market.  Transfer rates have jumped from 11 Mbps to 600 Mbps.  We have moved from simple WEP encryption to the almost unbreakable WPA2.  Initial setup, which used to be cumbersome, has mostly been replaced by WPS and the simple push of a button.

But how will this technology continue to change and evolve over the next 10 years?

In this series of articles, I will discuss trends in the Wireless LAN market and possible technologies to come. This first post explores the most important and perhaps the most fundamental need with the WLAN community: The Need for Speed.

The Need for Speed: Multi-streaming Technology

802.11n uses Multiple Input/Multiple Output technology.  MIMO allows multiple antennas to distribute separate communications channels, or streams, at both the transmitter and receiver to improve overall communication performance.  As the number of streams increase, the theoretical maximum transfer speed increases.

The current 802.11n standard is designed to achieve a theoretical maximum of 600 Mbps using 4 streams, each working at 150 Mbps.  802.11n products have mainly offered single or dual stream technology, with 3-stream products recently entering the market.

However, it remains to be seen if 3 or 4 stream products will lead the market, and here’s why:

A receiver will typically use either n or n+1 antennae, where n is the number of streams.  MIMO antennas need to be installed at about a 6cm spacing, so a higher order multi-stream MIMO device might end up with antennas poking out in multiple different directions.  This presents a very real industrial design problem, as well as a potential user installation problem.

And while sheet or chip style internal antennae are available for PCs and tablets, smaller devices, such as smart phones, don’t have enough internal space on the PCB to install antennas for multi-stream MIMO.  This potentially limits the technology to larger devices such as computers and home media equipment.

In summary, multi-streaming MIMO is capable of achieving higher sped transfer without a dramatic improvement of current technology.  However, there are significant difficulties for smaller, cheaper, or low-power products.

How do you think multi-streaming technology will evolve?  Put your theories in the comments section to continue the discussion.  

Next Time

Next up, I’ll discuss HT20/HT40 “wider-band” technology.  Until then you can connect with Silex Technology on Facebook, Twitter, Google+, or via email at sales@silexamerica.com to find out more on how Silex can help.