By Mitchell Lazarus, CommLawBlog, April 6, 2014
New technical rules for unlicensed 5-GHz will yield better device performance.
We hear a lot about the shortage of spectrum that wireless carriers need for delivering silly cat videos to our smartphones and tablets. Also in short supply, although it gets less attention, is spectrum used by "unlicensed" services like Wi-Fi and Bluetooth. Access to this spectrum is free: no multi-billion-dollar auctions. The chips that use it are inexpensive, despite sometimes being housed in pricey tablets. There are no monthly charges. These frequency bands carry far more data every day than do carrier-provided 3G and 4G data services.
Older forms of Wi-Fi used only a band at 5.8 GHz band or, much more commonly, a band at 2.4 GHz. Some newer Wi-Fi protocols can use either or both, or other sub-bands in the 5-GHz range -- whatever gives the best performance at a particular time and place. These technologies are amazingly good at working around interference, but still, can tolerate only so much congestion. A mathematical theorem sets the limit. As more of our devices send and receive more data, everybody's performance gets worse.
A recent FCC order will help.