FCC Proposes Faster, Higher Capacity WiFi to Reduce Spectrum Crunch

 
 
By Wayne Rash  |  Posted 2013-01-13
 
 
 

FCC Proposes Faster, Higher Capacity WiFi to Reduce Spectrum Crunch


The idea of a faster, higher-capacity WiFi sounds great, doesn’t it? But right now the best you can do, realistically, in public places is to access 802.11n WiFi and hope for the best. Unfortunately, in busy sites such as airports, trade shows or even in offices with a lot of wireless traffic, that may not be good enough to provide reliable wireless connections.

Fortunately, that may change. Federal Communications Chairman Chairman Julius Genachowski said he wants to give more spectrum to WiFi to enable broader availability of “Gigabit WiFi.” The idea would be to either reassign portions of the 5 GHz band or share it with other users to enable a larger number of WiFi channels and thus provide more bandwidth.

“We all know the frustration of WiFi congestion at conferences and airports,” Genachowski said during an interview with Gary Shapiro, president of the Consumer Electronics Association during an event at the Consumer Electronics Show in Las Vegas on Jan. 9.

“Today, the FCC is moving to bring increased speed and capacity to WiFi networks by increasing the amount of unlicensed spectrum for WiFi. As this spectrum comes on line, we expect it to relieve congested WiFi networks at major hubs like convention centers and airports. It will also help in homes as tablets and smartphones proliferate and video use rises.”

Genachowski said that the FCC would begin a governmentwide effort to improve WiFi by increasing spectrum by 35 percent. Genachowski said the FCC would add an additional 195 megahertz to the existing 5 GHz WiFi spectrum. An FCC spokesperson said in a prepared statement this is the largest expansion of unlicensed spectrum since 2003.

While the opening up of new WiFi frequencies will eventually reduce WiFi congestion, don’t expect it to make your iPad run faster next month. Spectrum availability is just the first step in providing faster WiFi. Once it’s available, makers of routers and access points have to upgrade their products to use the added capacity and speed. Then the makers of laptops, smartphones, tablets and all other wireless devices have to follow suit.

As is the case with other improvements in WiFi, the whole process can take years. A good example is the new gigabit WiFi standard 802.11ac. Right now, this is a draft standard. But the first routers have already hit store shelves. Once the standard is finalized, these devices should be able to be upgraded to take advantage of the additional bandwidth.

But right now there aren’t any 802.11ac devices on the market except for the routers. And the devices that are available now don’t work at those gigabit speeds you keep hearing about.

FCC Proposes Faster, Higher Capacity WiFi to Reduce Spectrum Crunch


In fact, 802.11ac routers don’t really operate at gigabit speeds, despite being theoretically capable. The reality is these devices are limited in what they can do. Right now, the only way to use 802.11ac is to buy two devices, a router and either a media bridge or another router to connect with wired Gigabit Ethernet.

Even when a true 802.11ac connection is established, the real Layer 7 (that’s the application networking layer that you would use for streaming audio or video) throughput is more on the order of 300 to 400M bps or fewer depending on the distance between the devices, interference and other factors. But for WiFi to work even at these speeds, you need a MIMO antenna system that handles at least three spatial streams on both ends. These antennas take up a fair amount of space, a reason you don’t see them on your iPhone.

What the FCC is proposing is really a larger number of 802.11ac channels, which in turn means a larger number of available 5 GHz channels. By having a greater number of channels, you’ll have less likelihood of WiFi congestion and you’ll be able to have more people using faster WiFi. But there are two things that will keep even this from happening right away.

First, the only way these WiFi channels can be used is if the devices using them have a way to access the new channels. Right now, even devices that work with 802.11n are limited to existing channels. Perhaps some devices have radios that can be tuned to new frequencies through a software upgrade, but I suspect most don’t.

Second, those devices have to support gigabit WiFi, including the MIMO antenna systems and the greater data rates. There are WiFi adapters that will support two spatial streams, but that’s it. Because antenna design is limited by the laws of physics, the third antenna has to go somewhere, and it’s not clear where there’s space in a handheld device.

Of course, some devices will be able to support the necessary hardware. Some laptop computers already have those MIMO antennas built in and can support three spatial streams. Most tablets could do that as well. But it’s going to be tough for smartphones to support the new standards.

So the reality is the new bandwidth will free up capacity, which is good. But it will be awhile. And it will be a lot longer before you’re using your smartphone at gigabit speeds.

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