While the draft 802.11ac Wi-Fi specification offers faster data transmission speeds and greater bandwidth to support...
the ever-growing number of devices on the corporate network, enterprises are learning the standard's reliance on a higher frequency channel translates to a decrease in Wi-Fi wave range.
While the 801.11ac wireless protocol, or Gigabit Wi-Fi, holds the promise of 1.3 Gbps throughput and support for simultaneous high-definition streams, the protocol only operates in the 5GHz frequency. This wide channel provides 802.11ac with the room it needs to accomplish higher transmission speeds between devices and access points, but the 5GHz channel has less range than the more commonly used 2.4GHz channel.
The 802.11ac standard's use of the 5GHz frequency provides users with a cleaner connection, free from the interference sources in the crowded 2.4 GHz frequency from devices like Bluetooth headsets, microwave ovens and cordless phones, said Jason Owen, CEO of Amped Wireless, a Chino Hills, Calif.-based Wi-Fi vendor. But the 5GHz band has shorter wavelengths than 2.4GHz, so 802.11ac traffic is limited by how far the 5GHz channel can reach, Owen said.
Most enterprises have designed their networks based on the ranges offered by 2.4 GHz, and replacing a network with a standard that operates exclusively on 5GHz will inherently shorten signal range, said Jim Berenbaum, research director of mobility, wireless and network technologies for Stamford, Conn.-based Gartner Research Inc. "The range decreases because users won't get [802.11ac's] maximal speed rates at longer distances," he said.
Enterprise options for extending wireless signal range
Amped Wireless offers wireless range extender products for enterprise, small- to medium-sized business and consumer customers. The vendor recently announced its REA20 802.11ac Range Extender product, which boosts 802.11ac range.
The new REA20 802.11ac Range Extender stretches Wi-Fi signals up to 10,000 square feet for business customers, he said. Large, open office environments typically require two to three range extenders on average, then each extender can be chained together to increase range further.
"The advertised high speed of Gigabit Wi-Fi degrades very quickly, and are only possible from five to ten feet away from an [access point]," Owen said. "Keeping those fast speeds and range up for users is very important."
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Range extender products aren't the only answer to 5 GHz Wi-Fi band shortcomings. Beamforming, a method of sending out the same signal from multiple antennas on a single access point in order to determine the best path the signal should take to a client device, can also extend the effective range of 802.11ac access points, said Craig Mathias, principal at the Ashland, Mass.-based Farpoint Group advisory firm.
"Because of beamforming, I don't expect the market will see a large uptick in the range extender market." he said.
Previous Wi-Fi standards have supported both 2.4 and 5GHz channels, and 802.11ac range issues are less likely to affect enterprises who designed their network with both channels in mind, Gartner's Berenbaum said. "Enterprises will be able to start by using the same [access point] AP placement their legacy network used, and just do a swap with 802.11ac APs," he said.
Instead of replacing each legacy Wi-Fi access point, 802.11ac can be deployed by overlaying Gigabit Wi-Fi access points within the legacy environment, adding additional APs to high-traffic areas, he said. "Even as users move away and the signal drops off, the connection will still be better than what 802.11n was able to offer."
Will a shorter 802.11ac range affect the enterprise?
While the signal range for the wider 5GHz channel may be shorter than 2.4GHz, it won't be enough of an issue to interrupt 802.11ac adoption within the enterprise, Berenbaum said.
Enterprises today should be optimizing their environments for capacity, not for coverage, Farpoint's Mathias said. "The objective should be to commission a lot of capacity, and range is kept shorter," he said.
As demands on the Wi-Fi infrastructure increase with the addition of more applications and devices, enterprises will most likely need more APs. "APs will need to be more densely deployed -- regardless of the standard they are supporting," he said.