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Mythbusters: There’s No Interference at 5 GHz

April 17, 2012 - 0 Comments

A wireless network has become almost mandatory for every small business. A wireless network is relatively easy for non-technical people to install, and it’s convenient for users, who can use it to connect to the network and the Internet from anywhere in the building. But Wi-Fi does present a challenge that’s unique to the radio signals it uses to transmit data: interference. In this Mythbusters post, we’ll clear up the misconception that there’s no interference on the 5GHz channel.

A Wi-Fi network can use one of two frequency bands to send and receive radio waves: 2.4 GHz and 5 GHz. These frequencies are much higher than those used for other radios, like cell phones and walkie-talkies, so the Wi-Fi signal can carry considerably more data. All Wi-Fi networks use the wireless 802.11 networking standard; the difference is in which band you set your wireless router or access point to transmit on. 802.11b and 802.11g operate at the 2.4 GHz band, while 802.11a transmits at 5 GHz. Unlike the other variations of the standard, 802.11n can operate at both bands.

The 2.4 GHz band is heavily used and very crowded, in part because it provides only three non-overlapping channels. Also, products based on 802.11b have been less expensive than those based on the other wireless networking standards. The more crowded the frequency band, the more interference users are likely to experience from other devices, like cordless phones, Bluetooth devices, the neighbors’ Wi-Fi networks, and even the microwave oven in your break room.

The 5 GHz band with 23 non-overlapping channels provides cleaner reception with less interference. Also, knowing that the 5 GHz band has been less heavily trafficked, more and more small businesses have been moving their wireless networks to that frequency, expecting to find zero interference and a more reliable Wi-Fi network.

It’s true that fewer devices currently operate on 5 GHz, but there are enough now to cause some interference. Wi-Fi network components transmit data on this band along with radar and digital satellites. In short, you’re not as alone as you think on the 5 GHz band.

You can expect the 5 GHz band to get increasingly crowded. But that’s no reason to give in to interference on either band. You can work around Wi-Fi interference with a dual-band router, like the Cisco RV220W or the Cisco 891 Integrated Services Router; this kind of wireless device supports either the 2.4 or the 5 GHz bands. You can route traffic on the band of your choice based on which one is experiencing the least amount of interference. Some dual-band routers, like the Cisco 1800 Integrated Services Router, offer simultaneous operation, so the router automatically transmits traffic on the least congested band.

A Wi-Fi network is a no-brainer, but which frequency you set your router to isn’t necessarily obvious. Both the 2.4 GHz and the 5 GHz channel offer benefits and disadvantages. But if you monitor your wireless network performance and take steps to mitigate interference, such as using an RF analysis tool to seek out interfering devices, you can ensure users have a sound connection to the network.

What kind of wireless performance have you experienced on the 5 GHz Wi-Fi frequency band?

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