Dual-Band Wireless Networking Explained

Two frequency bands offer advantages over single-band networks

The Wireless Connection
The Wireless Connection

In wireless networking, dual-band equipment is capable of transmitting in either of two different standard frequency ranges. Modern Wi-Fi home networks feature dual-band broadband routers that support both 2.4 GHz and 5 GHz channels.

First-generation home network routers produced during the late 1990s and early 2000s contained a single 802.11b Wi-Fi radio operating on the 2.4 GHz band. At the same time, a significant number of business networks supported 802.11a (5 GHz) devices.

The first dual-band Wi-Fi routers were built to support mixed networks having both 802.11a and 802.11b clients.

Starting with 802.11n, Wi-Fi standards began including simultaneous dual-band 2.4 GHz and 5 GHz support as a standard feature. This inclusion means that nearly every modern router is considered a dual-band router.

Benefits of Dual-Band Wireless Networking

Linksys WRT55AG - Dual-Band Wireless A+G Broadband Router

By supplying separate wireless interfaces for each band, dual-band 802.11n and 802.11ac routers provide maximum flexibility in setting up a home network. Some home devices require the legacy compatibility and greater signal reach that 2.4 GHz offers while others may require the additional network bandwidth that 5 GHz offers.

Dual-band routers provide connections designed for the needs of each. Many Wi-Fi home networks suffer from wireless interference arising from the prevalence of 2.4 GHz consumer gadgets, like microwave ovens and cordless phones, all of which can only operate on three non-overlapping channels. The ability to use 5 GHz on a dual-band router helps avoid these problems because the technology supports 23 non-overlapping channels.​

Dual-band routers also incorporate Multiple-In Multiple-Out radio configurations. The combination of several radios on one band together with dual-band support provide much higher performance for home networking than what single-band routers can offer.

Dual-Band Wireless Routers

For homes that have many competing wireless devices, Google Wi-Fi is considered one of the top router choices. Its system consists of three satellites, called Wi-Fi points, each of which covers 1,500 square feet for a whopping total of 4,500 square feet of blanketed coverage. It uses beam-forming technology, which automatically routes devices to the strongest signal. 

Dual-Band Wi-Fi Adapters

Dual-band Wi-Fi network adapters contain both 2.4 GHz and 5 GHz wireless radios, similar to dual-band routers.

In the early days of Wi-Fi, some laptop Wi-Fi adapters supported both 802.11a and 802.11b/g radios so that a person could connect their computer to business networks during the workday and home networks on nights and weekends. Newer 802.11n and 802.11ac adapters can also be configured to use either band, but not both at the same time.

Dual-Band Phones

Similar to dual-band wireless network equipment, some cell phones also use two or more bands for cellular communications separate from Wi-Fi. Dual-band phones were originally created to support 3G GPRS or EDGE data services on 0.85 GHz, 0.9 GHz or 1.9 GHz radio frequencies.

Phones sometimes support tri-band or quad-band cellular transmission frequency ranges to maximize compatibility with different kinds of phone networks — helpful while roaming or traveling. Cell modems switch between different bands but do not support simultaneous dual-band connections.