As a worldwide, unlicensed radio spectrum, the 2.4 GHz and 5 GHz bands allow virtually anyone to extend the range of networks with wireless access points. In spite of such universal availability, the unlicensed bands face problems from crowded use and inefficient channel assignments; both of which lead to increased co-channel interference. Faced with these issues, wireless administrators must pay close attention to details in order to plan for the most effective, efficient wireless network possible.
In the past, the 2.4 GHz band has been favored over 5 GHz due to its propagation characteristics. 2.4 GHz waveforms pass more easily through walls and reach clients at long distances. Over time however, the small range of unlicensed spectrum (approximately 83.5 MHz) belonging to the 2.4 GHz band has become overcrowded with competing access points. Furthermore, a prevalence of consumer devices (ex. cordless telephones, baby monitors, Bluetooth devices) using the same frequency range as the 2.4 GHz spectrum is considered ‘saturated.’
Compared to the 2.4 GHz spectrum, 5 GHz offers much more flexibility for wireless operators due to greater availability of spectrum and relaxed transmission power requirements. Although the 2.4 GHz band only allows for 3 reuse channels without overlap (1, 6 and 11), the 5 GHz band allows for as many as 24, depending on region (36, 40, 149, 153, etc.). Given the abundance of available channels and short-range propagation characteristics, high-density WLANs benefit greatly from the 5 GHz band.
