FAQ About Telecom Frequencies

There are several commonly used wireless frequencies encountered in business telecom environments. A brief outline of these frequencies and some problems with each are below.

  • 46 MHz - 47 MHz - The original cordless phone frequency in the United States introduced around 1980. Unfortunately, in addition to cordless phones, some walkie-talkies and baby monitors use the same frequency band. Not particularly secure if you had a model that didn't incorporate some kind of scrambling. Radio scanners and even neighbouring phones could pick up your conversation.

  • 902 MHz - 928 MHz - Commonly referred to as "900 MHz". While analog cordless phones in this frequency band can be picked up by radio scanners, models incorporating "Digital Spread Spectrum" (DSS) prevented this problem by transmitting on multiple frequencies in the frequency band. Because of the way DSS works, if you have one 900 MHz device with DSS and another without operating in the same general area, the device with DSS will "crowd out" the non-DSS device, resulting in interference and/or reduced range or no service at all.

  • 1.9 GHz - This is the newest frequency approved by the FCC. At the moment, it's a relatively uncluttered frequency band because so few wireless devices in business telecom use it. The first we know of is the Plantronics CS55 wireless phone headset.

  • 2.4 GHz - used by many cordless phone models and wireless devices (like wireless routers and cards in computers). Same problems with DSS models interfering with non-DSS models.

  • 5.8 GHz - another frequency band used for cordless phones. Much less interference with wireless computer devices, most of which operate at the 2.4 GHz range.