Cordless phones typically operate on two frequencies that may interfere with wireless connectivity since they are on the same frequency band–2.4 GHz and 5 GHz. If you find that the frequency of your cordless phone is interfering with your wireless signal, you may switch frequency levels on your phone or make modifications to your wireless network. In fact, according to NASA, it is best to use a 900 MHz or 2.4 GHz phone as it provides additional security and better reception than lower-frequency phones.
Determine what frequency your existing cordless phone operates on.
As specified in VTech's Cordless Phone Guide, cordless phones operate as a radio transmitter or receiver that operates across a designated frequency. The clarity and range of your phone vary based on this frequency; when possible, you should purchase a phone that is enabled with channel hopping as it increases the range of the phone and minimizes interference from other electronic devices. If your phone doesn't have this built-in functionality, you may manually change your phone's frequency.
The Federal Communications Commission determines the frequency of cordless phones that is made available to the public. There are currently three main frequencies used for cordless telephones: 900 MHz, 2.4 GHz, and 5.8 GHz. The higher the frequency, typically the less interference and greater the range of the phone. Additionally, there is increased security when using higher frequencies. However, interference and lack of clarity may occur on any cordless phone because of the use of other electronic devices in your home or in your area.
Manually change your phone's frequency.
Cordless phones come equipped with a "Channel" button that enables you to manually change the frequency of your phone. By changing the channel, you are able to switch the frequency and range of your phone. As reported by the Physics Department of the College of William & Mary, cordless telephones are equipped to allow you to change their frequency because the more individuals in an area who use these devices, the more interference you will have.
Purchase an antenna if unable to remove interference or still need to improve the clarity of your phone.
If your phone has built in channel-hopping and you have attempted to change your phone's frequency by using its "Channel" button to no avail, consider purchasing accessories that may help. There are antennas that may be used to improve the clarity and functionality of your cordless phone. Some bases that come with your cordless phones may have dual antenna connectors that enable you to mount two antennas on either side of a wall to improve clarity.