A cell phone jammer is a simple tool that broadcasts noise interference on the radio frequency being used by the cell phone. While effective in many cases, it can be quite easy to get around cell phone jammer signals.
Use proximity avoidance. Typical cell phone jamming systems are meant to reach distances of approximately 30 feet. Drive or walk away from the jammed area to receive calls.
Use a quad-band cell phone with multiple frequencies. Since most jammers only block one frequency, you will be able to use one of your phone's alternate frequencies. Note that advanced jammers block multiple frequencies at one time.
Use VoIP on your cell phone to make calls over a Wi-Fi network and bypass radio frequencies. One such VoIP program is Skype, which offers compatibility for many types of cell phones.
Use your device's data plan. Data plans such as 3G and EV-DO use different frequencies than standard calling.
Quad-band cell phone service is available only available on certain carriers.