What specific technologies are required in compliant signal boosters to prevent interference

* Network Protection Standards Compliant signal boosters must adhere to existing technical parameters for power and unwanted emissions in the applicable spectrum band[4].
* Self-Monitoring Signal boosters should automatically monitor their operations to ensure they comply with applicable noise and gain limits. If the booster isn't compliant with FCC technical rules, it should automatically shut down[4].
* Oscillation Detection and Mitigation The booster needs to automatically detect and mitigate oscillations in the uplink and downlink bands[4]. This prevents unintended oscillations that may arise from insufficient isolation between antennas[4].
* Automatic Power Down Signal boosters must automatically power down or cease amplification when a device is not needed, such as when the device approaches the base station it is communicating with[4].
* Interference Avoidance For internal operations, mobile phone repeaters that use unlicensed frequency bands for wireless transmissions between donor and server subsystems must employ interference avoidance methods to prevent interference transmitted into other spectrum bands[4].
* Gain Control Mobile phone repeaters must have automatic gain control to guard against excessive input signals that could produce output power emissions, which could interfere with a mobile base station. Also, they should adjust their gain according to the strongest signal present in the downlink band of operation so that the repeater's noise cannot reach the base station[4].
* FCC Certification In the United States, the Federal Communications Commission (FCC) regulates mobile signal boosters and requires that all signal boosters be certified before use[6]. This certification ensures that the boosters do not cause interference with cellular networks[6].
* Provider Consent and Registration Subscribers are required to obtain provider consent to operate the booster and register the booster with their provider[4].