How do mobile phone repeaters prevent harmful interference to wireless networks

Technical Requirements
* Self-Monitoring Mobile phone repeaters are equipped to automatically self-monitor their operation. This ensures they adhere to noise and gain limits, and they are designed to either self-correct or shut down if they exceed these parameters[3].
* Anti-Oscillation Mobile phone repeaters can detect and mitigate unintended oscillations in uplink and downlink bands, which might occur due to insufficient isolation between antennas[3]. Some repeaters include anti-oscillation features that detect feedback conditions and reduce gain to maintain stability[3].
* Power Down These repeaters are designed to automatically power down or cease amplification as they approach any affected base station[3].
* Interference Avoidance Mobile phone repeaters using unlicensed frequency bands for wireless transmissions between donor and server subsystems must employ interference avoidance methods to prevent interference transmitted into other spectrum bands[3].
* Automatic Standby When the repeater is not serving an active device connection, it reduces uplink noise power to specified levels after a short period[3]. For indoor use, this reduction occurs after no more than 5 minutes, reducing uplink noise power to no more than −70 dBm/MHz EIRP. The same is true for vehicular use[3].
* Gain Control Mobile phone repeaters use automatic gain control to guard against excessive input signals that could lead to output power emissions causing interference to a mobile base station[3]. They adjust gain according to the strongest signal present in the downlink band of operation to prevent repeater noise from reaching the base station[3].

Additional Considerations
* Spurious Emissions Spurious emissions are signals generated internally within the repeater that could cause interference. These signals, particularly those within the operating band, are amplified and can lead to greater levels of interference[3].
* Distortion and Delay Repeaters can introduce distortion and delay to signals, which, if excessive, can cause bit errors and reduce the quality of service. While simple repeaters introduce minimal delay, smart repeaters with more complex signal processing may introduce longer delays, potentially reducing the cell's maximum range[3].
* Signal Amplification By amplifying existing cellular signals rather than creating them, signal boosters minimize interference[6].