City Locates Interference Source—AT&T Cellular

After years of complaints by Oakland (Calif.) police officers and firefighters about poor radio reception, city officials now they’ve now traced some problems to interference from AT&T Wireless antenna sites. Specifically, certain AT&T cellular transmitters on 850 MHz that provide 2G service are interfering with the city’s trunked radio system. The system was installed by Harris Corp., and has suffered from dead spots and various outages over the past five years. Last month the city began a comprehensive analysis of the radio network, and discovered interfering signals. The city contacted the Federal Communications Commission (FCC), whose technicians confirmed that AT&T Wireless transmitters were the source. In particular, one tower was generating signals that created dead zones on the city’s P25 radio system. The FCC contacted AT&T Wireless, and last Saturday at midnight, the company shut down their 850 MHz transmitters at 16 tower sites in the city. City officials didn’t say if the shut-downs have solved the radio reception problems. However, they did say they will now test AT&T tower sites in adjacent cities for interference, and are working, “around the clock to identify additional sources of interference.” Read the city’s press release (pdf) for more information.