| http://www.w3.org/ns/prov#value | - U.S. Pat. No. 5,404,570, to Charas et al, whose disclosure is incorporated herein by reference, describes a repeater system used between a base transceiver station (BTS), which is able to receive signals, and a closed environment such as a tunnel, which is closed off to transmissions from the BTS. The system down-converts a high radio-frequency (RF) signal from the BTS to an intermediate frequency
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