47 CFR § 74.635 - Unattended operation.
(a) TV relay stations, TV translator relay stations, TV STL stations, and TV microwave booster stations may be operated unattended under the following conditions:
(1) The transmitter must be provided with adequate safeguards to prevent improper operation.
(2) The transmitter shall be so installed and protected that it is not accessible to other than duly authorized persons;
(3) TV relay stations, TV STL stations, TV translator relay stations, and TV microwave booster stations used with these stations, shall be observed at the receiving end of the microwave circuit as often as necessary to ensure proper station operation by a person designated by the licensee, who must institute measures sufficient to ensure prompt correction of any condition of improper operation. However, an STL station (and any TV microwave booster station) associated with a TV broadcast station operated by remote control may be observed by monitoring the TV station's transmitted signal at the remote control point. Additionally, a TV translator relay station (and any associated TV microwave booster station) may be observed by monitoring the associated TV translator station's transmitted signal.
(b) The FCC may notify the licensee to cease or modify operation in the case of frequency usage disputes, interference or similar situations where such action appears to be in the public interest, convenience and necessity.