(4) Local Service Area of a Primary Transmitter.—The “local service area of a primary transmitter”, in the case of both the primary stream and any multicast streams transmitted by a primary transmitter that is a television broadcast station, comprises the area where such primary transmitter could have insisted upon its signal being retransmitted by a cable system pursuant to the rules, regulations, and authorizations of the Federal Communications Commission in effect on April 15, 1976, or such station’s television market as defined in section 76.55(e) of title 47, Code of Federal Regulations (as in effect on September 18, 1993), or any modifications to such television market made, on or after September 18, 1993, pursuant to section 76.55(e) or 76.59 of title 47, Code of Federal Regulations or within the noise-limited contour as defined in 73.622(e)(1) of title 47, Code of Federal Regulations, or in the case of a television broadcast station licensed by an appropriate governmental authority of Canada or Mexico, the area in which it would be entitled to insist upon its signal being retransmitted if it were a television broadcast station subject to such rules, regulations, and authorizations. In the case of a low power television station, the “local service area of a primary transmitter” comprises the area within 35 miles of the transmitter site, except that in the case of such a station located in a standard metropolitan statistical area which has one of the 50 largest populations of all standard metropolitan statistical areas (based on the 1980 decennial census of population taken by the Secretary of Commerce), the number of miles shall be 20 miles. The “local service area of a primary transmitter”, in the case of a radio broadcast station, comprises the primary service area of such station, pursuant to the rules and regulations of the Federal Communications Commission.