--- kind: "range" citation: "47 C.F.R. §§ 24.129–24.135" title: "47" from: "24.129" to: "24.135" count: 7 url: "https://uscodex.org/cfr/47/24.129..24.135" --- # §24.129. Frequencies. The following frequencies are available for narrowband PCS: - (a) **Eighteen frequencies are available for assignment on a nationwide basis as follows—** - (1) **Seven 50 kHz channels paired with 50 kHz channels—** - (2) Three 50 kHz channels paired with 12.5 kHz channels: - (3) **Two 50 kHz unpaired channels—** - (4) **One 100 kHz unpaired channel—** - (5) **Two 150 kHz channels paired with 50 kHz channels—** - (6) **Three 100 kHz channels paired with 50 kHz channels—** - (b) **Five frequencies are available for assignment on a regional basis as follows—** - (1) **One 50 kHz channel paired with 50 kHz channel—** - (2) Four 50 kHz channels paired with 12.5 kHz channels: - (c) **Seven frequencies are available for assignment on an MTA basis as follows—** - (1) **Three 50 kHz unpaired channels—** - (2) **One 50 kHz channel paired with 50 kHz channel—** - (3) **One 100 kHz channel paired with 50 kHz channel—** - (4) **One 150 kHz channel paired with 50 kHz channel—** - (5) One 100 kHz channel paired with 12.5 kHz channel: # §24.130. Reserved # §24.131. Authorized bandwidth. The authorized bandwidth of narrowband PCS channels will be 10 kHz for 12.5 kHz channels and 45 kHz for 50 kHz channels. For aggregated adjacent channels, a maximum authorized bandwidth of 5 kHz less than the total aggregated channel width is permitted. # §24.132. Power and antenna height limits. - (a) Stations transmitting in the 901-902 MHz band are limited to 7 watts e.r.p. - (b) Mobile stations transmitting in the 930-931 MHz and 940-941 MHz bands are limited to 7 watts e.r.p. - (c) Base stations transmitting in the 930-931 MHz and 940-941 MHz bands are limited to 3500 watts e.r.p. per authorized channel and are unlimited in antenna height except as provided in [paragraph (d)](#d) of this section. - (d) - (1) MTA and regional base stations located between 200 kilometers (124 miles) and 80 kilometers (50 miles) from their licensed service area border are limited to the power levels in the following table: - (2) For heights between the values listed in the table, linear interpolation shall be used to determine maximum e.r.p. - (e) MTA and regional base stations located less than 80 kilometers (50 miles) from the licensed service area border must limit their effective radiated power in accordance with the following formula: - (f) All power levels specified in this section are expressed in terms of the maximum power, averaged over a 100 millisecond interval, when measured with instrumentation calibrated in terms of an rms-equivalent voltage with a resolution bandwidth equal to or greater than the authorized bandwidth. - (g) Additionally, PCS stations will be subject to any power limits imposed by international agreements. # §24.133. Emission limits. - (a) The power of any emission shall be attenuated below the transmitter power (P), as measured in accordance with [§ 24.132(f)](/cfr/47/24.132.md?p=f), in accordance with the following schedule: - (1) **For transmitters authorized a bandwidth greater than 10 kHz—** - (i) On any frequency outside the authorized bandwidth and removed from the edge of the authorized bandwidth by a displacement frequency (fd in kHz) of up to and including 40 kHz: at least 116 Log10 ((fd + 10)/6.1) decibels or 50 plus 10 Log10 (P) decibels or 70 decibels, whichever is the lesser attenuation; - (ii) On any frequency outside the authorized bandwidth and removed from the edge of the authorized bandwidth by a displacement frequency (fd in kHz) of more than 40 kHz: at least 43 + 10 Log10 (P) decibels or 80 decibels, whichever is the lesser attenuation. - (2) **For transmitters authorized a bandwidth of 10 kHz—** - (i) On any frequency outside the authorized bandwidth and removed from the edge of the authorized bandwidth by a displacement frequency (fd in kHz) of up to and including 20 kHz: at least 116 × Log10 ((fd + 5)/3.05) decibels or 50 + 10 × Log10 (P) decibels or 70 decibels, whichever is the lesser attenuation; - (ii) On any frequency outside the authorized bandwidth and removed from the edge of the authorized bandwidth by a displacement frequency (fd in kHz) of more than 20 kHz: at least 43 + 10 Log 10 (P) decibels or 80 decibels, whichever is the lesser attenuation. - (b) The measurements of emission power can be expressed in peak or average values provided they are expressed in the same parameters as the transmitter power. - (c) When an emission outside of the authorized bandwidth causes harmful interference, the Commission may, at its discretion, require greater attenuation than specified in this section. - (d) The following minimum spectrum analyzer resolution bandwidth settings will be used: 300 Hz when showing compliance with paragraphs [(a)(1)(i)](#a-1-i) and [(a)(2)(i)](#a-2-i) of this section; and 30 kHz when showing compliance with paragraphs [(a)(1)(ii)](#a-1-ii) and [(a)(2)(ii)](#a-2-ii) of this section. # §24.134. Co-channel separation criteria. The minimum co-channel separation distance between base stations in different service areas is 113 kilometers (70 miles). A co-channel separation distance is not required for the base stations of the same licensee or when the affected parties have agreed to other co-channel separation distances. # §24.135. Frequency stability. - (a) The frequency stability of the transmitter shall be maintained within ±0.0001 percent (±1 ppm) of the center frequency over a temperature variation of −30 °Celsius to + 50 °Celsius at normal supply voltage, and over a variation in the primary supply voltage of 85 percent to 115 percent of the rated supply voltage at a temperature of 20 °Celsius. - (b) For battery operated equipment, the equipment tests shall be performed using a new battery without any further requirement to vary supply voltage. - (c) It is acceptable for a transmitter to meet this frequency stability requirement over a narrower temperature range provided the transmitter ceases to function before it exceeds these frequency stability limits.