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Code of Federal Regulations (Last Updated: July 5, 2024) |
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Title 47 - Telecommunication |
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Chapter I - Federal Communications Commission |
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SubChapter D - Safety and Special Radio Services |
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Part 90 - Private Land Mobile Radio Services |
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Subpart M - Intelligent Transportation Systems Radio Service |
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Regulations Governing the Licensing and Use of Frequencies in the 5895-5925 Mhz Band for Dedicated Short-Range Communications Service (DSRCS) |
§ 90.377 - Frequencies available; maximum EIRP and antenna height, and priority communications.
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§ 90.377 Frequencies available; maximum EIRP and antenna height, and priority communications.
(a) Licensees shall transmit only the power (EIRP) needed to communicate with an On-Board Unit (OBU) within the communications zone and must take steps to limit the Roadside Unit (RSU) signal within the zone to the maximum extent practicable.
(b) Frequencies available for assignment to eligible applicants within the 5850-5925 MHz band for RSUs and the maximum EIRP permitted for an RSU with an antenna height not exceeding 8 meters above the roadway bed surface are specified in the table below. Where two EIRP limits are given, the higher limit is permitted only for state or local governmental entities.
Channel No. Frequency range
(MHz)Max. EIRP1
(dBm)Channel use 170 5850-5855 Reserved. 172 5855-5865 33 Service Channel.2 174 5865-5875 33 Service Channel. 175 5865-5885 23 Service Channel.3 176 5875-5885 33 Service Channel. 178 5885-5895 33/44.8 Control Channel. 180 5895-5905 23 Service Channel. 181 5895-5915 23 Service Channel.3 182 5905-5915 23 Service Channel. 184 5915-5925 33/40 Service Channel.4 (c) Except as provided in paragraphs (d) and (e) of this section, non-reserve DSRCS channels are available on a shared basis only for use in accordance with the Commission's rules. All licensees shall cooperate in the selection and use of channels in order to reduce interference. This includes monitoring for communications in progress and any other measures as may be necessary to minimize interference. Licensees of RSUs suffering or causing harmful interference within a communications zone are expected to cooperate and resolve this problem by mutually satisfactory arrangements. If the licensees are unable to do so, the Commission may impose restrictions including specifying the transmitter power, antenna height and direction, additional filtering, or area or hours of operation of the stations concerned. Further the use of any channel at a given geographical location may be denied when, in the judgment of the Commission, its use at that location is not in the public interest; use of any such channel may be restricted as to specified geographical areas, maximum power, or such other operating conditions, contained in this part or in the station authorization.
(d) Safety/public safety priority. The following access priority governs all DSRCS operations:
(1) Communications involving the safety of life have access priority over all other DSRCS communications;
(2) Subject to a control channel priority system management strategy (see ASTM E2213-03 DSRC Standard at § 4.1.1.2(4)), DSRCS communications involving public safety have access priority over all other DSRC communications not listed in paragraph (d)(1) of this section. Roadside Units (RSUs) operated by state or local governmental entities are presumptively engaged in public safety priority communications.
(e) Non-priority communications. DSRCS communications not listed in paragraph (d) of this section, are non-priority communications. If a dispute arises concerning non-priority communications, the licensee of the later-registered RSU must accommodate the operation of the early registered RSU, i.e., interference protection rights are date-sensitive, based on the date that the RSU is first registered (see § 90.375) and the later-registered RSU must modify its operations to resolve the dispute in accordance with paragraph (f) of this section.
(f) Except as otherwise provided in the ASTM-DSRC Standard (see § 90.379) for the purposes of paragraph (e) of this section, objectionable interference will be considered to exist when the Commission receives a complaint and the difference in signal strength between the earlier-registered RSU and the later-registered RSU (anywhere within the earlier-registered RSU's communication zone) is 18 dB or less (co-channel). Later-registered RSUs causing objectionable interference must correct the interference immediately unless written consent is obtained from the licensee of the earlier-registered RSU.
[71 FR 52749, Sept. 7, 2006, as amended at 72 FR 35199, June 27, 2007]