MURS Rules - MMI Technical Resource

95.601	Basis and purpose
95.603	Certification required
95.605	Certification procedures
95.631	Emission types
95.632	MURS transmitter frequencies
95.633	Emission bandwidth
95.635	Unwanted radiation
95.639	Maximum transmitter power
95.649	Power capability
95.651	Crystal control required
95.655	Frequency capability

Subpart J - Multi-Use Radio Service (MURS)

95.1301	Eligibility
95.1303	Authorized locations
95.1305	Station identification
95.1307	Permissible communications
95.1309	Channel use policy
95.1311	Repeater operations and signal boosters prohibited
95.1313	Interconnection prohibited
95.1315	Antenna height restriction
95.1317	Grandfathered MURS Stations

Subpart D - CB Radio Service & Subpart E - Technical Regulations
Portions relevent to MURS

95.401 (CB Rule 1) What are the Citizens Band Radio Services?

(e): The Multi-Use Radio Service (MURS)--a private, two-way, short-distance voice or data communications service for personal or business activities of the general public. The rules for this service are contained in subpart J of this part.

PRSG Comment: The FCC now prohibits image (video and radiofacsimile) communications. The FCC decided that the transmission of images was not compatible with the use of these frequencies for short, "push-to-talk"-type communications. However, the rules fail to provide specific time limits on individual transmissions, and on exchanges of communications between a group of stations.

95.601 Basis and purpose

The Personal Radio Services are the GMRS (General Mobile Radio Service)-subpart A, the Family Radio Service (FRS)-subpart B, the R/C (Radio Control Radio Service)-subpart C, the CB (Citizens Band Radio Service)-subpart D, the Low Power Radio Service (LPRS)-subpart G, the Wireless Medical Telemetry Service (WMTS)-subpart H, the Medical Implants Communication Service (MICS)-subpart I, and the Multi-Use Radio Service (MURS)-subpart J.

95.603 Certification required

(g): Each Multi-Use Radio Service transmitter (a transmitter that operates or is intended to operate in the MURS) must be certificated in accordance with Subpart J of Part 2 of this chapter, Provided however, that those radio units certificated as of [effective date of Order] need not be recertificated.

PRSG Comment: The FCC has abandoned the former Part 90-type certification process (in 90.203) for MURS, and instead now uses one specific and exclusive to MURS. Most aadio models previously permitted for MURS (before implementation of the current rules [November 12, 2002]) will continue to be permissible to use. However, questions remain about exactly which older models are or are not still permissible to use for MURS stations. For instance, unresolved is the definition of "provisions for increasing its transmitter power" contained in 95.649. Some people have argued that it should be permissible to use higher power transmitters that have either been detuned or reprogrammed to transmit at a lower output. We expect the FCC to further clarify the permissibility of using certain older radio models.

95.605 Certification procedures.

Any entity may request certification for its transmitter when the transmitter is used in the GMRS, FRS, R/C, CB, IVDS, LPRS, MURS, or MICS following the procedures in part 2 of this chapter.

95.631 Emission types

(j): A MURS transmitter must transmit only emission types A1D, A2B, A2D, A3E, F2B, F1D, F2D, F3E, G3E. Emission types A3E, F3E and G3E include selective calling or tone-operated squelch tones to establish or continue voice communications. MURS transmitters are prohibited from transmitting in the continuous carrier mode.

PRSG Comment: The FCC now authorizes only certain specific modes, and specifically prohibits image transmissions. The rules also prohibit continuous transmissions, although the FCC has so far declined to set specific transmitter time limits, or otherwise to define what is "continuous." (We expect further clarifications on this.) The FCC has "grandfathered" prior licensed use of MURS. In the MO&O/SR&O, the FCC indicated that it would exempt all grandfathered MURS users from compliance with the current prohibition of continuous transmissions, but only in conformance with their last Part 90 authorization and any waiver grants (although waivers for continuous transmissions were not required on any of the now-MURS frequencies except on 154.600 MHz).

95.632 MURS transmitter frequencies

(a): The MURS transmitter channel frequencies are 151.820 MHz, 151.880 MHz, 151.940 MHz, 154.570 MHz, 154.600 MHz.
(b): The authorized bandwidth is 11.25 kHz on frequencies 151.820 MHz, 151.880 MHz and 151.940 MHz. The authorized bandwidth is 20.0 kHz on frequencies 154.570 and 154.600 MHz.
(c): MURS transmitters must maintain a frequency stability of 5.0 ppm, or 2.0 ppm if designed to operate with a 6.25 kHz bandwidth.

PRSG Comment: The use of conventional NBFM ("narrowband FM") transmitters, those having a maximum deviation of +/- 5 KHz, is again permissible on the two MURS 154 MHz frequencies. On the three MURS 151 MHz frequencies, only the narrower deviation (+/- 2.5 KHz) is now permitted. As manufacturers produce more "consumer-grade" radios for MURS, the new MURS-specific models will likely employ the more restricted deviation limits and channel bandwidths on both the MURS 151 MHz frequencies (where they are required) and on the 154 MHz ones (where they are permitted but not required). This would allow for a less expensive design and construction, but may result in the transmissions of new, consumer-grade radios sounding "weaker" when received on older NBFM radios monitoring the 154 MHz frequencies.

95.633 Emission bandwidth

(f): The authorized bandwidth for any emission type transmitted by a MURS transmitter is specified as follows:

(1)
Emissions on frequencies 151.820 MHz, 151.880 MHz, and 151.940 MHz are limited to 11.25 kHz.

(2)
Emissions on frequencies 154.570 and 154.600 MHz are limited to 20.0 kHz.

(3)
Provided, however, that all A3E emissions are limited to 8 kHz.

PRSG Comment: See the discussion of the prior rule section. Although the rules permit the use of A3E emissions, this type is rarely used.

95.635 Unwanted radiation

(e)

For transmitters designed to operate in the MURS, transmitters shall comply with the following:

Frequency	Mask with audio low pass filter	Mask without audio low pass filter
151.820 MHz 151.880 MHz 151.940 MHz	(1)	(1)
154.570 MHz 154.600 MHz	(2)	(3)

(1)
Emission Mask 1 -- For transmitters designed to operate with a 12.5 kHz channel bandwidth, any emission must be attenuated below the power (P) of the highest emission contained within the authorized bandwidth as follows:

(i)
On any frequency from the center of the authorized bandwidth f(o) to 5.625 kHz removed from f(o): Zero dB.

(ii)
On any frequency removed from the center of the authorized bandwidth by a displacement frequency (f(d) in kHz) of more than 5.625 kHz but no more than 12.5 kHz: at least 7.27(f(d) -2.88 kHz) dB.

(iii)
On any frequency removed from the center of the authorized bandwidth by a displacement frequency (f(d) in kHz) of more than 12.5 kHz: at least 50 + 10 log (P) dB or 70 dB, whichever is the lesser attenuation.

(2)
Emission Mask 2 -- For transmitters designed to operate with a 25 kHz channel bandwidth that are equipped with an audio low-pass filter, the power of any emission must be below the unmodulated carrier power (P) as follows:

(i)
On any frequency removed from the assigned frequency by more than 50 percent, but not more than 100 percent of the authorized bandwidth: at least 25 dB.

(ii)
On any frequency removed from the assigned frequency by more than 100 percent, but not more than 250 percent of the authorized bandwidth: at least 35 dB.

(iii)
On any frequency removed from the assigned frequency by more than 250 percent of the authorized bandwidth: at least 43 + 10 log (P) dB.

(3)
Emission Mask 3 -- For transmitters designed to operate with a 25 kHz channel bandwidth that are not equipped with an audio low-pass filter, the power of any emission must be attenuated below the unmodulated carrier output power (P) as follows:

(i)
On any frequency removed from the center of the authorized bandwidth by a displacement frequency (f(d) in kHz) of more than 5 kHz, but not more than 10 kHz: at least 83 log (f(d)/5) dB.

(ii)
On any frequency removed from the center of the authorized bandwidth by a displacement frequency (f(d) in kHz) of more than 10 kHz, but not more than 250 percent of the authorized bandwidth: at least 29 log (f(d)(squared) /11) dB or 50 dB, whichever is the lesser attenuation.

(iii)
On any frequency removed from the center of the authorized bandwidth by more than 250 percent of the authorized bandwidth: at least 43 + 10 log (P) dB.

PRSG Comment: Some of the strictly low-level ASCII text above does not fully convey the mathematical formulas actually presented in the rules.

95.639 Maximum transmitter power

(h): No MURS unit, under any condition of modulation, shall exceed 2 Watts transmitter power output.

PRSG Comment: The rules now specify the maximum transmitter power output (TPO). The rules formerly established an ERP (Effective Radiated Power) limit, which was dependent on antenna and antenna line considerations.

95.649 Power capability

No CB, R/C, LPRS, FRS, MICS, MURS or WMTS unit shall incorporate provisions for increasing its transmitter power to any level in excess of the limits specified in 95.639.

PRSG Comment: There remain questions about how the FCC interprets "provisions for increasing its transmitter power." Many otherwise MURS-compliant transmitters are capable of being tuned or programmed for a transmitter power output (TPO) in excess of 2 Watts. Some people argue that if the user does not have access to any external controls or adjustments for increasing the power, then station should be compliant. We expect the FCC to further clarify this issue.

95.651 Crystal control required

All transmitters used in the Personal Radio Services must be crystal controlled, except an R/C station that transmits in the 26-27 MHz frequency band, a FRS unit, a LPRS unit, a MURS unit, a MICS transmitter, or a WMTS unit.

95.655 Frequency capability

(d): No transmitter will be certificated for use in MURS if it is equipped with a frequency capability not listed in paragraph 95.632.

PRSG Comment: This restriction applies only to transceivers first certificated for MURS use after November 12, 2002. Radios certificated for MURS use under Part 95 (or for BRS use under Part 90) before that date will continue to be permissible for MURS use, if all other conditions are also met.

Subpart J - Multi-Use Radio Service (MURS)
General Provisions

95.1301 Eligibility

An entity is authorized by rule to operate a MURS transmitter if it is not a foreign government or a representative of a foreign government and if it uses the transmitter in accordance with 95.1309 and otherwise operates in accordance with the rules contained in this subpart. No license will be issued.

PRSG Comment: PRSG has requested (click here to view details) that the FCC reinstitute licensing for those prior Part 90 licensees of these frequencies who are "grandfathered" in MURS with privileges that exceed those permissible under the current rules.

95.1303 Authorized locations

(a): MURS operation is authorized:

(1)
Anywhere CB station operation is permitted under 95.405; and

(2)
Aboard any vessel of the United States, with the permission of the captain, while the vessel is travelling either domestically or in international waters.

(b): MURS operation is not authorized aboard aircraft in flight.
(c): Anyone intending to operate a MURS unit on the islands of Puerto Rico, Desecheo, Mona, Vieques, and Culebra in a manner that could pose an interference threat to the Arecibo Observatory shall notify the Interference Office, Arecibo Observatory, Post Office Box 995, Arecibo, Puerto Rico 00613, in writing or electronically, of the location of the unit. Operators may wish to consult interference guidelines, which will be provided by Cornell University. Operators who choose to transmit information electronically should e-mail to: prcz@naic.edu.

(1)
The notification to the Interference Office, Arecibo Observatory shall be made 45 days prior to commencing operation of the unit. The notification shall state the geographical coordinates of the unit.

(2)
After receipt of such notifications, the Commission will allow the Arecibo Observatory a period of 20 days for comments or objections. The operator will be required to make reasonable efforts in order to resolve or mitigate any potential interference problem with the Arecibo Observatory. If the Commission determines that an operator has satisfied its responsibility to make reasonable efforts to protect the Observatory from interference, the unit may be allowed to operate.

95.1305 Station identification

A MURS station is not required to transmit a station identification announcement.

PRSG Comment: PRSG has requested that the FCC reinstitute a callsign identification requirement for those prior Part 90 licensees of these frequencies who are "grandfathered" with privileges that exceed those permissible under the current rules. We feel that this is the only way that MURS users can determine (by looking up such licenses by FCC callsign) if operations that appear to violate current rules are and remain appropriately grandfathered.

95.1307 Permissible communications

(a): MURS stations may transmit voice or data signals as permitted in this subpart.
(b): A MURS station may transmit any emission type listed in paragraph 95.631(j) of this chapter.
(c): MURS frequencies may be used for remote control and telemetering functions. MURS transmitters may not be operated in the continuous carrier transmit mode.
(d): MURS users shall take reasonable precautions to avoid causing harmful interference. This includes monitoring the transmitting frequency for communications in progress and such other measures as may be necessary to minimize the potential for causing interference.

PRSG Comment: The rules prohibit continuous carrier transmissions on MURS frequencies. However, rule section 95.1317 permits "grandfathered" (former Part 90) licensees of the frequencies now allocated to MURS to continue to employ continuous transmissions (which were legal under Part 90, except on 154.600 MHz, where the FCC would have required a waiver) on any of the MURS frequencies on which they were previously licensed. PRSG has requested that the FCC reinstitute a callsign identification requirement for those prior Part 90 licensees of these frequencies who are "grandfathered" with privileges that exceed those permissible under the current rules. This would include any grandfathered licenses that authorized operation on any of the current MURS frequencies that continue to operate with continuous transmissions. Subparagraph (d) establishes the active requirement of pre-transmission monitoring. There is no exemption for grandfathered (former Part 90) licensees. PRSG has requested that the FCC require that all transmitters certificated under the current rules (namely, first certificated on or after November 12, 2002) must be configured so that the station cannot transmit unless any selective-muting or decoding of the associated receiver has first been turned off for a minimum period of time.

95.1309 Channel use policy

(a): The channels authorized to MURS systems by this part are available on a shared basis only and will not be assigned for the exclusive use of any entity.
(b): Those using MURS transmitters must cooperate in the selection and use of channels in order to reduce interference and make the most effective use of authorized facilities. Channels must be selected in an effort to avoid interference to other MURS transmissions.

PRSG Comment: The requirement of subparagraph (a) above also existed under Part 90. "Grandfathered" (former Part 90) licensees have no exemption from this rule.

95.1311 Repeater operations and signal boosters prohibited

MURS stations are prohibited from operating as a repeater station or as a signal booster. This prohibition includes store-and-forward packet operation.

PRSG Comment: This language suffers from several deficiencies that PRSG has requested or will soon request that the FCC address. First: In the public petitions, comments and replies submitted to this docket, the implication may have been that "store-and-forward" operations pertained only to packet operations. "Store-and-forward" operation could actually include any emission mode or message content. Indeed, several store-and-forward voice repeaters operating on single MURS frequencies were legally put into service during the pendency of the petitions. PRSG will request that the FCC prohibit the repeating, whether in real time or in a time-delayed ("store-and-forward") manner, of any MURS transmission. This would require establishing the definition of "repeater" specifically within the MURS rules. (The current definition of "repeater" in the GMRS Rules, at 95.29, establishes that the FCC only considers a GMRS station that retransmits signals simultaneously to be a repeater.) Second: Nowhere in Part 95 has the FCC defined "signal boosters." For instance, does this apply solely to an RF signal amplifier and not to a receiver preamplifier? Does it apply only to transmissions on MURS frequencies, or also to the use of MURS frequencies to transmit to another radio which then retransmits those signals on non-MURS frequencies? The only reference in the MO&O/SR&O, other than in the rule section and title stated above, is in footnote 84 (of paragraph 26 ), which cites a reference to "signal boosters" in Parts 22, 90 and 94, and to WT Docket No. 95-70. In addition, there is an entirely separate kind of "signal booster" function which the FCC needs to address specifically. This is the concept of "a mobile extender" station of the type authorized on some Part 90 frequencies. In this application, a person transmits from a low-power handheld unit to a nearby vehicle, within which there is a repeater-type station which then (usually simultaneously) retransmits that signal through a high-power, vehicular-mounted radio (usually on a non-MURS frequency). This type of operation would seem to fall under both the prohibited repeater-type and prohibited signal-booster-type definitions. The FCC needs to clarify or to modify this language, especially to bring the MURS Rules into conformity with the FCC's stated intent to place all MURS-related requirements into the MURS Rules themselves.

95.1313 Interconnection prohibited

MURS stations are prohibited from interconnection with the public switched network. Interconnection Defined. Connection through automatic or manual means of multi-use radio stations with the facilities of the public switched telephone network to permit the transmission of messages or signals between points in the wireline or radio network of a public telephone company and persons served by multi-use radio stations. Wireline or radio circuits or links furnished by common carriers, which are used by licensees or other authorized persons for transmitter control (including dial-up transmitter control circuits) or as an integral part of an authorized, private, internal system of communication or as an integral part of dispatch point circuits in a multi-use radio station are not considered to be interconnection for purposes of this rule part.

PRSG Comment: This is entirely new language (although, as described in the MO&O/SR&O at paragraph 27 , it does follow the general language of Part 90 in distinguishing public from private networks). It will prohibit the retransmission on MURS frequencies of signals passed over the public switched telephone network. What the new rule language does not directly address is the permissibility of transmitting signals to or from networks other than the public switched telephone network, if those networks themselves are (in turn) interconnected with or share other elements with the public switched telephone network. In today's world of complex networks, there are some networks (such as those supplied by cable television providers, and others; but including any that provide connection with the Internet) that provide services to the public that are essentially identical to those of the public switched network, or that directly interface themselves with the public switched telephone network. Some MURS users have advocated such networked use and interface with MURS stations, suggesting that since the first user connection is not with the PSTN itself, such network interfacing is arguably permissible. Whatever the merits of permitting or prohibiting interconnection with such allegedly "private" networks (whether for voice or data transmissions), the issue of employing MURS stations as a connection point (but especially as a portal of entry or exit) in any network that is publicly accessible (whether or not through the public switched telephone network) will need to be addressed sooner or later. PRSG believes: The sooner, the better. (We raise this issue specifically in our most recent Petition for Reconsideration.

95.1315 Antenna height restriction

The highest point of any MURS antenna must no be more than 18.3 meters (60 feet) above the ground or 6.10 meters (20 feet) above the highest point of the structure on which it is mounted.

PRSG Comment: This is entirely new language, and will limit the height of any antenna that transmits signals on frequencies allocated to MURS. Unresolved is if this language would limit the height of signals received by MURS stations.

95.1317 Grandfathered MURS Stations

Stations that were licensed under Part 90 of the Commission's Rules to operate on MURS frequencies as of November 13, 2000, are granted a license by rule that authorizes continued operations under the terms of such nullified Part 90 authorizations, including any rule waivers.

PRSG Comment: This is entirely new language. It establishes "grandfathering rights" for those operations now on MURS frequencies whose prior Part 90 licenses granted privileges or technical parameters not in compliance with the current MURS rules. This will apply only to operations actually authorized by FCC license, not for those (including the vast majority of operations on these frequencies before creation of MURS and the reallocation of these frequencies to Part 95 from Part 90) that were not licensed, or that were licensed but whose technical parameters violating the current MURS rules had not been authorized by those licenses or by the prior Part 90 rules. In our most recent Petition for Reconsideration , we also request that the FCC reinstitute a licensing requirement for these "grandfathered" operations, and that the FCC further require that parties operating under these grandfathered licenses identify by FCC callsign.