mobile stations normally associated with another common carrier base station, including mobile units of Canadian registry. Under specific authorization from the Commission, service may be rendered to stations on board vessels. Authority to provide service to vessels may be granted upon a showing that the rendition of service to vessels will not degrade, by kind or extent of usage, the service which would be available, in the absence of service to vessels, to land vehicles receiving or subsequently requesting such services in the area: Provided, That any authorization to render service to vessels, other than itinerant vessels requiring service in other areas where VHF public coast service is not available, shall automatically terminate at the expiration of 60 days after inauguration of VHF public coast service in the area involved. Applications for authority to communicate with vessels shall be accompanied by a showing of the following:

(1) The total number of land mobile units being served through the base station.

(2) The total number of land mobile units to which it is reasonably expected that such service will be furnished at any time in the next 12 months.

(3) The total number of stations on board vessels initially proposed to be served through the base station.

(4) The total number of stations on board vessels to which it is reasonably expected that such service will be furnished at any time in the next 12 months.

(5) Other public radio facilities available in the area providing service to mobile stations on board vessels.

(6) Such other information as may be deemed pertinent, showing that communication with vessels will not degrade or deny service to land vehicles receiving or requesting land vehicular communication service over the radio facilities of the base station, and that such service to vessels is necessary and desirable.

(c) Applications requesting renewal of authority to render service to vessels shall be accompanied by a current showing of information as required in paragraph (b) of this section.

(d) Mobile stations in this service may not be operated aboard aircraft.

(e) Base stations in this service which are authorized to render one-way signaling service may also render such service to receivers installed aboard vessels and aircraft.

(f) Base stations in this service may communicate with appropriately authorized Rural Subscriber stations in the Rural Radio Service, where the use of wire lines is not practicable or feasible. Authorization for the establishment of a Rural Subscriber station may be granted upon a satisfactory showing that it will not degrade the mobile communication service rendered by the base station and a supplementary showing as set forth in § 21.609. Such showing should be incorporated in the application for construction permit for the fixed point to which communication is to be effected.

(g) The base and mobile station facilities authorized in this service shall not be used in connection with any taxicab operations wherein the licensee is directly or indirectly interested through stock ownership or otherwise.

(h) Pursuant to the provisions of the "Convention Between the United States of America and Canada, Relating to Operation by Citizens of Either Country of Certain Radio Equipment or Stations in the Other Country," United States licensed mobile units in this service which are in Canada may be authorized by the Canadian Government to communicate with or through Canadian licensed common carrier base stations in the land mobile radio service or with base stations licensed under the rules of this part. Canadian licensed mobile units in the common carrier land mobile radio service which are in the United States may communicate with and through United States licensed base stations in this service provided authority for such communication has been granted by the Commission upon proper application therefor. (See § 21.29 (i) and (j).)

(i) Unless otherwise prohibited by agreements, laws, rules, regulations, etc. of the foreign country concerned, base stations in this service are not prohibited from rendering trans-border communication service for hire to mobile units in that country which are properly licensed to operate in the common carrier land mobile service of either country.

(j) Auxiliary test stations in this service shall normally be operated upon mobile station frequencies only for the purpose of determining the performance of fixed receiving equipment remotely located from the base station with which it is associated or where the receiving equipment is located with the base station and both are remote from the control point of the station: Provided, how

ever, That a transmitter used in an auxiliary test station may be used as a standby transmitter upon the frequency of the base station with which it is associated whenever such base station is out of service for maintenance or repair.

(k) A subscriber's dispatch station in this service is authorized to intercommunicate only with the mobile stations of said subscriber through the base station with which it is associated. Where more than one subscriber jointly operate a dispatch station, each subscriber shall communicate only with his own mobile stations.

§ 21.510 Base stations may be authorized only as part of integrated radio system.

Base stations will be authorized only as a part of an integrated communication system wherein mobile units associated therewith are also licensed to the base station licensee (see § 21.15 (i)). § 21.511 Communication service to own

mobile units.

(a) Upon filing an application for renewal of station license for a base station in this service, a miscellaneous common carrier applicant shall submit a factual statement to show that, during the preceding license period, at least an average of 50 percent of the mobile units on any channel to which communication service has been rendered by a base station have been used by persons not directly or indirectly controlling or controlled by, or under direct or indirect common control with the applicant. If an applicant is unable to meet such criterion, he shall show what efforts have been made to achieve use of the service by the public and offer such further showing or explanation as he may deem appropriate.

(b) Wire-line communication common carriers may be authorized to establish land mobile radio facilities under this part of the rules for the purpose of providing communication facilities for their own use incident to construction and maintenance of public communication facilities: Provided however, That the use of the authorized facilities on such frequencies shall be on a secondary basis and subject to use by public subscribers at any time when required for the rendition of public communication service.

§ 21.512 Priorities for service to subscribers.

(a) Subscriptions to mobile telephone service shall be afforded in the following order of precedence and in chronological order of filing of request for service within each of the following customer categories:

(1) Category 1: Public safety and health. Official federal, state, county and municipal government agencies protecting the public safety and health; private organizations and persons engaged primarily in protecting the public safety and health such as physicians, hospitals, ambulance services, volunteer fire departments, American Red Cross, licensed protective patrols and armored cars and similar agencies.

(2) Category 2: Public service. Contract carriers, common carriers, and public utilities (exclusive of taxicab and livery service), for communications other than correspondence of the general public.

(3) Category 3: Quasi public service. Emergency repair organizations, not included in Category 1, protecting health and property; press associations, newspapers and broadcasting stations.

(4) Category 4: Physically handicapped. Persons who because of physical handicaps, operate specifically equipped vehicles and are unable to leave such vehicles without assistance.

(5) Category 5: Industrial. Gas or oil producing or drilling operators; producers and distributors of fuel and lumber and other construction materials and equipment; food processing, distribution and storage organizations; producers of substantial quantities of food; business concerns engaged in construction of housing and industrial or public works; taxicabs and livery service.

(6) Category 6: Traveling public. Trains and watercraft where service is made available to passengers.

(7) Category 7: All others

(b) After initial establishment of service in accordance with the table of priorities in paragraph (a) of this section when facilities in a given area are insufficient to furnish service to all who desire mobile radiotelephone service, applications for new or additional mobile units shall be ranked within the categories in order of date of filing and service shall be afforded such applicants as facilities become available, in descending order of precedence.

§ 21.513 Location of message center. Within the service area encompassed by the field strength contour of each base station as defined in § 21.504, there shall be at least one message center so located that the major portion of subscribers' local exchange landline telephone calls, which originate or terminate in such area in conjunction with messages transmitted or received by said station, cost no more per call than the local message single unit rate. In cases where the control point of a base station is not so located, a public foreign exchange telephone circuit shall be provided to afford service so that a radio service subscriber may communicate between such points at a cost per call not in excess of the local message single unit rate.

§ 21.514 Responsibility for operational control and maintenance of mobile units.

(a) The licensee of a base station in this service shall be responsible for exercising effective operational control over all mobile units with which it communicates. The proper installation and maintenance of such mobile units shall be the responsibility of the respective licensees thereof.

(b) A mobile unit normally associated with and licensed to a specified base station will be deemed, when communicating with a different base station pursuant to legally effective tariff provisions, to be temporarily associated with and licensed to such different base station and the licensee of such different base station shall, for such temporary period, assume the same licensee responsibility for such mobile unit as if such unit were regularly licensed to it.

§ 21.515

Control points, dispatch points and dispatch stations.

(a) Dispatch stations, other than those installed pursuant to § 21.519 (a), may be installed only with specific authorization from the Commission. Upon removal of a specifically licensed dispatch station, the licensee must within 30 days thereafter submit to the Commission in Washington, D.C., the dispatch station license for cancellation. Dispatch points may be installed or removed without authorization. Dispatch point circuit facilities shall be installed in conformance with the requirements of paragraph (c) (2) of this section.

(b) To insure the maintenance of station control, means shall be provided

whereby each dispatch station and each dispatch point is maintained under continuous effective operational supervision of one or more control points.

(c) At each control point for a base station or fixed station in this service, the following facilities will be installed:

(1) Equipment to permit the responsible radio operator to monitor aurally, at such intervals as may be necessary to insure proper operation of the integrated communication system, all transmissions originating at dispatch points under his supervision and at stations with which the base station communicates.

(2) Facilities which will permit the responsible radio operator either to disconnect immediately the dispatch point circuits from the transmitter or immediately to render the transmitter inoperative from any dispatch point associated therewith.

NOTE: Reference should be made to §§ 21.118 and 21.518 for additional control point requirements and also to § 21.205 concerning operator requirements.

[28 F.R. 13002, Dec. 5, 1963, as amended at 29 F.R. 11362, Aug. 6, 1964]

§ 21.516

Additional showing required with application for assignment of additional channel.

An application requesting the assignment of an additional channel at an existing Domestic Public Land Mobile radio station (other than control, dispatch or repeater), in addition to the information required by other sections of the rules, shall include a showing of the following:

(a) The number of mobile units for which orders for service are being held.

(b) Data showing the actual traffic loading on each channel assignment of the present radio system during the busiest 12 hour periods on three days (within a seven day period) having normal message traffic not more than 30 days prior to the date of filing. This information should be reported separately for each of the three days selected, which should be identified by dates, and should disclose the following:

(1) The number of mobile units using the service during each of the days specified.

(2) The number of calls completed each hour.

(3) For systems that provide message relay service, (i) the number of calls held, (ii) the total holding time, and (iii) the maximum holding time for a

call, due to busy radio circuit conditions during each hour; or, for systems that do not provide message relay service, the total number of minutes that the channel (base and mobile) was utilized for transmissions between the base station and land mobile units during each hour. [30 F.R. 2448, Feb. 25, 1965]

§ 21.517 Use of base station as a repeater station.

On its regularly assigned frequency, a base station may be used to perform the added functions of a repeater station when means are provided whereby the licensee of the radio system is able to turn the base station on and off at will from its control point irrespective of the transmissions of subscriber units on the mobile station frequency associated therewith.

§ 21.518 Use of mobile station frequency for control station.

Upon proper application to the Commission for a construction permit to install a control station, a base station applicant or licensee may be authorized to operate its base station via a control station using the mobile station frequency paired therewith. In order to ensure retention of essential operational control of the radio system by its licensee, it is expected that this method of operation will not be installed where the signals from subscriber operated units are able to override the functions of the control path between the control and base station, or where such operation will cause harmful interference to another radio system. The control station shall be provided with coded signals whose transmission will enable the control station to shut down and reactivate the base station at will, irrespective of the transmissions of subscriber units associated therewith. Additional coded signals may be employed by the control station for selective signaling of subscriber units or for performing essential functions at the base station, e. g. controlling aeronautical obstruction marking lights on the base station antenna tower. The coded signals used by control stations for shut down and reactivation of the base station, or for any other essential control functions (other than selective signaling incidental to establishment of subscriber communications) connected therewith, shall consist of two or more sequentially transmitted tones whose

combined duration shall not exceed one second. Use of tone modulation for selective signaling to and from subscriber radio installations is not required; however, when tone modulation is used for this purpose, the aforementioned limitation on the combined duration of tones is not applicable. Radio installations in the premises of, or in vehicles of, subscribers are not permitted to be equipped with code signaling devices (other than for signaling incidental to establishment of subscriber communications) whereby the user would be able to reactivate the base station after the radio system has been shut down by the licensee. Applications for authority to operate a control station upon the mobile station frequency shall be supported by complete engineering information disclosing, among other things, all particulars of the code signaling system which is to be employed.

§ 21.519 Use of mobile station frequency for dispatch stations.

Au

A base station licensee may be authorized to install, for a mobile station subscriber or a group of mobile station subscribers, a dispatch station using the mobile station frequency paired with the associated base station frequency. thorization for the establishment and operation of any dispatch station will be on the express condition that such station will not cause harmful interference to the mobile or rural radio services and will not inhibit use by the mobile radio service of the frequencies assigned to the dispatch station or degrade the mobile communication service rendered by the base station. No dispatch station shall be installed at any site or under conditions whereby it will be capable of overriding the control functions of a control station using the same frequency.

(a) A licensee may install a dispatch station without authorization for the specific location if the antenna height employed at any such location does not exceed the criteria set forth in § 17.3 of this chapter, the rated power output of the transmitter does not exceed 10 watts and each such installation otherwise complies with the requirements of §§ 21.107, 21.108, 21.110, 21.506, 21.520 and all other pertinent provisions of this part. The number of such dispatch station installations shall not exceed the number stated on the base station license. The operation of any such installation

shall be subject to termination by the Commission without a hearing upon notice to the licensee.

(b) Any proposal for the installation of a dispatch station which does not comply with the limitations and requirements of paragraph (a) of this section shall be submitted to the Commission, upon proper application (FCC Form 401) for a construction permit.

[29 F.R. 11362, Aug. 6, 1964]

§ 21.520 Notification of operation of dispatch station without specific authorization.

(a) The licensee of a base station who proposes to establish a dispatch station pursuant to the provisions of § 21.519 (a) shall notify the Commission at Washington, D.C., 20554, and its Engineer in Charge of the radio district wherein operation is to be conducted, at least 2 days prior to the installation of the facilities. This notification shall include:

(1) The name(s) and address(es) of subscriber (s) and the number of mobile stations assigned to each subscriber.

(2) A description of the transmitting location, including the geographic coordinates to the nearest second of latitude and longitude, and also by conventional reference to street number, landmark, etc.

(3) The name of the manufacturer, model number and rated power output of transmitter to be installed.

(4) The transmitting antenna make, model number and power gain in decibels with respect to a reference half-wave dipole antenna.

(5) The overall height, in feet above ground level, of the transmitting antenna.

(6) The location of the transmitter control point.

neer in Charge, at least 2 days prior to the execution of the change.

[29 F.R. 11362, Aug. 6, 1964]

Subpart H-Rural Radio Service § 21.600 Eligibility.

Authorizations for central office stations and interoffice stations will be issued to existing and proposed communication common carriers. Authorizations for rural subscriber stations will be issued to communication common carriers or to individual users of the service. Applications will be granted only in cases where it is shown that (a) the applicant is legally, financially, technically and otherwise qualified to render the proposed service, (b) there are frequencies available to enable the applicant to render a satisfactory service and (c) the public interest, convenience or necessity would be served by a grant thereof.

§ 21.601 Frequencies.

(a) The following frequencies are available primarily to the Domestic Public Land Mobile Radio Service and, on a secondary basis, to stations in the Rural Radio Service, provided no harmful interference is caused to stations in the Domestic Public Land Mobile Radio Service:

(7) The exact frequency or frequencies to be used.

152.571

152.60 1

152.63 1

1 157.83 1 157.86 1 157.89 1157.92 1 157.95

1 157.98