5.226 The frequency 156.525 MHz is the international distress, safety and calling frequency for the maritime mobile VHF radiotelephone service using digital selective calling (DSC). The conditions for the use of this frequency and the band 156.4875-156.5625 MHz are contained in Articles 31 and 52, and in Appendix 18.
The frequency 156.8 MHz is the international distress, safety and calling frequency for the maritime mobile VHF radiotelephone service. The conditions for the use of this frequency and the band 156.7625-156.8375 MHz are contained in Article 31 and Appendix 18.

In the bands 156-156.4875 MHz, 156.5625-156.7625 MHz, 156.8375-157.45 MHz, 160.6-160.975 MHz and 161.475-162.05 MHz, each administration shall give priority to the maritime mobile service on only such frequencies as are assigned to stations of the maritime mobile service by the administration (see Articles 31 and 52, and Appendix 18).
Any use of frequencies in these bands by stations of other services to which they are allocated should be avoided in areas where such use might cause harmful interference to the maritime mobile VHF radiocommunication service.
However, the frequencies 156.8 MHz and 156.525 MHz and the frequency bands in which priority is given to the maritime mobile service may be used for radiocommunications on inland waterways subject to agreement between interested and affected administrations and taking into account current frequency usage and existing agreements. (WRC 07)
US52   In the VHF maritime mobile band (156-162 MHz), the following provisions shall apply:

    (a) Except as provided for below, the use of the bands 161.9625-161.9875 MHz (AIS 1 with center frequency 161.975 MHz) and 162.0125-162.0375 MHz (AIS 2 with center frequency 162.025 MHz) by the maritime mobile and mobile-satellite (Earth-to-space) services is restricted to Automatic Identification Systems (AIS). The use of these bands by the aeronautical mobile (OR) service is restricted to AIS emissions from search and rescue aircraft operations. Frequencies in the AIS 1 band may continue to be used by non-Federal base, fixed, and land mobile stations until March 2, 2024.

    (b) Except as provided for below, the use of the bands 156.7625-156.7875 MHz (AIS 3 with center frequency 156.775 MHz) and 156.8125-156.8375 MHz (AIS 4 with center frequency 156.825 MHz) by the mobile-satellite service (Earth-to-space) is restricted to the reception of long-range AIS broadcast messages from ships (Message 27; see most recent version of Recommendation ITU-R M.1371). The frequencies 156.775 MHz and 156.825 MHz may continue to be used by non-Federal ship and coast stations for navigation-related port operations or ship movement until August 26, 2019.

    (c) The frequency 156.3 MHz may also be used by aircraft stations for the purpose of search and rescue operations and other safety-related communication.

    (d) Federal stations in the maritime mobile service may also be authorized as follows: (1) Vessel traffic services under the control of the U.S. Coast Guard on a simplex basis by coast and ship stations on the frequencies 156.25, 156.55, 156.6 and 156.7 MHz; (2) Inter-ship use of the frequency 156.3 MHz on a simplex basis; (3) Navigational bridge-to-bridge and navigational communications on a simplex basis by coast and ship stations on the frequencies 156.375 and 156.65 MHz; (4) Port operations use on a simplex basis by coast and ship stations on the frequencies 156.6 and 156.7 MHz; (5) Environmental communications on the frequency 156.75 MHz in accordance with the national plan; and (6) Duplex port operations use of the frequencies 157 MHz for ship stations and 161.6 MHz for coast stations.
US266 Non-Federal licensees in the Public Safety Radio Pool holding a valid authorization on June 30, 1958, to operate in the frequency band 156.27-157.45 MHz or on the frequencies 161.85 MHz or 161.91 MHz may, upon proper application, continue to be authorized for such operation, including expansion of existing systems, until such time as harmful interference is caused to the operation of any authorized station other than those licensed in the Public Safety Radio Pool.

Wiki entries

FCC Narrowbanding Mandate

Current Use 150–174 MHz FCC Narrowband Mandate for PLMR and Industrial/Business Radio Pool systems

The FCC has mandated that all Private Land Mobile Radio (PLMR) and Industrial/Business Radio Pool systems operating in the 150-174 and 421-512 MHz bands must operate using a channel bandwidth of no more than 12.5 kHz, or "a technology that achieves the narrowband equivalent of one channel per 12.5 kHz of channel bandwidth (voice) or 4800 bits per second per 6.25 kHz (data) if the bandwidth for transmissions specified in the modification application is greater than 12.5 kHz."

The deadline for narrowbanding is January 1, 2013. Prior to this date, systems in these bands were allowed up to 25 kHz channel bandwidth.

Narrowbanding of the 470-512 MHz portion ("T-band") has been put on hold by the FCC. Congressional action in the Middle Class Tax Relief and Jobs Creation Act mandated that this sub-band be cleared of all mobile systems in light of the TV band incentive auction and the eventual creation of the nationwide public safety broadband network.

History of the Beep

Current Use 152–159 MHz Paging (portions of band)

Cleveland electronics engineer Al Gross invented radio paging in the early 1950s. Gross was a pioneer in portable VHF-UHF devices and an early proponent of “citizens radio,” now called “personal radio” (see 462.5375—462.7375 MHz). He provided paging systems for use in hospitals, though doctors initially resisted the technology.

The basic paging receiver beeps when it receives a distinctive code from a transmitter controlled by a “paging terminal,” connected to the public telephone network. Today’s more sophisticated pagers display the telephone number of the calling party, or alphanumeric messages. The World Wide Web is now the principal data input medium for alphanumeric paging.

Pagers often are used to signal waiting voice mail messages and are increasingly connected to electronic mail services. Voice paging declined in the 1980s, but was supposed to resurge with the advent of digital voice storage in the pager. Considerable investment was made in voice paging in the Narrowband Personal Communications Service (see 901—902 MHz). The reinstituted voice paging services failed to attract enough subscribers, however.

Delighting Guests

Paging also is used to control industrial equipment, to summon animals to feeding, and—in perhaps the most entertaining use we have discovered—to activate fireworks contained in banquet floral decorations.

Today most paging is provided by FCC licensees on a commercial basis. Traditionally, the two types of for-profit paging companies were designated radio common carriers (RCCs), which enjoyed interference-protected service areas and, in some cases, were required to have state utility certification; and Private Carrier Paging (PCP) providers, who operate on channels shared with other such carriers and are supposed to be exempt from state regulation.

Federal budget legislation in 1993 requires similar or comparable treatment, or “regulatory symmetry,” for substantially similar Commercial Mobile Radio Services (CMRS).

CMRS describes radio services offered to the public, or a large segment of the public, for profit and which interconnect to the public telephone network. Many types of CMRS services exist. PCP services were classified as CMRS in 1996. “There are no longer any real differences between private carrier and common carrier paging systems,” according to the FCC.

Nevertheless, the former system continues in that separate regulations govern RCC-based paging in FCC Part 22 rules and PCP-based paging in Part 90. “Not all substantially similar services must have identical technical and operational rules,” the FCC said.

Major Changes

Paging licenses were traditionally granted on a first-come, first-serve basis using careful frequency coordination to avoid interference between systems. The FCC is introducing a new regime into CMRS paging: license auctions in specified geographic areas. Incumbent licensees will retain certain interference protections.

"We noted that if an incumbent already has a significant presence in a geographic area, other potential applicants may choose not to bid for that geographic area," the FCC said. "Thus, market forces, not regulation, would determine participation in competitive bidding for geographic area licenses.

"…Even where only 30 percent of a geographic area is available to a potential new entrant, we do not believe that it has been shown that the new entrant cannot establish a viable system that serves the public as well as the incumbent." The Commission dismissed all mutually exclusive applications for paging licenses filed after July 31, 1996, in preparation for the auction regime (Docket WT 96-18).

In the 929—930 MHz and 931—932 MHz bands, the FCC established paging licenses in Major Economic Areas (MEAs) developed by the Commerce Department and composed of Economic Areas (EAs, see the following).

Special exemptions from auctions apply to certain established paging licensees in the 929—930 MHz and 931—932 MHz bands who earned exclusive licenses through extensive network construction under earlier regulations.

In other, older paging bands, such as 35—36 MHz, 43—44 MHz, 152—159 MHz, and 454—460 MHz, containing small- and medium-sized paging systems, the FCC adopted Economic Areas (EAs), each consisting of metropolitan or similar areas that are centers of economic activity, with surrounding economically related counties.

As is the case with most auctioned licenses, each geographic area licensee is required to provide coverage to specified portions of the population by a certain date. Alternatively, the licensee may demonstrate that it provides "substantial service," that is, "service that is sound, favorable, and substantially above a level of mediocre service." Failure to meet these requirements is supposed to automatically terminate the license.

Incumbents (who did not obtain their licenses in auctions) may make certain changes to their operations, including adding or modifying their transmission sites. To expand their existing radio contours, they must obtain the consent of the geographic licensee for the expansion area, or buy the expansion area at auction even if the area is larger than needed. If the incumbent stops operating, the FCC performs "spectrum reversion," turning the incumbent’s spectrum over to the geographic licensee for that area.

Other services use the 152—159 MHz and 454—460 MHz bands allocated to paging services. These include the Basic Exchange Telecommunications Radio Service (BETRS), which provides rural subscribers with phone service; and pre-cellular two-way mobile telephone services, which operate mostly in the western U.S.

BETRS is licensed under the Rural Radiotelephone Service. Only local exchange telephone companies or companies having state approval to provide local phone service may provide BETRS. By definition, BETRS is a fixed service and is not CMRS.

The Commission decided to include both BETRS and the two-way mobile telephone services on paging channels in its auction scheme, over the protests of rural telephone advocates. However, it will still allow providers to obtain licenses for these services on a secondary, non-interference basis to geographic-area paging licensees.

(Original entry based upon "Wireless Spectrum Finder" by Benn Kobb. Wireless Spectrum Finder is now (c)MMX Technology LLC.)

2019 World Radiocommunication Conference (WRC-19) Agenda Item 1.9

Proposed Use 156–162.05 MHz WRC-19 Agenda Item 1.9.1 156.0125–157.4375 MHz WRC-19 Agenda Item 1.9.2

1.9 to consider, based on the results of ITU-R studies:

1.9.1 regulatory actions within the frequency band 156-162.05 MHz for autonomous maritime radio devices to protect the GMDSS and automatic identifications system (AIS), in accordance with Resolution 362 [COM6/10] (WRC-15);

1.9.2 modifications of the Radio Regulations, including new spectrum allocations to the maritime mobile-satellite service (Earth-to-space and space to-Earth), preferably within the frequency bands 156.0125-157.4375 MHz and 160.6125-162.0375 MHz of Appendix 18, to enable a new VHF data exchange system (VDES) satellite component, while ensuring that this component will not degrade the current terrestrial VDES components, applications specific messages (ASM) and AIS operations and not impose any additional constraints on existing services in these and adjacent frequency bands as stated in recognizing d) and e) of Resolution 360 (Rev.WRC-15);