Current Uses of the Land Mobile Service

Public Uses

The general public has access to land mobile services by way of fully regulated service providers called common carriers. Common carriers are regulated by the FCC under Part 22 of the FCC Rules, and are subject to tariffs and regulations written by state public utility commissions. However, some common carrier services, such as cellular radio are now part of the Commercial Mobile Radio Service.[EN18] Recent legislation has amended the Communications Act of 1934 so that substantially similar services be treated with "regulatory parity". Other common carriers in the land mobile service include the conventional land mobile telephone system, and radio paging.

Land Mobile Telephone

In the mid 1960's, a mobile telephone system using analog FM, with such features as automatic frequency selection, direct dialing, and full duplex was introduced as the Improved Mobile Telephone System (IMTS). IMTS was designed to emulate the features found in the landline telephone networks. The service was field tested in Harrisburg, Pennsylvania, from 1962-1964, with commercial service offered beginning in 1965.

Conventional land mobile telephone systems have seen limited use since the inception of cellular systems. Many of the original IMTS frequencies are used in rural areas to interconnect to the local telephone service, where cellular service is not yet available.

Cellular Telephone

The concept of cellular radiocommunications was developed by AT&T Bell Laboratories in 1947. It took, however, more than three and a half decades before the first cellular network began operating in October, 1983. As of March 1994, "1,529 cellular systems, employing nearly 40,000 people, [had] been activated in 734 markets across the United States."[EN19]

A cellular system is a mobile, two - way radio telephone system operating in the 824-849 MHz and 869-894 MHz bands that uses controlled, low-powered transmitters and divides the service area into small "cells". The radius of a cell, which ranges from 2 km to 32 km, is partly determined by the transmitter power of the base station, but also by careful use of terrain shielding, reduced antenna height, and directional antennas. Consequently, for a given number of frequencies per cell, the use of smaller cells allows a given frequency to be re-used in other nearby geographic areas, allowing more users to be served by a given set of frequencies.

Cellular telephony has experienced phenomenal growth since its inception in 1983. Public acceptance of cellular has grown at a rate faster than TV, cable TV, VCR's, and facsimile. Even during the recession in 1991, the number of subscribers grew at an annual rate of approximately 43 percent. This growth rate represented an additional 2.3 million new subscribers within a 12-month period. The Cellular Telecommunications Industry Association (CTIA) estimates that 17,000 subscribers are added each day. Cellular growth rate is attributed in part to the unique and appealing operational characteristics of the cellular system—mobility and instant communications. Other factors include the reduced size and decreasing prices of the mobile and portable equipment.

Radio Paging

Radio paging, in existence since the 1950's, is one of the older forms of land-based mobile communications services. It is a one- way calling system operating within the 30 MHz, 150 MHz, 450 MHz and 930 MHz bands, which allows for ubiquitous communications access. It has evolved from the transmission of a simple tone signal or "beep" to its present orientation toward limited transmissions of alphanumeric messages. It is in this context of evolution that the radio paging industry provides various types of services and, consequently, has survived against challenges by newer types of mobile communications.

The rapid growth of the paging services is matched by the growth in retail pager distribution and new service offerings. Despite the recession in 1991, the paging industry sustained a record growth of an additional 1.9 million pagers in service compared to 1.8 million additional pagers in 1990. The U.S. paging industry reached a total of 19 million pagers in service with an estimated service revenue for 1993 of $3 billion. The paging industry experienced a 20 percent annual growth rate from 1990-1992.[EN20]

Private Uses

The private land mobile radio (PLMR) services allow state and local governments, and commercial and non-profit organizations to use the electromagnetic spectrum for mobile and ancillary fixed radiocommunications[EN21] to assure the safety of life and property, and to improve productivity and efficiency. These communications are not intended for general public use. However, recent legislation has amended Section 332 of the Communications Act so that many private land mobile services would be classified as simply "commercial mobile services."[EN22] The rules and regulations governing private radio are contained in Part 90 of the FCC Rules. The FCC has allocated portions of spectrum for the various PLMR services in the following bands: 25-50 MHz, 150-174 MHz, 220-222 MHz, 450-512 MHz, 806-824 MHz and 851-869 MHz (the "800 MHz" band), and 896-901 MHz and 935-940 MHz (the "900 MHz" band). Twenty PLMR services are grouped into broad categories such as public safety, industrial, and land transportation radio services. The different services are assigned different frequencies in accordance with Part 90. Channels are available for either conventional or trunked dispatch operations.

Additionally, Part 90 authorizes one- way paging operations, called private carrier paging (PCP), the Location and Monitoring Service (LMS),[EN23] biomedical telemetry and operations within the specialized mobile radio (SMR) service.

The FCC has allocated spectrum within the 150 MHz, 460 MHz and 929 MHz bands for PCP's. Recently, the FCC agreed to open up PCP eligibility to non-Part 90 users, thus permitting services to individuals.

An SMR system is a radio system in which licensees provide land mobile communications services (other than radiolocation) on a commercial basis to eligible Part 90 entities.[EN24] It is a successful, multimillion dollar industry that has been in existence for two decades. SMR operators provide spectrally efficient, trunked private dispatch communications within the 800 MHz and 900 MHz bands.[EN25] Over 80 percent of the customers who subscribe to SMR services are in the construction, service, and transportation industries. There are over 1.5 million SMR units in operation, with industry sales in 1993 totaling $104 million. Enhanced SMR's (ESMR's) are the next generation of digital systems that provide a greater increase in capacity over the analog systems. These wide-area systems would be treated as commercial mobile systems, and hence, subject to the same "regulatory parity" as cellular systems. Portable biomedical telemetry systems are used primarily to monitor the electrocardiogram of patients recovering from heart attacks. The systems allow ambulatory cardiac patients to move about within a hospital, while nurses monitor their heart functions from a central facility. The data is transmitted by a lightweight monitor, via radio , to a sensitive receiving system with antennas generally installed in the ceilings of the hospital corridors. Medical necessity requires that telemetry transmissions be continuous, real-time, and without any interruption or radio interference. Radio frequency spectrum currently available to support these biomedical telemetry applications includes the 174-216 MHz band on an unprotected, nonlicensed basis under FCC Part 15 Rules, and the 450-470 MHz band on a secondary basis, under FCC Part 90 Rules.

There are over 16 million PLMR transmitters, 12 million of which operate below 800 MHz. Between 1984 and 1991, the number of licensed transmitters grew at an annual rate of 10 percent per year.[EN26]

Federal Uses

A typical Federal non-tactical land mobile radio system uses a wide range of equipment in a variety of geographic environments supporting voice and data communications for non-tactical operations. The range of equipment includes base, repeater, vehicular, and hand-held stations. Federal land mobile radio systems are usually multi-purpose systems; for example, law enforcement, natural resource, medical, administrative, and utility functions may be supported by the same radio system or network. The radio systems, which are purchased from commercial vendors, are similar to those employed by non-Federal entities.

Federal land mobile service operations, other than radio paging, are usually two - way communi- cations between a base and mobile station or between mobile stations. Federal users communicate in a dispatch/supervisory mode (one-to-many) or communicate in a one-to-one mode while other users monitor the channel and take action as appropriate. Typical messages from mobile sources are of relatively short duration. Typical channel hold times for Federal Government mobile communications are quite short, usually less than a minute. Under these circumstances, one or more channels can often be shared by several independent users. Although Federal agencies use common carrier services such as cellular telephones[EN28] and radio pagers to augment communication needs, they do not serve as replacements for the agency's own land mobile systems.

Emerging Uses

Intelligent Transportation System

In the United States, there is growing interest in the development of an automated highway system that will provide for safer and better informed travelers, improved traffic control systems, systems aimed at increasing the efficiency of commercial vehicle and transit operations, and increase national productivity. Advanced technologies will be an integral element of a future transportation infrastructure. Probable configurations will both include mobile data links between vehicles and links between vehicles and the roadside infrastructure for automatic toll collection, route guidance, collision avoidance, etc. ITS is the general term applied to this broad application of modern communications, location, and control technologies to the needs of vehicle transportation. The next five years will see the research and development, evaluation, and operational testing of the following ITS projects and applications:

Traveler Information Systems Traffic Control Systems Route Guidance and Navigation Systems Rural Applications Transit Fleet Management Systems Commercial Vehicle Applications Fare Collection and Smart Cards Commercial Vehicle Network Systems Collision Avoidance Systems Automated Highway Systems[EN44] Transportation Demand Management Systems

The Federal Government involvement in the ITS stems from the Intermodal Surface Transportation Efficiency Act of 1991, which designates the Department of Transportation (DOT) as the lead agency.[EN45] The DOT recently completed a national strategic plan and has initiated efforts to develop a national ITS architecture by 1996.[EN46] In the coming years, the DOT will be working as partners with the Intelligent Transportation Society of America (ITS AMERICA, formerly IVHS AMERICA) and its members to help guide and advance the national ITS program.[EN47]

The DOT, recognizing that the many radiocommunication elements of ITS would be frequency-dependent, developed a radio frequency acquisition strategy for ITS. Its two aims are: first, to obtain specific dedicated frequencies suitable for supporting certain baseline ITS functions on a nationwide basis; and second, to maintain currently available spectrum and identify new opportunities for sharing communications capacity with emerging telecommunications technologies.[EN48]

The ITS will be supported by more than one radio service. Some ITS projects and programs are currently being defined, while other projects are in the testing and evaluation or operational stages. The radio service associated with these projects and programs depends on the use, and could be a combination of the mobile, radiolocation, radionavigation, radionavigation-satellite, fixed, and possibly broadcasting services in the near future. ITS could also employ Part 15 devices and PCS systems. Since most of the ITS systems and user functions are related to the mobile radio service, ITS is included in this chapter.

The Department of Veterans Affairs (VA) stated in its comments that PCS will have a major impact on two - way communications, possibly reducing or eliminating their requirements for conventional two - way radio , cellular, and radio paging systems.[EN61] Other Federal agencies have indicated that PCS may provide only limited spectrum relief or have little impact on land mobile users.[EN62]

The Department of Energy (DOE) has formulated a strategic planning program for its Information Resource Management into the 21st Century called IRM Vision 21. Since radiocommunication services are a critical element of the program, DOE used IRM Vision 21 as a basis for its response to the Inquiry . If DOE projections for the rapid development and deployment of PCS are accurate, PCS will soon be an important element of the mobile radio infrastructure. In particular, DOE offers these predictions for the future of PCS services:

Calculation of Spectrum Requirements

The projected 10-year spectrum requirement is for national (Federal and non-Federal) land mobile services, excluding requirements for special applications such as military tactical and training use. In predicting long-term requirements, various parameters such as the conversion of systems to more efficient ones (called the conversion factor) and the effect of introducing more efficient technologies (called the technology factor) have been assumed for this analysis.

The five main types of land mobile operations: dispatch, non-dispatch, 2 GHz PCS, SMR/ESMR, and other emerging mobile services. Dispatch-type operations include the conventional and trunked land mobile radio systems such as those within the Federal and PLMR services providing primarily voice communications. These services combined have approximately 100 MHz of assignable spectrum for conventional use. Private sector trunking, excluding SMR systems, operates within the 806-824 MHz, 851-869 MHz, 896-901 MHz, and 935-940 MHz bands (19 MHz).[EN90] Although Federal trunking can be established in any band allocated for mobile operations, commercial equipment currently is being used primarily in the 406.1-420 MHz band (14 MHz). Since Federal trunking can be performed in any band allocated for mobile use (unlike the PLMR services that have dedicated trunking bands), this 14 MHz is included in the 100 MHz indicated for conventional use.

Non-dispatch operations include one- way calling systems such as radio paging (5 MHz) and new services such as the 900 MHz advanced messaging services (3 MHz).[EN91] Two - way operations include cellular radiotelephony which has 50 MHz in the 824-849 MHz and 869-894 MHz bands. SMR/ESMR systems operate within portions of the 800 MHz and 900 MHz bands (19 MHz). The emerging 2 GHz PCS includes licensed and unlicensed PCS devices, which total 140 MHz of spectrum.

Other emerging mobile uses include ITS, and advanced private dispatch operations such as transaction/decision processing, facsimile, snapshots, slow and full motion video, and remote file access. The concept of ITS is still evolving, but it is envisioned to provide traffic information over a wide area. The use of two - way telephony and unlicensed PCS may be a component of the ITS concept.

The methodology used to compute the Additional Spectrum Requirement is illustrated in the following discussion for the conventional dispatch operations.

Non-Dispatch Operations

For two - way non-dispatch operations, the current cellular radiotelephone systems are used as a model to formulate a basis for which the end result is derived. As implied by the growth curve in Figure 1-4, it may therefore take 4 times as much spectrum to satisfy the demand for cellular telephone services. Thus, the extrapolated spectrum requirement, assuming today's technology, would show an increase of 150 MHz that would be required so as not to exceed the same level of congestion for cellular-like services. Current digital systems provide a three-to-one increase in capacity. For planning purposes, a nominal three-to-one increase is assumed for this analysis. Therefore, only one-third of the spectrum (or 50 MHz) will be required to support the cellular demands. For the purposes of estimation, it is assumed that 50 percent of cellular systems will convert their current systems to much more spectrum-efficient systems over the 10-year period. Taking this into account, the estimated 10-year additional spectrum requirement is reduced to 33 MHz. One- way calling services include the current paging systems plus other new advanced messaging services such as data messages, fax, voice paging, and wireless E-mail. As implied by the graph in Figure 1-4, it may take three times as much spectrum to satisfy the demand for non-dispatch, one- way services.

Other Land Mobile Services

APCO, in comments to the FCC, stated that public safety services will require an additional 25 MHz by the year 2000, and another 50 MHz by 2010.[EN98] The APCO spectrum requirements are identical to the COPE petition in that 75 MHz was requested for advanced private land mobile applications. We have carefully reviewed these comments and agree that additional spectrum is needed for advanced wireless services such as transaction/decision processing, facsimile, snapshots, slow and full motion video, and remote file access for both public safety and industrial applications. Some of the requested spectrum is included in our assessment of general dispatch and two - way non-dispatch spectrum requirements. Our review indicates that approximately 50 MHz of additional spectrum is required to satisfy requirements for advanced private land mobile applications not previously addressed. It is expected that this 50 MHz would be shared between public safety and industrial uses, with public safety use primarily within urban areas, and industrial use primarily outside of these areas.

A Second Approach to Spectrum Estimation

NTIA requested PCIA to estimate PCS requirements. The PCIA PCS Technical and Engineering Committee derived estimates of clear spectrum required to support PCS services (2 GHz PCS, cellular, ESMR) in the year 2003.[EN99] This report is an update of previous 1992 PCIA reports on spectrum.[EN100]

The methodology employed was a "bottom-up" approach, using estimated traffic loads for the services studied, considering the requirements of voice, data, imagery, and messaging as codified in the market demand research.[EN101] Implementation environments for low, medium, and high geographic densities of cells and population were considered. Included in the calculations were certain assumptions for cell spacing, grade of service, user busy hour traffic statistics, bearer channel bandwidths, and PCS infrastructure buildout. Based on an assumed number of 10 service providers per area, the report concludes that in the year 2003, the required spectrum for the PCS services of cellular, ESMR, and licensed 2 GHz PCS will be between 340 and 399 MHz.

NTIA agrees with the PCIA approach, but believes that urban in-building coverage would most likely be satisfied generally by either wireline or unlicensed wireless systems in the next 10-year period, and that spectrum efficiency is of such importance that cell reuse factors should be no more than seven. Using the PCIA model with a low/medium-density cell infrastructure and a cell reuse factor of seven, the PCIA model yields a spectrum requirement of approximately 216 MHz. This is compared with the NTIA estimation of 230 MHz for similar PCS-type licensed services determined by adding the "current allocated spectrum" and "additional spectrum requirements" column entries for licensed 2 GHz PCS, cellular ( two - way non-dispatch), and SMR/ESMR services.

For paging services, a similar forecast was prepared by PCIA that included four paging applications: one- way , two - way , asymmetrical, two - way symmetrical, and high-speed voice. PCIA concluded that 35 MHz would be required to support these four services.[EN102] NTIA agrees, in general, with the forecasts for the first three paging services mentioned. Comments to our Inquiry did not provide sufficient data to conclude that high-speed voice paging will be a significant service within the 10-year period. Therefore, we cannot concur with the spectrum requirement for high-speed voice paging at this time.

Aeronautical Mobile Service

The aeronautical mobile service is "[a] mobile service between aeronautical stations and aircraft stations, or between aircraft stations, in which survival craft stations may participate."[EN105] The aeronautical mobile service supports voice and data communications between ground stations and aircraft or between aircraft including flight testing, telecommand, airdrome control, and route (R) and off-route (OR) services.[EN106] Many of the communications within this service are used for air traffic services (ATS) and aeronautical operational control (AOC) safety communications.

The aeronautical mobile service, including certain frequency bands and technical standards used for this service, are coordinated internationally through the International Civil Aviation Organization (ICAO) to ensure the worldwide interoperability of these services. Consequently, many of the regulations found in Part 87 of the FCC Rules and the NTIA Manual are based on ICAO standards.

Many aeronautical mobile communications are used by Federal and non-Federal agencies in identical ways and are accommodated in the 2-23 MHz (HF) and 118-137 MHz (VHF) bands. Additionally, the Federal Aviation Administration (FAA) provides air traffic control (ATC) services to military aircraft on allotted frequencies in the 225-400 MHz band.

The HF band includes 21 frequency ranges that are shared equally by Federal and non-Federal users for ATC and AOC functions. These bands, regulated by international agreement, have long provided the major means of communications with aircraft in transoceanic service.[EN107] Because HF signals propagate terrestrially over long distances, HF radio provides most communications with aircraft over ocean routes and in some developing countries. HF is not used over the United States, except in Alaska.

The VHF band provides the primary communications mode for ATS and AOC safety communications for all areas of the world where radio line-of-sight (LOS) services can be established in a practical manner.[EN108] This band is used by civil aviation authorities to provide ATS safety communications and by the airlines, business aviation, and general aviation to provide AOC safety communications. Each communications frequency is re-used as often as possible due to the limited number of available frequencies. The FAA and Aeronautical Radio , Inc. (ARINC)[EN109] maintain an extensive network of VHF radio stations giving reliable coverage over the United States and off-shore areas.