In the Matter of
AMENDMENT OF PARTS 89, 91, 93, AND 95 (FORMERLY 10, 11, 16, AND 19) OF THE COMMISSION'S RULES TO REDUCE
THE SEPARATION BETWEEN THE ASSIGNABLE FREQUENCIES
IN THE 450-470-Mc/s BAND, AMENDMENT OF PARTS 2, 87 (FORMERLY 9), 89, 91, 93, 95, AND 21 OF THE
COMMISSION'S RULES TO REALLOCATE FREQUENCIES IN THE
460-470-Mc/s BAND AND TO MAKE ADDITIONAL FREQUENCIES AVAILABLE FOR ASSIGNMENT IN THE 450-470-Mc/s
BAND, AMENDMENT OF PARTS 89, 91, AND 93 OF THE
COMMISSION'S RULES TO PROHIBIT THE USE OF FREQUENCIES IN THE 450-470-Mc/s BAND
BY FIXED STATIONS OTHER THAN CONTROL STATIONS USED FOR THE SECONDARY CONTROL OF MOBILE RELAY STATIONS
Docket No. 13847
FIRST REPORT AND ORDER
5 F.C.C.2d 779 (1966), 8 Rad.
Reg. 2d (P & F) 1629 (1966)
RELEASE NUMBER: FCC 66-1084
(November 30, 1966 Adopted)
BY THE COMMISSION: COMMISSIONERS BARTLEY AND WADSWORTH ABSENT; COMMISSIONER
JOHNSON CONCURRING IN PART AND DISSENTING IN PART AND ISSUING A STATEMENT.
1. On November 14, 1960, the Commission issued a notice of
proposed rulemaking in this proceeding which was published in the Federal
Register on November 18, 1960 (25 F.R. 11010). In that notice, the Commission
proposed to amend its rules governing the Public Safety, Industrial, Land
Transportation, and Citizens Radio Services to require reduction in the
modulation frequency deviation of all frequency modulated transmitters operated
in the 450-470-Mc/s band (except class B Citizens stations) from 15 kc/s to 5
kc/s; to reduce the emission bandwidth to 20 kc/s; to reduce the separation
between assignable frequencies from 50 kc/s to 25 kc/s; to make the additional
frequencies thus derived in the 450-460-Mc/s band available for assignment in
the same services; to create two new services, i.e., the Aviation Terminal
Radio Service and the Industrial Protection Radio Service; to reallocate
certain portions of the 460- 470-Mc/s band, including the additional
frequencies made available for assignment; and to prohibit the use of
frequencies in the 450-470-Mc/s band by fixed stations (with certain
exceptions) and certain other proposals.
2. More than 75 comments and reply comments were filed in this
docket. In addition, there are pending petitions for severance and several
petitions for reconsideration filed on other proceedings which we have said
would be considered in the context of this proceeding. The information and
comments filed are nearly 6 years old, conditions have changed, and some of the
issues raised in this docket are being considered by the Land Mobile Advisory
Committee (LMAC).However, we have obtained up-to-date information on the
question of splitting channels in the 450-470-Mc/s band and we have a
reasonably good picture concerning the requirements of the industrial
protection industry and the aviation industry for land mobile communications.
Thus, these matters can be disposed of now. The remaining issues will be considered
and possibly disposed of in the near future.
3. Most of those who filed comments on our proposal to split the
channels contended that the state of the art had not been advanced to the point
where operations with 25-kc/s spacing in the 450-470-Mc/s band were possible.
The land mobile section of the Electronic Industry Association (EIA) in a
detailed study showed that the equipment then available could easily be adapted
to a 5- kc/s deviation, but that the currently required 0.0005 percent tolerances
under normal operating conditions could result in excessive degradation of the
system because of drifts and impulse noise. EIA claimed that in order to
realize the full benefit of 25-kc/s spacing in this band, and to avoid
undesirable degradation, frequency stabilities in the order of 0.0002 percent
were required, but that equipment with such tolerance was not commercially
available.
4. When this proceeding was initiated, nearly 6 years ago, the
450-470- Mc/s band was not heavily used. It is still the remaining major region
of the spectrum allocated to the land mobile services where the expansion of
existing services and new services can now be accommodated. Our purpose was to
provide a technical framework for the fuller utilization of this frequency spectrum.
We had anticipated difficulties in the full implementation of the proposed
technical standards, but our proposal was looking more toward the future and to
anticipated technological developments rather than the situation then
obtaining. Since then, the land mobile service has grown considerably and its
needs for additional frequency space is of major concern to the Commission. It
is clear that we must provide for the fuller utilization of this frequency
space now. The information that has come to our attention in the last 2 years
indicates clearly that splitting the channels in the 450-470-Mc/s band is now
feasible. Also, it is clear that equipment capable of tighter tolerances than
those proposed has been developed and is commercially available.
5. Field tests have been conducted under developmental grants by
the airline industry and by the Land Mobile Advisory Committee and have shown
that adequate communications can be conducted with 25-kc/s spacing in this
band. For example, an ad hoc committee, known as Working Group 8 of the
Technical Standing Committee, formed under the auspices of the Land Mobile
Advisory Committee (LMAC), conducted field demonstrations in the area of New
Orleans, La., in June of 1966. Based on those tests, and on laboratory
experiments, this group concluded that with good frequency maintenance, split
channel operation in the 450-470-Mc/s band by means of reduced deviation,
increased effectiveness of audio rolloff filters and narrow frequency tolerance
for base transmitters, can provide communications of almost the same quality
and service range as are now available with 50-kc/s systems under the same
operating conditions. Tests conducted by the airline industry in 1965 indicated
similar results. Working Group 8 of the LMAC, which consisted of
representatives of the major equipment manufacturers, user groups, and
employees of the Commission, submitted the following recommendation to the
executive committee of LMAC.
It is recommended that the channels in the 450-470-Mc/s band be
split on a two-for-one basis, with the following changes from present
specifications:
Channel separation: 25 kc/s.
Modulation: FM, -5-kc/s peak deviation.
Post-limited audio rolloff filter: As required by present FCC
rules, except change the characteristic describing the required attenuation
from 40 log (f/3) to 60 log (f/3), and require attenuation at all audio
frequencies above 20 kc/s to be 50 dB greater than that at 1 kc/s.
Transmitter frequency tolerances:
Nonmobile stations: 0.00025 percent.
Mobile stations: 0.0005 percent.
The executive committee of LMAC has approved these recommendations.
6. The recommended technical standards for deviation, bandwidth,
and channel spacing are the same as those proposed by the Commission. The
recommended tolerances for base and fixed stations and the standards for audio
rolloff filter are not. We agree, however, with Working Group 8 that the
standards it has recommended are required for more reliable operations with
25-kc/s spacing in the 450-470-Mc/s band. Accordingly, these technical
standards are hereby adopted and are incorporated in the pertinent sections of
the rules.
7. We need now set the effective dates by which these standards
are to be met. To insure availability of equipment, the new standards for
bandwidth, tolerance, and rolloff filter will not be required for new systems
until November 1, 1967. Applications for new systems, and for additional base
and mobile facilities in existing systems to be operated on a frequency other
than that of the existing system, filed on or after November 1, 1967, will be
required to meet the new technical standards. All systems, existing or new,
will be required to be operated with deviation reduced to -5 kc/s by June
1, 1967. However, all systems authorized prior to November 1, 1967, will have
until November 1, 1971, to conform to all new technical standards. [FN1] These technical standards and their effective dates will apply to
existing class A stations in the Citizens Radio Service, but not to class B stations
in that service. The changes in the technical standards herein adopted will
necessitate withdrawal of type acceptance as of November 1, 1971, for a number
of transmitter types now listed in the Commission's radio equipment list, part
C. A list of transmitter types so affected will be issued in the near future.
FN1 The foregoing timetable pertains to
the technical standards governing equipment in the 450-470-Mc/s band. If
efficient maximum utilization of that portion of the spectrum should necessitate
that existing licensees conform to a new reallocation of frequencies, the
action taken herein should not be regarded as precluding a future requirement
that licensees conform to the new allocation at a date earlier than that
indicated for the technical standards.
8. The technical standards and their effective dates are
specified in the rules contained in the appendix attached hereto. These rules
have also been changed editorially, for uniformity and to eliminate grandfather
provisions no longer in effect, but no other substantive changes have been
made.
9. The notice in this proceeding proposed to establish two new
radio services, the Industrial Protection Radio Service and the Aviation
Terminal Radio Service. Many comments addressed themselves to these proposals.
We have considered these comments and find considerable merit in the concept of
making frequencies available for such uses. However, we are presently
reexamining the allocation structure in the 450-470-Mc/s band, and, therefore,
the foregoing matter is one which will be dealt within the context of that
reexamination in a subsequent document.
10. In view of the foregoing, It is ordered, Effective January 9,
1967, that parts 89, 91, 93, and 95 of the Commission's rules are amended.
Authority for the amendments is contained in sections 4(i) and 303 of the
Communications Act of 1934, as amended.
FEDERAL COMMUNICATIONS COMMISSION, BEN F. WAPLE, Secretary.