Radio frequency devices: Spread spectrum systems operating in 2.4 GHz band; spectrum sharing and new digital transmission technologies introduction,

[Federal Register: June 12, 2001 (Volume 66, Number 113)]

[Proposed Rules]

[Page 31585-31589]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr12jn01-30]

FEDERAL COMMUNICATIONS COMMISSION

47 CFR Part 15

[ET Docket 99-231; FCC 01-158]

Spread Spectrum Devices

AGENCY: Federal Communications Commission.

ACTION: Proposed rule.

SUMMARY: This document proposes to amend the Commission's rules to improve spectrum sharing by unlicensed devices operating in the 2.4 GHz band (2400--2483.5 MHz), provide for introduction of new digital transmission technologies, and eliminate unnecessary regulations for spread spectrum systems. We take these actions to facilitate the continued development and deployment of new wireless devices for businesses and consumers.

DATES: Comments must be filedon or before August 27, 2001, and reply comments must be filedon or before September 25, 2001.

ADDRESSES: Comments filedthrough the Commission's Electronic Comment Filing System (ECFS) can be sent as an electronic file via the Internet to http://www.fcc.gov/e-file/ecfs.html. Parties who chose to file comments by paper should send comments to the Commission's Secretary, Magalie Roman Salas, Office of the Secretary, Federal Communications Commission, 445 Twelfth Street SW., TW-A325, Washington, DC 20554.

FOR FURTHER INFORMATION CONTACT: Neal McNeil, Office of Engineering and Technology, (202) 418-2408, TTY (202) 418-2989, e-mail: nmcneil@fcc.gov.

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Further Notice of Proposed Rule Making and Order, ET Docket 99-231, FCC 01-158, adopted May 10, 2001 and released May 11, 2001. The full text of this document is available for inspection and copying during regular business hours in the FCC Reference Center (Room CY-A257), 445 12th Street, SW, Washington, DC 20554. The complete text of this document also may be purchased from the Commission's duplication contractor, International Transcription Service, Inc., (202) 857-3800, 1231 20th Street, NW., Washington, DC 20036.

Summary of Further Notice of Proposed Rulemaking and Order

1. The Further Notice of Proposed Rulemaking and Order (``FNPRM'') propose to amend part 15 of the Commission's rules to improve spectrum sharing by unlicensed devices operating in the 2.4 GHz band (2400-- 2483.5 MHz), provide for introduction of new digital transmission technologies, and eliminate unnecessary regulations for spread spectrum systems. Specifically, this FNPRM proposes to revise the rules for frequency hopping spread spectrum systems operating in the 2.4 GHz band to reduce the amount of spectrum that must be used with certain types of operation, and to allow new digital transmission technologies to operate pursuant to the same rules as spread spectrum systems. It also proposes to eliminate the processing gain requirement for direct sequence spread spectrum systems, which will provide manufacturers with increased flexibility and regulatory certainty in the design of their products. We take these actions to facilitate the continued development and deployment of new wireless devices for businesses and consumers.

2. The original Notice of Proposed Rule Making (``NPRM'') 64 FR 38877, July 20, 1999, in this proceeding, which was initiated in response to a request from the Home RF working group, proposed to amend the rules to allow frequency hopping spread spectrum systems operating in the 2.4 GHz band to use hopping channel bandwidths wider than 1 MHz. The NPRM also proposed to adopt a new method for determining compliance with the requirement that direct sequence systems exhibit a minimum of 10 dB processing gain. The First Report and Order (``First R&O'') 65 FR 57557, September 25, 2000, in this proceeding amended the spread spectrum rules to allow frequency hopping spread spectrum transmitters in the 2.4 GHz band to use bandwidths between 1 MHz and 5 MHz at a reduced power output of up to 125 mW. Frequency hopping systems with a bandwidth of up to 1 MHz are required to use at least 75 non- overlapping hopping frequencies. Use of 75 hopping frequencies is generally not feasible for systems having a bandwidth in excess of 1 MHz because the 2.4 GHz band, which covers 2400-2483.5 MHz, provides only 83.5 megahertz of spectrum. Accordingly, the rules were amended to permit systems using a bandwidth greater than 1 MHz but less than or equal to 5 MHz to use as few as 15 non-overlapping channels provided that the total span of hopping channels be at least 75 MHz. Therefore, while a system using 5 MHz hopping channel bandwidths is permitted to use as few as 15 hopping frequencies, one using 3 MHz hopping channel bandwidths must use at least 25 hopping frequencies to comply with the rules.

3. Frequency Hopping Spread Spectrum Systems. Thirteen parties fileda Joint Petition for Clarification, or in the Alternative, Partial Reconsideration (``Joint Petition'') in response to the First R&O requesting that the Commission clarify its rules to specify a minimum of 15 hopping channels for any frequency hopping system operating in the 2.4 GHz that uses adaptive hopping techniques as allowed under 47 CFR 15.247(h) and limits its output power to 125 mW, regardless of hopping channel bandwidth. We propose to amend 47 CFR 15.247 by incorporating the changes proposed in the Joint Petition. Interested parties are invited to comment on the acceptability of this proposal. Commenters are encouraged to include technical analyses that support claims that this change will either improve or degrade sharing of this spectrum. We particularly invite comment as to whether use of adaptive hopping techniques should be mandatory and how we should determine compliance with this requirement when evaluating specific devices for purposes of equipment certification. Commenters are also

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   encouraged to examine alternative operating parameters or conditions that may achieve the same goals. For example, the operating conditions in the Joint Petition would allow a system using 1 MHz bandwidth hopping channels to use as little as 18% of the available spectrum at 2.4 GHz to implement adaptive hopping techniques. Could the Commission realize the goals of the petitioners by requiring that adaptive hopping systems use a minimum of 25% or 50% of the band with a power reduction in relationship to amount of spectrum used? Could even fewer hops be used efficiently and effectively with a corresponding reduction in power? Those commenters who do not agree that the rule changes would be beneficial to operation in the 2.4 GHz band should provide an explanation.

4. Digital Transmission Systems. We observe that new digital transmission technologies have been developed that have spectrum characteristics similar to spread spectrum systems. Indeed, proponents of some of these technologies allege that their systems meet the processing gain requirement of 47 CFR 15.247(e) for direct sequence spread spectrum systems. However, the current rules only provide for specific types of spread spectrum technology and do not provide latitude to permit other types of technologies that have similar spectrum characteristics. We believe that the rules should be modified to permit the operation of these alternative digital technologies. We propose to amend 47 CFR 15.247 to provide for use of spread spectrum or digital technologies. This proposed change would apply for operations in the current spread spectrum bands at 915 MHz, 2.4 GHz and 5.7 GHz. Digital technologies would be required to meet the same technical requirements as spread spectrum systems, as modified in this proceeding. We believe that this proposal will allow more and more diverse products to utilize those bands and thereby increase consumer choice. It would provide the flexibility and certainty needed to promote the introduction of new, non-interfering products into the band, without the need for frequent rule changes to address each specific new technology that may be developed.

5. The rules for part 15 spread spectrum systems limit maximum peak output power to 1 watt. In addition, the rules for direct sequence systems limit peak power spectral density conducted to the antenna to 8 dBm in any 3 kHz band during any time interval of continuous operation. This peak power density limit is intended to control interference by ensuring that the transmitted energy in a direct sequence system is not concentrated in any one portion of the emission bandwidth. In considering the appropriate power limits for digital modulation systems, it appears that the spectrum characteristics of these systems are very similar to the characteristics of direct sequence spread spectrum systems. Accordingly, it appears that digital systems may exhibit no more potential to cause interference to other devices than direct sequence systems. With this in mind, we invite comment on whether digitally modulated systems should be allowed to operate at the same power levels as direct sequence spread spectrum systems, namely 1 watt maximum output power with power spectral density not exceeding 8 dBm in any 3 kHz band. However, we also invite comment as to whether the flexibility we are allowing for digitally modulated systems warrants a reduction in permitted power levels to reduce the likelihood of any adverse impact on other systems operating in this spectrum, similar to the reduced power levels adopted for wide-band frequency hopping systems. If we find it necessary to reduce the allowed power for digitally modulated systems, should we make any changes in the power level adjustments for point-to-point operation in Sec. 15.247(b)(3)?

6. The proposals made herein would more closely align the Sec. 15.247 rules with the U-NII rules. We seek comment on whether the same result would be achieved by amending the U-NII rules to include the 915 MHz and 2.4 GHz bands. The upper limit of the 5.725-5.825 GHz U-NII band would also need to be expanded to 5.850 GHz in order to realign the standards with those presently permitted under Sec. 15.247. We specifically invite comment on any detrimental impact this could have on manufacturers.

7. Direct Sequence Processing Gain. The processing gain requirement was adopted more than ten years ago as a means to ensure that manufacturers would not take advantage of the higher power levels afforded spread spectrum devices by designing systems with wide bandwidths where much of the energy transmitted is not needed for communication. As the spread spectrum industry has matured it is not clear that this requirement continues to be necessary. Manufacturers have an incentive to design their systems to include processing gain in order for their devices to operate properly when located near other radio frequency devices. In addition, it has become increasingly difficult to determine the true processing gain of certain direct sequence spread spectrum systems. We observe that uncertainties about the processing gain requirement can be a significant impediment to the introduction of new technologies. In light of these factors, we are now proposing to eliminate the processing gain requirement for direct sequence spread spectrum systems. We invite comment on this proposal.

   Initial Regulatory Flexibility Analysis

8. As required by Section 603 of the Regulatory Flexibility Act,\1\ the Commission has prepared an Initial Regulatory Flexibility Analysis (IRFA) of the expected significant economic impact on small entities by the policies and rules proposed in this Further Notice of Proposed Rule Making and Order (Further Notice). Written public comments are requested on the IRFA. Comments must be identified as responses to the IRFA and must be filedby the deadlines for comments on the Further Notice of Proposed Rule Making.

   \1\ 5 U.S.C. 603.

   1. Need for and Objectives of the Proposed Rules

9. This Further Notice of Proposed Rulemaking proposes changes that remove unnecessary regulatory barriers to the introduction of new wireless devices using spread spectrum and other digital technologies. The proposals will also improve sharing of the spectrum by wireless devices operating in the 2.4 GHz band (2400-2483.5 MHz). Specifically, the FNPRM proposes to relax the frequency hopping spread spectrum rules in Sec. 15.247 in accordance with a Joint Petition for Clarification, or in the Alternative, Partial Reconsideration filedby thirteen parties.\2\ The proposed changes would permit all frequency hopping systems in the 2.4 GHz band to use as few as fifteen hopping channels instead of the seventy-five hopping channels some systems are now required to use. Systems using the minimum number of channels will be required to employ adaptive hopping techniques in order to avoid transmitting on occupied frequencies.

   \2\ See Joint Petition for Clarification or, in the Alternative, Partial Reconsideration filedOctober 25, 2000 in ET Docket 99-231 on behalf of 3Comm, Apple Computer, Cisco Systems, Dell Computer, IBM, Intel Corporation, Intersil, Lucent Technologies, Microsoft, Nokia Inc., Silicon Wave, Toshiba America Information Systems, and Texas Instruments.

10. The FNPRM seeks comments regarding alternative operating parameters or conditions for frequency

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    hopping systems that may achieve the same goals. For example, the operating conditions in the Joint Petition would allow a system using 1 MHz bandwidth hopping channels to use as little as 18% of the available spectrum at 2.4 GHz to implement adaptive hopping techniques. The FNPRM asks whether the Commission could realize the goals of the petitioners by requiring that adaptive hopping systems use a minimum of 25% or 50% of the band with a power reduction in relationship to amount of spectrum used.

11. The FNPRM also proposes to modify the rules for non-frequency hopping spread spectrum systems in the 915 MHz (902-928 MHz), 2.4 GHz, and 5.7 GHz (5725-5850 MHz) bands to accommodate developing systems that use digital modulation techniques. Systems using digital modulation techniques would be required to meet the same technical requirements as spread spectrum systems, as modified in this proceeding. The Commission believes that this proposal will allow more and more diverse products to utilize those bands and thereby increase consumer choice. It would also provide the flexibility and certainty needed to promote the introduction of new, non-interfering products into the band, without the need for frequent rule changes to address each specific new technology that may be developed. This proposal would more closely align the Sec. 15.247 spread spectrum rules with the Sec. 15.407 U-NII rules. Therefore, we seek comment on whether the same result would be achieved by amending the U-NII rules to include the 915 MHz and 2.4 GHz bands.

12. Finally, the FNPRM proposes to eliminate the processing gain requirement for direct sequence spread spectrum systems. The processing gain requirement was adopted more than ten years ago as a means to ensure that manufacturers would not take advantage of the higher power levels afforded spread spectrum devices by designing systems with wide bandwidths where much of the energy transmitted is not needed for communication. As the spread spectrum industry has matured it is not clear that this requirement continues to be necessary. Manufacturers have an incentive to design their systems to include processing gain in order for their devices to operate properly when located near other radio frequency devices.

    2. Legal Basis

13. The proposed action is taken pursuant to Sections 4(i), 301, 302, 303(e), 303(f), and 303(r) of the Communications Act of 1934, as amended, 47 U.S.C. 154(i), 301, 302, 303(e), 303(f), and 303(r).

    3. Description and Estimate of the Number of Small Entities to Which the Proposed Rules Will Apply

14. The RFA directs agencies to provide a description of, and, where feasible, an estimate of the number of small entities that may be affected by the proposed rules, if adopted.\3\ The Regulatory Flexibility Act defines the term ``small entity'' as having the same meaning as the terms ``small business,'' ``small organization,'' and ``small business concern'' under section 3 of the Small Business Act.\4\ A small business concern in its field of operation; and (3) satisfies any additional criteria established by the SBA.\5\

    \3\ 5 U.S.C. 603(b)(3).

    \4\ Id. 601(3).

    \5\ Id. 632.

15. The Commission has not developed a definition of small entities applicable to unlicensed communications devices manufacturers. Therefore, we will utilize the SBA definition applicable to manufacturers of Radio and Television Broadcasting and Communications Equipment. According to the SBA regulations, unlicensed transmitter manufacturers must have 750 or fewer employees on order to qualify as a small business concern.\6\ Census Bureau data indicates that there are 858 U.S. companies that manufacture radio and television broadcasting and communications equipment, and that 778 of these firms have fewer than 750 employees and would be classified as small entities.\7\ We do not believe this action would have a negative impact on small entities that manufacture unlicensed spread spectrum devices. Indeed, we believe the actions should benefit small entities because it should make available increased business opportunities to small entities. We request comment on these assessments.

    \6\ See 13 CFR 121.201, NAICS Code 334220 (SIC Code 3663). Although SBA now uses the NAICS classifications, instead of SIC, the size standard remains the same.

    \7\ See U.S. Dept. of Commerce, 1992 Census of Transportation, Communications and Utilities (issued May 1995), SIC category 3663 (NAICS Code 334220).

    4. Description of Projected Reporting, Recordkeeping and Other Compliance Requirements

16. Part 15 transmitters are already required to be authorized under the Commission's certification procedure as a prerequisite to marketing and importation. See 47 CFR 15.101, 15.201, 15.305, and 15.405. Additionally, manufacturers of direct sequence spread spectrum systems must submit a determination of system processing gain to the Commission in order to obtain product certification.

17. The proposed regulations will add permissible methods of operation for frequency hopping spread spectrum systems. No new reporting or recordkeeping requirements are proposed for the manufacturers of frequency hopping spread spectrum devices. However, the rules proposed in the Further Notice would eliminate the requirement that manufacturers of direct sequence systems submit evidence of compliance with a minimum processing gain. Therefore, the proposed rules reduce the reporting and recordkeeping burdens placed on all manufacturers, including small entities. None of the proposals would require alteration of any existing products.

    5. Steps Taken To Minimize Significant Economic Impact on Small Entities, and Significant Alternatives Considered

18. The RFA requires an agency to describe any significant alternatives that it has considered in reaching its proposed approach, which may include the following four alternatives: (1) The establishment of differing compliance or reporting requirements or timetables that take into account the resources available to small entities; (2) the clarification, consolidation, or simplification of compliance or reporting requirements under the rule for small entities; (3) the use of performance, rather than design standards; and (4) an exemption from coverage of the rule, or any part thereof, for small entities.

19. At this time, the Commission does not believe the proposals contained in the Further Notice will have a significant economic impact on small entities. The Further Notice does not propose new device design standards. Instead, it relaxes the rules with respect to the types of devices which are allowed to operate pursuant to the spread spectrum regulations. There is no burden of compliance with the proposed changes. Manufacturers may continue to produce devices which comply with the former rules and, if desired, design devices to comply with the new regulations. The proposed rules will apply equally to large and small entities. Therefore, there is no inequitable impact on small entities. Finally, the FNPRM does not recommend a deadline for implementation. We believe that the proposals are relatively simple and do not require a transition period to

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    implement. An entity desiring to take advantage of the relaxed regulations may do so at any time.

20. Unless our views are altered by comments, we find that the proposed rule changes contained in this FNPRM will not present a significant economic burden to small entities. Therefore it is not necessary at this time to propose alternative rules. Notwithstanding our finding, we request comment on alternatives that might minimize the amount of adverse economic impact, if any, on small entities.

    6. Federal Rules That May Duplicate, Overlap, or Conflict With the Proposed Rule

21. None.

22. Pursuant to sections 4(i), 301, 302, 303(e), 303(f), and 303(r) of the Communications Act of 1934, as amended, 47 U.S.C. Sections 154(i), 301, 302, 303(e), 303(f), and 303(r), the Further Notice of Proposed Rule Making is hereby Adopted.

    List of Subjects in 47 CFR Part 15

    Communications equipment.

    Federal Communications Commission. Magalie Roman Salas, Secretary.

    Proposed Rule Changes

    For the reasons discussed in the preamble, the Federal Communications Commission proposes to amend 47 CFR Part 15 as follows:

    PART 15--RADIO FREQUENCY DEVICES

1. The authority citation for part 15 continues to read as follows:

   Authority: 47 U.S.C. 154, 302, 303, 304, 307, 336 and 544A.

2. Amend Sec. 15.247 as follows:

   1. Revise paragraphs (a) introductory text, (a)(1)(ii), (a)(1)(iii), (a)(2), (b)(1), (c) and (d).

   2. Redesignate paragraphs (b)(3) and (b)(4) as paragraphs (b)(4) and (b)(5).

   3. Add a new paragraph (b)(3), and revise new paragraphs (b)(4) and (b)(5).

   4. Remove paragraph (e).

   5. Redesignate paragraphs (f), (g), and (h) as paragraphs (e), (f), and (g).

   6. Revise new paragraphs (e), (f), and (g) (The Note following redesignated paragraph (g) is unchanged.).

   The additions and revisions read as follows:

   Sec. 15.247 Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

   (a) Operation under the provisions of this section is limited to frequency hopping and direct sequence spread spectrum systems and digitally modulated intentional radiators that comply with the following provisions:

   (1) * * *

   (ii) Frequency hopping systems operating in the 5725-5850 MHz band shall use at least 75 hopping frequencies. The maximum 20 dB bandwidth of the hopping channel is 1 MHz. The average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 30 second period.

   (iii) Frequency hopping systems in the 2400-2483.5 MHz band shall use at least 75 non-overlapping channels, except that as few as 15 non- overlapping channels may be used for systems that intelligently modify their hopsets in accordance with paragraph (g) of this section. Hopsets modified in this manner must be re-determined at least once every 30 seconds. The average time of occupancy on any channel shall not be greater than 0.4 seconds within a period of 0.4 seconds multiplied by the number of hopping channels employed.

   (2) Systems using direct sequence spread spectrum and digital modulation techniques may operate in the 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz bands.

   (b) * * *

   (1) For frequency hopping systems in the 2400-2483.5 MHz band employing at least 75 hopping channels, and all frequency hopping systems in the 5725-5850 MHz band: 1 Watt. For all other frequency hopping systems in the 2400-2483.5 band: 0.125 Watt * * * * *

   (3) For systems using digital modulation in the 902-928 MHz, 2400- 2483.5 MHz, and 5725-5780 MHz bands: 1 Watt.

   (4) Except as shown below in this paragraph (b)(4), if transmitting antennas of directional gain greater than 6 dBi are used, the peak output power from the intentional radiator shall be reduced below the stated values in paragraph (b)(3) by the amount in dB that the directional gain of the antenna exceeds 6 dBi.

   (i) Systems operating in the 2400-2483.5 MHz band that are used exclusively for fixed, point-to-point operations may employ transmitting antennas with directional gain greater than 6 dBi provided the maximum peak output power of the intentional radiator is reduced by 1 dB for every 3 dB that the directional gain of the antenna exceeds 6 dBi.

   (ii) Systems operating in the 5725-5850 MHz band that are used exclusively for fixed, point-to-point operations may employ transmitting antennas with directional gain greater than 6 dBi without any corresponding reduction in transmitter peak output power.

   (iii) Fixed, point-to-point operation, as used in paragraphs (b)(4)(i) and (b)(4)(ii) of this section, excludes the use of point-to- multipoint systems, omnidirectional applications, and multiple co- located intentional radiators transmitting the same information. The operator of the spread spectrum intentional radiator or, if the equipment is professionally installed, the installer is responsible for ensuring that the system is used exclusively for fixed, point-to-point operations. The instruction manual furnished with the intentional radiator shall contain language in the installation instructions informing the operator and the installer of this responsibility.

   (5) Systems operating under the provisions of this section shall be operated in a manner that ensures that the public is not exposed to radio frequency energy levels in excess of the Commission's guidelines. See Sec. 1.1307(b)(1) of this chapter.

   (c) In any 100 kHz bandwidth outside the frequency band in which the spread spectrum or digitally modulated intentional radiator is operating, the radio frequency power than is produced by the intentional radiator shall be at least 20 dB below that in the 100 kHz bandwidth within the band that contains the highest level of the desired power, based on either an RF conducted or a radiated measurement. Attenuation below the general limits specified in Sec. 15.209(a) is not required. In addition, radiated emissions which fall in the restricted bands, as defined in Sec. 15.205(a), must also comply with the radiated emission limits specified in Sec. 15.209(a) (see Sec. 15.205(c)).

   (d) For direct sequence spread spectrum and digitally modulated systems, the peak power spectral density conducted from the intentional radiator to the antenna shall not be greater than 8 dBm in any 3 kHz band during any time interval of continuous transmission.

   (e) For the purposes of this section, hybrid systems are those that employ a combination of both frequency hopping and direct sequence or digital modulation techniques. The frequency hopping operation of the hybrid system, with the direct sequence or digital modulation operation turned off, shall have an average time of occupancy on any frequency not to exceed 0.4 seconds within a time period in seconds equal to the number of hopping frequencies employed multiplied by 0.4. The direct sequence or the digital modulation

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   operation of the hybrid system, with the frequency hopping operation turned off, shall comply with the power density requirements of paragraph (d) of this section.

   (f) Frequency hopping systems are not required to employ all available hopping channels during each transmission. However, the system, consisting of both the transmitter and the receiver, must be designed to comply with all of the regulations in this section should the transmitter be presented with a continuous data (or information) stream. In addition, a system employing short transmission bursts must comply with the definition of a frequency hopping system and must distribute its transmissions over the minimum number of hopping channels specified in this section.

   (g) The incorporation of intelligence within a frequency hopping system that permits the system to recognize other users within the spectrum band so that it individually and independently chooses and adapts its hopsets to avoid hopping on occupied channels is permitted. The coordination of frequency hopping systems in any other manner for the express purpose of avoiding the simultaneous occupancy of individual hopping frequencies by multiple transmitters is not permitted. * * * * *

   [FR Doc. 01-14526Filed6-11-01; 8:45 am]

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