Broadband Power Line Systems

AGENCY:

Federal Communications Commission.

ACTION:

Proposed rule; notice of inquiry.

SUMMARY:

This document requests comment from the public on the current state of Broadband Power Line (BPL) technology and to determine whether changes to the Commission's rules are necessary to facilitate the deployment of this technology. The Commission believes that BPL could play an important role in providing additional competition in the offering of broadband infrastructure to the American home and consumers because power lines reach virtually every community in the country.

DATES:

Written comments are due on or before August 6, 2003, and reply comments are due on or before September 5, 2003.

ADDRESSES:

Office of the Secretary, Federal Communications Commission, 445 12th Street, SW., Washington, DC 20554. See supplementary information for filing instructions.

FOR FURTHER INFORMATION CONTACT:

Anh T. Wride, Office of Engineering and Technology, (202) 418-0577, TTY (202) 418-2989, e-mail: anh.wride@fcc.gov.

SUPPLEMENTARY INFORMATION:

This is a summary of the Commission's Notice of Inquiry, ET Docket No. 03-104, FCC 03-100, adopted April 23, 2003, and released April 28, 2003. 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 copy contractor, Qualex International, 445 12th Street, SW., Room, CY-B402, Washington, DC 20554. The full text may also be downloaded at: http://www.fcc.gov. To request materials in accessible formats for people with disabilities (Braille, large print, electronic files, audio format), send an e-mail to fcc504@fcc.gov or call the FCC Consumer & Governmental Affairs Bureau at (202) 418-0531 (voice), (202) 418-7365 (TTY).

This is an exempt notice and comment rule making proceeding. Ex parte presentations are permitted, except during any Sunshine Agenda period. See generally 47 CFR 1.1200(a), 1.1203, and 1.1204(b).

Comments may be filed using the Commission's Electronic Comment Filing System (ECFS) or by filing paper copies. See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24,121 (1998). Comments filed through the ECFS can be sent as an electronic file via the Internet at http://www.fcc.gov/e-file/ecfs.html. Generally, only one copy of an electronic submission must be filed. If multiple docket or rulemaking numbers appear in the caption of this proceeding, however, commenters must transmit one electronic copy of the comments to each docket or rulemaking number referenced in the caption. In completing the transmittal screen, commenters should include their full name, Postal Service mailing address, and the applicable docket or rulemaking number. Parties may also submit an electronic comment by Internet e-mail. To get filing instructions for e-mail comments, commenters should send an e-mail to ecfs@fcc.gov, and should include the following words in the body of the message, “get form <your e-mail address>.” A sample form and directions will be sent in reply.

Parties who choose to file by paper must file an original and four copies of each filing. If more than one docket or rulemaking number appears in the caption of this proceeding, commenters must submit two additional copies for each additional docket or rulemaking number. All filings must be sent to the Commission's Secretary, Marlene H. Dortch, Office of the Secretary, Federal Communications Commission, The Portals, 445 Twelfth Street, SW., Washington, DC 20554.

Parties who choose to file by paper should also submit their comments on diskette. These diskettes should be submitted to: Anh Wride, Office of Engineering and Technology, Federal Communications Commission, The Portals, 445 Twelfth Street, SW., Room 7-A125, Washington, DC 20554. Such a submission should be on a 3.5 inch diskette formatted in an IBM compatible format using Word for Windows or compatible software. The diskette should be accompanied by a cover letter and should be submitted in “read only” mode. The diskette should be clearly labeled with the commenter's name, proceeding (including the lead docket number, in this case ET Docket No. 03-104, type of pleading (comment or reply comment), date of submission, and the name of the electronic file on the diskette. The label should also include the following phrase “Disk Copy—Not an Original.” Each diskette should contain only one party's pleadings, preferably in a single electronic file.

Summary of the Notice of Inquiry

1. The Commission seeks to obtain information and technical data on a variety of issues related to Broadband over Power Line (BPL) systems. BPL systems are new types of carrier current system that operate on an unlicensed basis under part 15 of the Commission's rules. BPL systems use existing electrical power lines as a transmission medium to provide high-speed communications capabilities by coupling RF energy onto the power line. Because power lines reach virtually every community in the country, BPL could play an important role in providing additional competition in the offering of broadband infrastructure to the American home and consumers. In addition, BPL could bring the Internet and high-speed broadband access to rural and underserved areas, which often are difficult to serve due to the high costs associated with upgrading existing infrastructure and interconnecting communication nodes with new technologies.

2. The Commission seeks information and technical data so that we may evaluate the current state of BPL technology and determine whether changes to part 15 of the Commission's rules are necessary to facilitate the deployment of this technology. While BPL may be deployed under our existing part 15 rules, the rules do not specifically provide measurement procedures that apply to systems using the power line as a transmission medium. We therefore seek comment on what changes, if any, we should make to our part 15 rules to promote and encourage the new BPL technology and to our measurement procedures for all types of carrier current systems. We further encourage present deployment of BPL that complies with our existing rules, noting that if, or when, our rules are modified, those rules will address prospective compliance.

3. The Commission believes that the introduction of new high-speed BPL technologies warrants a systematic review of the part 15 rules in order to facilitate the deployment of this new technology, promote consistency in the rules and ensure the ongoing protection of the licensed radio services. We first seek to examine the new BPL technology and its various operating environments.

4. Access BPL Systems. Access BPL systems carry high-speed data and voice signals outdoors over the medium voltage line from a point where there is a connection to a telecommunications network. This point of connection may be at a power substation or at an intermediate point between substations, depending on the network topology. Near the distribution point to a residential neighborhood, a coupler or bridge circuit module is installed to enable the transfer of high-frequency digital signals across the low-voltage distribution transformer. Finally, the high-speed communication signals are brought to the home over the exterior service power cable from the bridge across the distribution transformer, either directly, or via an Access BPL adaptor module.

5. Several consortiums have been organized to promote Access BPL and its applications; however, the operating characteristics of Access BPL are not standardized. In order to assist us in understanding the current state of Access BPL, we seek comment and information in response to the following questions:

• What spectrum and bandwidth would Access BPL use? We have granted experimental licenses to some parties under 47 CFR 5 to evaluate Access BPL equipment that operates from 1.7 to 80 MHz. Would Access BPL devices operate in other portions of the spectrum and at what bandwidth?
• Is the spectrum used by Access BPL shared with In-house BPL? Are there any frequency sharing issues to be considered, i.e., should we designate spectrum for Access BPL and In-House BPL? Is spectrum sharing between Access BPL and In-House BPL feasible?
• What data transmission speeds can Access BPL systems achieve? What speeds can be typically sustained under normal user environment conditions? What speeds are envisioned with deployed access shared among several users? Are the speeds symmetric in both the transmit and receive directions?
• What are the modulation techniques? What techniques are used for ensuring the security of data? What schemes are used for contention resolution between Access and various In-House BPL devices, if more than one device needs to take control of the electric wire at the same time to communicate?
• Would Access products work with In-House BPL products and services, without the need for additional equipment, such as converters and adaptors?
• What is the status of development and anticipated timeline for market deployment of Access BPL equipment?
• What standards work has been done domestically and internationally on Access BPL and what are the results of such activities? Are there ongoing international standards activities that would benefit U.S. industry and what steps should the Commission take to encourage this work? We are aware that the IEC CISPR Subcommittee I on Interference Relating To Multimedia Equipment, Working Group 3 on Emission from Information Technology Equipment, is developing conducted emission limits for new BPL technologies. Are there other standards bodies involved in similar activities?

6. In-House BPL Systems. A number of high-speed In-House BPL devices have reached the market within the last few months, operating under our existing part 15 rules for carrier current systems. In-House BPL systems carry data and voice signals between the wiring and electrical outlets inside of a building. In-House BPL systems are aimed at home networking and sharing of resources between devices, such as multiple computers, printers and smart appliances. Each device to be networked is connected to a BPL adaptor module through a Universal Serial Bus (USB) or Ethernet port. The BPL adaptor module plugs into a power outlet and communicates over the electrical wiring with other similar BPL adaptor modules in the home, thus forming a peer-to-peer local area network between these devices. In-House BPL operation may provide Internet sharing or other external service connections independently of Access BPL service.

7. There are several consortiums organized to promote In-House BPL technology and its applications. In-House BPL networking capabilities would encourage the growth of smart appliances and other consumer electronics equipment, facilitating the sharing of resources between various devices and increasing productivity. In order to assist us in understanding the high speed In-House BPL technology, we seek comment in the following areas:

• In-House BPL systems built to the HomePlug standard specifications operate in the frequency range from 4.5 to 21 MHz. Are other In-House BPL devices being designed to operate in other portions of the spectrum, and at what bandwidth?
• What is the highest data transmission speed that In-House BPL systems can achieve? What speeds can be typically sustained under normal user environment conditions?
• What are the modulation techniques? What techniques are used for ensuring the security of data, especially when several residential units share the same common distribution transformer? What schemes are used for contention resolution between various In-House BPL devices, if more than one device needs to take control of the electric wire at the same time to communicate?
• Would products developed according to one standard work with products developed according to another standard, without the need for additional equipment, such as converters and adaptors?
• What standards work has been done domestically and internationally on In-House BPL technology and what are the results of such activities? Are there on-going international standards activities that would benefit U.S. industry and what steps should the Commission take to encourage this work?

8. Interference from BPL Emissions. In both Access and In-House high-speed BPL technologies multiple carriers spread signals over a broad range of frequencies that are used by other services that must be protected from interference. In the spectrum below 30 MHz, incumbent authorized operations include fixed, land mobile, aeronautical mobile, maritime mobile, radiolocation, broadcast radio, amateur radio terrestrial and satellite, and radioastronomy. In the spectrum from 30 to 300 MHz, incumbent authorized operations include fixed land mobile, aeronautical mobile, maritime mobile and mobile satellite, radioastronomy, amateur radio terrestrial and satellite, broadcasts TV and radio. This spectrum is also used for public safety and law enforcement, and Federal government aeronautical radionavigation, radionavigation satellite and radiolocation. Each of these authorized services in the spectrum must be protected from harmful interference.

9. Interference issues may also arise because existing statutes on pole attachment require the co-location of cable and telecommunications equipment from third party service providers on the same utility poles that carry power wires. The close proximity of Access BPL equipment on utility poles may affect (and be affected by) the operation of cable television service and high-speed digital transmission service, such as DSL.

10. We therefore ask for comment and information on the following questions:

• In order to transfer high frequency signals beyond the low-voltage distribution transformer, Access BPL systems use high-pass filter circuits to bypass the transformer and its inherent low-bandwidth characteristics. What is the effect of these high-pass filters with respect to high-frequency signals used inside the house, e.g., from In-House BPL equipment or other in-premises technologies, that may rely on the low-voltage transformer as a natural barrier to avoid causing interference at higher frequencies?
• For Access BPL systems, several methods of RF signal injection onto the medium voltage lines can be envisioned:
• An RF voltage could be applied between a power line and ground;
• An RF voltage could be applied differentially between two phases of a power line; or
• A single power line wire could be driven as if it were a dipole antenna—e.g., by inductively coupling RF energy to it.

11. Other approaches may also be possible. What methods are being considered for signal injection onto the medium voltage lines? What are the implications on radiated emissions of various methods for injecting signals onto the medium voltage lines (e.g., differences in directional characteristics and magnitudes of the emitted fields)?

• Is there a need to define frequency bands that must be avoided in order to protect the licensed users on the same frequencies as those used by Access BPL systems? Are there mitigation techniques Access BPL systems can use to avoid possible interference with licensed users of the spectrum, such as mobile users or public safety and law enforcement users who may be traveling directly beneath the medium voltage lines?
• Since Access BPL equipment is installed on medium voltage lines that supply electricity to a residential neighborhood, should this equipment be treated as operating in a residential (Class B) or commercial (Class A) environment?
• How does the close proximity of Access BPL equipment to cable television and telecommunications equipment from third party service providers co-located on the same utility pole affect the operation of these services? On the other hand, what is the effect of this close proximity to Access BPL operations?
• High-speed In-House BPL systems are being deployed in residences with a telecommunications access connection from a DSL or cable modem service. What mitigation techniques are used by In-House BPL systems to avoid possible interference from DSL or cable modem within the same spectrum? On the other hand, what is the effect of DSL or cable modem on In-House BPL operations?
• What mitigation techniques are used by In-House BPL systems to avoid possible interference with licensed radio services, such as amateur radio, fixed, mobile and broadcast services? Is there a need to define frequency bands that must be avoided in order to protect the licensed services that use the same frequencies as In-House BPL systems?
• What are the probable interference environments and propagation patterns of Access BPL and In-House BPL systems? Are there specific issues of interference that we should address, e.g., an increase in the level of the noise floor? What models are available for predicting radiated emissions from access BPL systems?
• Are there test results from field trials of Access BPL that may assist in the analysis of harmful interference? Inasmuch as In-House BPL equipment is already on the market, are there any reports that may assist in the further analysis of harmful interference?
• Are the existing part 15 rules for low speed carrier current systems adequate to protect authorized users of the spectrum who may be affected by the new high speed BPL technology? What changes to these rules, if any, are necessary to protect authorized radio services?
• How should the part 15 rules be tailored both to ensure protection against harmful interference to radio services and to avoid adversely impacting the development and deployment of this nascent technology?
• Given their different operating environment, is it necessary to tailor the rules to differentiate equipment used specifically in Access BPL and In-House BPL applications, or should one set of general limits be applied to both? What should such limits be and what is the technical basis for them?
• Is there need to specify different limits for Access and In-House systems? For example, would it be appropriate to allow higher emissions for In-House systems where the user would be the principal party affected by interference, and could take steps to mitigate the interference, than for Access systems where the interference would affect a wider area and therefore be more problematic to mitigate? Would higher emissions for In-House systems result in any interference effects in other houses or apartments sharing the same local low voltage distribution by the RF signal being distributed on the low voltage side of the transformer? What limits should be specified, given the above considerations?
• Should the part 15 rules specify both radiated emission limits and conducted emission limits for BPL systems, or would one type of limits be sufficient to control interference from both low speed and high speed BPL? Since all carrier current systems inject RF signals into the power line for communication purposes, would conducted emission limits be more appropriate to protect authorized radio services?

12. Measurement methods. We seek comment on measurement methods for all types of carrier current systems, including new high-speed Access and In-House BPL devices. Because existing carrier current systems use the power line wiring inside a building to transfer information and data, the radiated emissions from RF energy conducted onto the power lines tend to vary from location to location, based on the installation's AC wiring and the loading placed on that wiring. In effect, since the installation's wiring functions as an antenna, that wiring becomes part of the system to be evaluated. As such, measurements to demonstrate compliance with the rules are not normally made at a standard open area test site, because the measurement of each system is unique to its location.

13. Currently, there are no specific test methods in our rules for carrier current systems, rather, measurement procedures have been left to the discretion of the party performing the tests, and thus measurements can be subjective and inconsistent. Furthermore, Access BPL equipment presents unique measurement challenges because it is typically installed on utility poles and operated over medium voltage lines. We therefore request comment and input on the following questions:

• How should the measurement procedures for testing existing low-speed carrier current systems be developed in order to avoid the burden of selecting representative installations and to promote consistency and repeatability of test results? Is it possible to develop a standardized measurement method for testing in a laboratory or at an open area test site using some characterized wiring assembly or artificial impedance network? If so, how?
• How should measurement procedures for testing new BPL systems, both Access and In-House, be developed in order to promote consistency with measurements of existing carrier current systems and repeatability of test results?
• Conducted emissions testing is usually performed using a line impedance stabilization network (LISN), which is an artificial power line network that provides a specified load impedance in a given frequency range. This device is also used to isolate the equipment from the AC supply and to facilitate measurements. If conducted emission limits alone are sufficient to control harmful interference from BPL systems, how should the measurement procedure be specified? How should the characteristics of a line impedance stabilization network be specified for testing both In-House and Access BPL systems?
• Existing literature is inconclusive on the degree of difference in radiated emissions from houses and buildings when In-House PLC signals are injected in common mode (phase/neutral to an RF ground) versus differential mode (phase to neutral). Is there data available that shows radiated emission levels from houses and other buildings, located in the United States, for both types of signal injection? Is the difference sufficiently large as to justify separate conducted limits for common mode and differential mode signals? Alternatively, should a LISN be defined to simultaneously measure the total effect of the common-mode and differential-mode contributions in proportion to their expected respective contributions to radiated emissions? What should be the characteristics of that LISN?
• How should In-House BPL systems be tested for compliance, given that they use the building's wiring as an antenna? The impedance characteristics of in-house wiring changes each time an appliance is turned on or off, which makes modeling this varying impedance a challenging task. Is it possible to develop a standardized measurement method for testing In-House BPL in a laboratory or at an open area test site using a specialized LISN or some characterized wiring assembly? If so, how? Would the same method of measurement be sufficient to test both traditional carrier current system and new high speed In-House BPL?
• How should Access BPL systems be tested for compliance, given that they generally operate in an environment where signals travel on overhead medium voltage lines? Could a standardized measurement method be developed for testing Access BPL in a laboratory or at an open area test site, using a specialized LISN or some characterized pole and wiring assembly? If so, how?
• Are there any international standards that should be investigated for possible adoption in order to facilitate the development of BPL products for a global marketplace?

14. Currently, equipment operating as carrier current systems, such as power line intercom systems, lamp remote controls, low speed power line telephone adaptors, etc. are subject to the Verification procedure under our equipment authorization program. The low speed systems have not been a source of harmful interference to radio communications. In addition, it appears that use of the Verification procedure has been adequate to ensure that such systems comply with the rules. However, the multiple-carrier transmission nature of the new high speed BPL technology could pose increased risk of harmful interference, and thus new BPL devices may need a higher degree of oversight to ensure that authorized users are not subject to interference. Accordingly, we seek comment on the following questions:

• Would the new high speed Access and In-House BPL equipment pose a higher risk of interference to licensed radio services than the traditional carrier current systems?
• Unlike In-House BPL equipment, which usually involves multiple units of a standard module working together, Access BPL may involve two or more different types of components to form the complete system (e.g., Access BPL medium voltage coupler, Access BPL adaptor module, etc.). What components of an Access BPL system should be subject to equipment authorization?
• Should the new Access and In-House BPL equipment be required to comply with either the Certification procedure or the Declaration of Conformity under our equipment authorization program, which warrants additional oversight, or should they be covered under our Verification procedure like the traditional carrier current systems?

15. The Commission believe that the new high speed BPL technology could be used to assist the utilities by adding intelligent networking capabilities to the electric grid, allowing various interconnected and network-addressable BPL components to work together in improving efficiency in activities such as energy management, power outage notification and automated meter reading. In order to help us in evaluating the applicability of BPL technology to power line carrier systems, we seek input on the following questions:

• Will the power line carrier systems currently deployed by the utility companies to control and monitor the electrical system be replaced in the future with the new high speed BPL equipment?
• How would the utility companies deploy these new control systems and how would these new systems coexist with the older control systems?
• Should power line carrier systems using BPL technology be subject to the coordination process in the current database maintained by UTC?
• Are any changes needed in the regulations governing power line carrier systems? Should power line carrier systems using BPL technology be subject to the general requirements for Access BPL systems, since the same system may now be carrying broadband signals as well as monitoring and control signals? How could, or should, these functions be separated?
• What interference issues, if any, besides the issues raised under the general BPL interference section, supra, must be addressed with the deployment of high-speed power line carrier systems?

16. Other Matters. The questions raised in this Notice of Inquiry are intended to solicit information to assist the Commission in deciding whether to propose rule changes as a result of the developing BPL technology. We realize that these questions do not necessarily encompass all of the possible issues raised by this technology. Parties therefore may wish to comment on the following additional topics:

• What standardized transport and data link protocols are typically used between a user's personal computer, for example, and the Internet point of presence, over Access BPL systems? For example, is Point-to-Point Protocol (PPP), PPP over Ethernet (PPPoE), Asynchronous Transfer Mode (ATM), or other such lower layer protocols involved?

17. We seek information on the subject of communications over electric power lines from all interested parties to obtain a wide representation of viewpoints. Accordingly, we request comments on any other matters or issues, in addition to those discussed previously, that may be pertinent to BPL technology.