Broadband over power line

Overview

Broadband over power line (BPL) systems (also known as Power Line Communication/or Carrier (PLC) and Power Line Telecommunication (PLT)), use existing electrical power lines as a transmission medium to provide high-speed communications capabilities by coupling radio frequency (RF) energy onto the power line, which is then distributed into the home. BPL is based on PLC technology developed in 1928 by AT&T Bell Telephone Laboratories, and which has been used for internal and low-speed data communication applications since that time by electric utilities.

BPL technology seems to have a high potential to provide ubiquitous broadband access to households and businesses across a country. The fact that electricity is provided on a nationwide basis seemingly gives BPL an advantage. The commercialization of BPL could also be important from a competition perspective, providing a second or third wire to the home in competition with DSL technology and cable modem technology. It also has the potential to be a shared technology, given its use in developing smart grids and monitoring consumption of electric power to share costs. BPL also has unique features such as the possibility of in-home access for broadband from any power socket in the room without the need for additional in-house wiring.

Types of BPL systems

There are two types of BPL systems:

1) In-house BPL, which uses the electrical outlets available within a building to transfer information between computers and other home electronic appliances; and

2) Access BPL systems, which carry high-speed communication signals outdoors over the medium voltage (MV) lines, from a point where there is a connection to the Internet (backhaul point), to neighborhoods, where they are distributed to homes via the low voltage (LV) power lines or Wi-Fi links. Access BPL alleviates the need to build broadband infrastructure to every customer because power lines are installed virtually everywhere in the United States.

With BPL, a user can plug a computer into any electrical outlet in the home or office and instantly have high-speed Internet access. By combining radio, wireless networking, and modems, data can be sent over power lines at speeds between 500 kilobits and 3 megabits per second (equivalent to DSL and cable speeds).

United States

In the United States, BPL systems operate on an unlicensed basis under Part 15 of the FCC's rules. 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 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.

BPL technology could also be used to assist power utilities by adding intelligent networking capabilities to the electric grid, thereby improving efficiency in activities such as energy management, power outage notification and automated meter reading. Furthermore, the electrical wiring in homes and office buildings establishes a physical connection between all electrical devices and power outlets that are located every few feet in most American homes. The high number of access points can be used to provide networking applications within a building, eliminating the need for new or additional wiring to connect networking adaptors, thus allowing consumers to readily take advantage of the technology. In addition, homeland security would be enhanced by creating new facilities to provide redundancy in case of disruption of one or more existing channels of communications.

While BPL has all the features of a promising technology, it has not, as yet, fulfilled earlier expectations. The extremely slow growth in the number of BPL service providers, and customer base, and the fact that a number of BPL service providers have been withdrawing from the market concentrating instead on developing smart-grid technology to monitor energy consumption, seems to indicate that service providers face problems.

There are a number of technological and, to a lesser extent, regulatory issues which need to be overcome in order to facilitate the take-off of BPL technology in the market. The electrical grid provides a harsh environment for data transmission, issues regarding radio frequency interference are both technological and regulatory, and international standardization is incomplete. BPL requires investment, in particular where power grids are old, and BPL also requires investment to send data over long distances. Furthermore as broadband over DSL migrates to fiber and cable modem speeds increase as a result of new technology, the competitive environment facing BPL becomes more difficult.

In short, while there may be a potential for BPL to further competition in the broadband market, there is little evidence to indicate that this will take place soon and that it can be counted on to provide a competitive alternative in the near term to xDSL (or fiber to the home) and cable modem technologies. Nevertheless, a technology neutral policy would argue in favor of regulators ensuring that no unnecessary barriers are in place for the eventual commercial diffusion of this technology as well as ensuring that interference with other licensed wireless services is minimized.

FCC Activities

On April 23, 2003, the FCC adopted a Notice of Inquiry (NOI), expressing support for the potential of the BPL technology to enable electric power lines to function as a third wire into the home, and create competition with the copper telephone line and cable television coaxial cable line. The FCC said that BPL service could be offered using BPL modems that comply with existing FCC Rules. However, the FCC also asked for comments on whether changes to its rules were needed, either to remove unnecessary barriers to BPL service or to protect other devices from interference from BPL modems.

The FCC has since adopted rules for broadband over power lines to increase competition and promote broadband service.