POWER LINE COMMUNICATIONS
The futurists forecast the emergence of an Information Society or Electronic Society in the making
By Yousaf Haroon
The author is Assistant Professor (Management) National Post Graduate Institute of Telecommunications & Informatics (NPGIT&I), PTCL. firstname.lastname@example.org
Sep 15 - 21, 2003
Mr. Yousaf Haroon specializes in Telecommunication Management, Business Competition and Strategy, WTO and GATS, Regulation and Innovative Business Ideas. He has extensively represented at international and national forms. Recently he has been a participant of advance international telecom management course on Telecom Policy from Sweden working on some 25 developing countries telecom policy and telecom market models. National Post Graduate Institute of Telecommunications and Informatics (NPGIT&I) has been the top institute working for human resource competence development in the field of telecom engineering and management initially for PTCL and now endeavors to up-grade its status into the leading Telecom University for the Region.
The single most important industry of the future in undoubtedly is the telecommunication industry providing the 'glue' that holds many of today's human activities ranging from business to government, society to social work, battle ground to space, together. As the use of modern technology is increasing manifolds the impact of telecommunications technology has shifted from centralized to distributed computing infrastructures and from traditional paradigms to client/server paradigm where access to high speed digital networks is becoming the necessity. From electronic government to electronic commerce, the need for more bandwidth has been pushing technology innovation frontiers beyond limits of imagination, where the futurists forecast the emergence of an Information Society or Electronic Society in the making. This means that the whole range of human activities can be digitalized using Information Communication Technology (ICT).
Internet is a reality today. This miracle has given birth to one of the foremost killer application known commonly as IP (Internet Protocol). It is due to the IP-based technologies today that suddenly the whole world of machines have started talking to teach other and they are eaten away by the cloud to become the part of the Internet world using Blue Tooth or Digital Gene.
In short, the world saw how plain old telephone network (POTS) become IP networks. Even more amazing was the phenomenon of use of wire and wireless mediums for data-communication giving birth to convergence in telecom networks into digital data networks over fiber, microwave, infrared, cable and now on power-line communications.
From a technologist or telecom scientist point-of-view imagination is always the source of creativity leading to a possibility of great innovative ideas which the world has never experienced before. But there is also a bitter truth that no greater idea is greater if it is not a good business. Therefore, innovation and creativity has links deep routed into becoming either a great business idea or a paradise lost. Therefore, the critical question today, the world faces is of industry standardization and business potential of the emerging technology. Even greater is the fight over regulation of competition in a specific industry that who regulates what. As telecommunications today become more and more software and data driven, the definition of telecommunication industry running voice channels over physical cables is become blur. Today, there is a greater confusion over broadcasting networks and telecommunication networks. Telecommunication technologists have already discarded the horizontal demarcation to vertical integration of application based industry regulation:
Therefore, the biggest question is not the possibility of technology but of business potential of technology in the competitive market. In telecommunications, the biggest concern is the role of defining legal framework based on economic jurisprudence which can ensure availability of cheaper and better technologies to the masses versus the potential threat of new technologies to the older ones. The paradox is that if the regulator opens the new technologies to enter market the old telecom operators are threatened to obsolescence creating another threat of social disparity in the form of unemployment by death of telecom incumbent operator. If the regulator bars new technologies it disallows access to innovation to the general public who can benefit from cheaper option. In both case it seems the regulator has to face the burnt of a regulatory fiasco as the regulator tries to create a social equinox. Anyhow, old technologies becoming obsolete and new technologies gaining market dominance is the fact of life no matter whatever is the market situation or barriers to entrance may be. This debate is in fact more true for Pakistan as we have seen that entrance of new technologies can be delayed in market launch in commercial terms but one way or the other these are quickly adopted by the consumers.
INTRODUCTION TO POWER LINE COMMUNICATION
Powerline Communication is the technology that enables the transmission of data over power line that carries and supplies electric power. PLC has long history while the concept of broadband data transmission has been recently developed. Replacing the slow data transmission rate with only one-way communication, the emerging PLC technology has brought wider bandwidth with two-way communications. For a long time, PLC technologies have achieved very limited success. The major applications of PLC Technology have remained within the boundaries of monitoring & control of load control, low capacity data communication, various automation system and remote metering system, and low speed data communication up to 9600bps as well as analog signal transfer.
Today, Power Line Communications (PLC) provide a true potential to become commercially viable project as a possibility to use low and medium voltage electricity grid as a communication channel for high speed data by:
*improving business potential of electric utility networks
*a way to supply public telecommunication including telephony over power line
*whereas, only wide-spread data alternative xDSL broadband access on existing infrastructure
In-building PLC can be used to interconnect PCs or other devices within a building, using that building's electrical wiring. Access PLC extends that connection to the Internet, using electrical distribution wiring. Various electric appliances using internet applications such as are connected via LAN which is communicating data using Access PLC technology over power line with low voltage. The power line is connected with a power grid station and the backbone of that grid station is connected with superficial ISP Cityn.et routing packets to the web.
There are three major categories of PLC:
*Access PLC uses electrical distribution lines, overhead or underground, to provide broadband Internet access to homes and businesses.
*In-building PLC systems are designed to use the electrical wiring within a building to network computers.
* Control PLC operates below 500 kHz, and is used by electric-utility companies to control their equipment using the power-lines as transmission lines.
HOW PLC WORKS?
Power Line Communication is the transmission of data along the utility powerline network. This holds true for access, last mile, and in-premise electrical networks. All three segments of powerline networking are currently enjoying breakthrough and emerging technologies that achieve ethernet-like bandwidth (2Mbps - xyMbps) in all three segments.
Power grids transmit electricity in three typical voltages: high, medium, and low. The medium and low voltage grids are the domains where PLC technology companies are currently introducing their products (high voltage is currently under research). Medium voltage is the power line coming from the utility substation, where voltages range in the tens of thousands (typically < 69kv and sometimes considered sub-transmission), to the low voltage step-down transformer. The transformer "steps-down" the medium voltage to the 240/120 three-wire (one ground, two 120 volt wires) low voltage output lines that enter the home or business. The delivery of electric from generation through distribution utilizes alternating current (ac) at a frequency of 60Hz. When entering an end-premise site, the 60Hz ac is reduced to the low voltage direct current that is required for most electronic devices.
Power Line communications takes advantage of the medium voltage power grid and the last mile primary and secondary distribution network that extends to the customer premise sites. In certain instances, a blend of different broadband solutions may be the required, functional design, e.g., PLC over medium voltage connected to a last mile or backhaul broadband fiber, wireless or copper solution. There are important differences between designing broadband networks for rural and urban geographies. A rural geography may utilize significantly more transformers due to distance limitations, potentially requiring additional capital expenditures and labor expenses for a utility to implement a network. In contrast, an urban area is able to serve more customers from a single transformer since the population density is increased. Each scenario will require network design decisions from the beginning.
Customer Premise Equipment (CPE) at the substation may implement a Public Switched Telephone Network (PSTN) backhaul connection (i.e. T1, E1, DS3) which connects to a headend PLC unit.
This unit connects to the medium voltage grid. Repeater units or similar headend units are placed on the medium voltage grid at intervals depending on the vendor. The signal either passes through or around the transformer and conditioners depending on the vendor's technology. DSS (digital spread spectrum) signals pass through line equipment and are less expensive and easier to deploy. OFDM (Orthogonal Frequency-Division Multiplexing) signals do not pass through line equipment and therefore must bypass it via a bridge or coupler device (copper or fiber). Many technologies use passive couplers, some use active couplers where a device exists on each side of the transformer or line conditioner. At this stage the signal is asserted onto low voltage lines. End users plug a PLC modem into a power outlet in the home or business that has a connection to the home computer. The end user now has an "always-on" high-speed Internet access connection.
EVOLUTION OF POWERLINE COMMUNICATIONS
1950s: The first technique to use power lines to control messages called the "Ripple Control," was developed. This technology used low frequencies (100-00 Hz) giving a low bit rate and a demand on very high transmitter power, often in the region of several 10kW. The system provided one-way communication and was used in the management of street lights, load control and switching tariffs.
MID 1980S: Investigation of the use of the electricity grid as a medium for data transfer began. Frequencies of 5 to 500 kHz were studies, with the focus on signal/noise levels and attenuation of the signal by the grid.
LATE 1980S: Bi-directional communication was developed.
LATE 1990S: The transmission of data signals over powerline at reasonable speeds has made advances and has been tested worldwide.
TODAY: PLC technology provides connection and data transfer over existing electricity networks ("power lines") and currently allows transmission speeds of 1 Mbps and far beyond! The electricity network consists of three levels: high, medium and low voltage.
For Local Loop-PLC transmission, low and to some extent medium levels are used. The low voltage network comprises lines from low voltage transformers up to the electricity meter in every property. Telecoms transmission is realized via this part of the network, from the transformer to the customer premises.
Effectively , PLC technology turns the low voltage level into a "local loop" data transmission infrastructure. In general a PLC system should consist of two basic elements, one at the transformer and the second at customer premises, that send and receive data. However, "power lines" not only exist outside of building, but also within.
The in-house electricity lines can be used for high speed transmission enabling the provision of Home Networking solutions. PLC offers an opportunity to create an innovative bundle of services and applications. Besides the fact that telecommunications services are now possible via the power line network, bundling of energy and telecommunications services might be feasible. New dimensions in services are provided. It may be of strategic importance to deliver broadband access to every home and office by creating differentiation strategies on the highly competitive markets.
ON GOING DEVELOPMENTS IN PLC
Originally PLC was developed for low voltage power networks using high frequency signals (1.6 to 30 MHz) which provide direct connectivity through galvanic connections and inductive coupling using modulation techniques such as GSKM (Gaussian Minimum Shift Keying), spread spectrum, and OFDM (Orthogonal Frequency Division Multiplexing) which is most recommended. Today PLC systems have a capacity of 2-10 Mbs depending on the manufacturer and the projected capacity will be 100 Mbs symmetric bandwidth. New systems for communication will be operating on medium voltage ranging from 10-20kv and field trials for such PLC systems are in place for prototypes working in Germany, Spain and Sweden. PLC systems will ensure increased transmission efficiency with low energy emissions with longer signal reach and cost-effective solutions. Even Germany and Sweden have commercially rolled out PLC network with 4000 and 3000 users connected respectively.
Keeping in view that PLC has been developed as a broadband technology all technologies available on computing are also available on PLC system, with one exception that is high quality video steaming which is only available FTTH (fiber to the home). Therefore, PLC directly competes will at the last mile access level for data communication provision with broadcasting networks and telecommunication networks.
COMPARISON ON COMPETING TECHNOLOGIES
St3.able networking. Widest bandwidth.
Extremely expansive Intensive cabling required Sub-networking difficult.
Wide bandwidth Fairly stable Cabling may not be needed
Developed infra required
Highly depend on line quality Sub-networking difficult
Fairly stable Wide bandwidth
Quality highly depends on the number of subscribers. Sub-networking difficult
Easy access Sub-networking possible
No cabling required
Still underdevelopment. High equipment cost
Easy access Simple plug-in sub-network
No cabling required
Not proven yet Depends on the number of subscribers connected to the transformer
*PLC enables power utilities telecom operators to offer their customers solid business services such as High Speed Internet, telephony and additional services.
*PLC enables power utilities to build their market position by enhancing their corporate image as an innovator and trendsetter in the latest broadband communication.
*Provides alternative "last miles" access that supports the entire process of the deregulation of the telecom market.
PLC competes directly with other available options for broadband access services both in wire and wireless which makes the work for telecommunication or data operators even more difficult to ensure the dominance of single-point-of-access at the customer premises which has already been threatened by broadcasting media service provides such as Cable Network Operators.
Market opportunity for power utilities
*Growing market for Broadband communications is rapidly growing
*Utilizing existing infrastructure (power grid)
*Utilizing existing customer base (distribution strategy)
*Utilizing existing business models
*Utilizing existing telecom capabilities
*Versifying existing products and services
*Adding additional Broadband PLC services
*Generating a higher return on investment (ROI)
*Creating a corporate image of an innovator (trend setter) in the mark
*Building shareholders' confidence with a clear corporate vision
*Building closer connections with the customers
*Incorporating strategic municipality issues
* Optimizing existing fiber optic infrastructures
PLC DISTRIBUTION NETWORK
Low voltage access PLC uses the substation as the installation "cell". The business plan needs a reasonable amount of customers available in the substation area (> 30 connected customers) where the technology is independent of distribution voltage and frequency. The only thing is that there must be space in substation for PLC central unit and backbone modem and the substation must have a backbone connection like optical fiber, radio link, or satellite connection.
At the moment it is commercially viable for developing small scale PLC cells containing 100s of customers sharing an electricity grid in a locality whereas, the investment considerations per PLC cell are based on demography and technical conditions.
PLC FORUM: STANDARDIZATION
The PLC forum is a leading international Association that represents the interests of manufacturers, energy utilities and research organizations active in the field of access and in-home PLC (power line communications) technologies. The PLC-Forum was formed with the aim of uniting and representing the interests of players engaged in power line Communications (PLC) from all over the world. The Board has in total 7 members including the chairman from different sectors (utility, manufacturers/developers, others). The PLC-Forum was established by 51 founding members out of 17 countries in 3 continents. The PLC-Forum concentrates on improving PLC products, Services, PR, Marketing and Finance, all with a view to aiding PLC providers, Power Utilities, and Service Providers to achieve a more successful penetration into the market. PLC forum was created in Interlaken (Switzerland) at the start of 2000.
The association's main objectives are the following:
REGULATORY ISSUES: Lobby directly and support members' lobbying activities so that a satisfactory regulatory framework for PLC can exist.
TECHNOLOGIES: Share visions, problems and solutions within the Forum, push coexistence and interoperability/ standardization so that technology is not a market-limiting factor.
BUSINESS CASE: Support members in the creation of appropriate commercial and financial models.
MARKETING: contribute to a wide awareness of PLC potential through involvement in major events, information dissemination, press activities, etc.
EXISTING PLC STANDARDS
There are four major power line standards in use today: X-10, CEBus, LONWorks, and Smart House. It is important to note that while all of these standards support power line communications, most of them also support other communications media, such as Infrared (IR) and Radio Frequency (RF). Some of the key features of these standards, along with the media which they support are summarized in the table below.
CEBus (EIA IS-60)
Electronics Industry Association (EIA).
Further developed by CEBusIndustry Council (CIC)
Echelon Corp. Testing and certification programs led by LONMark Interoperability Assoc.
Smart House Limited Partnership (Smart House LP) for the National Association of Home Builders
Powerline. X-10 manufactures devicesfor other media, but there are no standards for them
Powerline Twisted Pair
Eventually Fiber Optic
Powerline Twisted Pair
Third party transcievers
Custom made wiring available fromthree sources
Max. Data Rate
10 kbps, Add'l. support for video, audio, and data
610 bps to 1.25 Mbps
50 kbps, Add'l. support for coaxial distribution
Proprietary, company does not license others to use it.
Public domain, does not require a license. Certification required to use the CEBus logo.
License required. Certification required to use the LONMark logo.
Low to moderate
Low to moderate
Moderate to high
Existing and new homes
Existing and new homes
Existing and new homes, commercial and industrialbuildings, industrial automation, automotives
Mostly new homes, some light commercialbuildings
BUSINESS CASE: KOREA ELECTRIC POWER DATA NETWORK (KDN)
In January 1992, KDN was founded as a subsidiary company of the Korea Electric Power Corporation (KEPCO), with the purpose of developing in the growing field of information and technology. Since this time, KDN has shaped electric power information communication systems, the national information infrastructure of Korea, industry intelligence networks and various key national industry IT systems and has developed into a complete information and communication corporation.
KDN envisions establishing itself as Korea's leading comprehensive information telecommunication provider that provides high-quality e-Biz solutions in three key information telecom areas of e-Service, e-Infra and Automation. KDN provides comprehensive services in information system consulting, high-speed communication infrastructures, construction of automatic systems and e-commerce.
KDN is concentrating on constructing the power line Internet business, "the 4th communication network", which will enable a variety of data communications via power lines. KDN's power network equipped both with knowledge in construction & management of information communication network in the field of electric power and nationwide integrated database on electricity and communication facilities. Uses power (electric) lines and electrical outlets as communication medium. KDN PLC system operates by dividing low frequency (50-60Hz) electricity routes of power line and transmission path of high frequency (hundreds of KHz - dozens of MHz) for communication use. This makes it possible to provide a wide range of communication services at a low cost, such as high-speed internet, digital telephone and home networking etc. KDN PLC sysem enables building of high-speed home automation linking a variety of electronic appliances into one, such as digital TV, digital refrigerators, PCs, electric lamp etc.
*TELECOM VS. POWERLINE OPERATORS: The greatest challenge PLC poses is the issue of convergence, which has been long debated for telecommunication and broadcasting service provision.
*REGULATION: With the sector specific regulation of telecommunication, broadcasting and power utility, the challenge of convergences makes regulatory task more and more difficult as the business and industry separation becomes more and more blur.
*STANDARDIZATION: Until now there has been the evolution of product standards, but with PLC in place there is now the question of establishing network standards as well. Network standards have not been needed as there have not been products producing network emission. With emergence of network technologies such as PLC, xDSL, LAN, etc all are emitting network disturbances in different frequency ranges. Therefore, the standardization must also become network based.
*SECURITY & RISK: Power line has always been a security risk and as soon as the market adopts PLC system the greatest challenge will be the risk management both at physical and virtual levels. As PLC system will expose the data communication related risk into the power line utility network as well creating a serious challenge for security experts.
*LIBERALIZING POWER LINE UTILIZES: By and large, most of the power line utilities are government owned enterprises. There is a similar need to liberalize power sector in lines with the telecommunication sector through privatization, introduction of competition both at national and regional levels, even to the extend of metropolitan level. Only then the true fruits of PLC can been utilized.
*DIGITAL DIVIDE: As the cost of establishing new telecommunication or information network is a serious business of millions of dollars, PLC can become a powerful tool to bridge the gap created through digital divide.
*SINGLE SOURCE OF ACCESS: PLC provides last mile access to the consumer in a cost efficient manner compared to traditional or new telecommunication technologies which makes it a clear market choice for future.
*COMPETITION PROMOTION: There has long been a debate of unbundling local loop in telecommunication services, and PLC network provide an efficient way both for power line and telecommunication infrastructure operators to mutually share resources for better market positioning and defining cheap technology solutions to the society at large.
*INCREASING TELECOMMUNICATION ACCESS: With liberalization of telecommunications, the key challenge is to provide telecommunication access to under-developed areas as access to communications is seen as a basic human need identified by UN for improving living standard of a well being and a community at large. The regulatory body has to set license conditions such as Universal Service Obligation (USO) to ensure that the current telecom operators share a percentage of their revenue with telecommunication access provision to under-developed communities and regions. Here, PLC can play a vital role in communication access provision.
LESSONS FOR PAKISTAN
Keeping the confusion of convergence between broadcasting and telecommunication, the telecommunication sector and telecom regulator seems not to be ready for another future-shock in the form of Power Line Communication. Pakistan has yet to liberalize telecommunication sector, implement competition rules of significant market power (SMP), interconnection, USO, license conditions and quality of service. With snail pace liberalization process in telecom, where the performance of regulatory body PTA and telecom sector policy maker, the Ministry of IT & Telecom are to blame. Pakistan today is far behind even from India to implement sector specific regulation in telecom where the world has moved to general competition rules. If this is the case of telecom, is Pakistan ready for liberalizing power sector? May be!