Power Line Communications

Transcript

ANEEL Workshop sobre Power Line Communications Brasilia, May 3-4, 2007 Power Line Communications: Technology and Market Perspectives Dr. Stefano Galli Lead Scientist, Panasonic [email protected] Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. Outline of Talk Applications World Trends and Market Status IEEE standardization efforts PLC industry associations Major Challenges Conclusions Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 2 Applications: Outdoor for Internet Access From ADVANCE, March 2005 Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 3 European Power Supply Network Structure Single phase: phase hot/neutral connectors (sometimes separate “earth” wire) – typical for residences 240V (UK) or 220V (rest of EU), but harmonization process towards 230 V (±10%) Three phase: three hot wires and one return – 230V/400V (typical for homes in Germany, Sweden and Finland), but sometimes 127/220V (Finland and Belgium), and 230V and no neutral in the supply - outlets are wired between two phases (Scandinavia) Important characteristics: – Access network in Europe is composed of LV lines – Most cables are underground – Average number of households per LV transformer is 100 Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 4 USA Power Supply Network Structure Single phase: phase hot and neutral connectors –120V AC, sometimes separate ground wire Two phase: phase two hot conductors (opposite polarity) with one neutral. – Typical 120V AC (120/240V AC split phase), but sometimes two legs of 120/208 wye (apartment complexes) Three phase: three hot wires and one return –120/208 V, but rare for homes Important characteristics: – Access network in the US is composed of both MV and LV lines – Most cables are overhead – Average number of households per LV transformer is 10 Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 5 Why outdoor? • World’s most pervasive infrastructure, 4B+ customers • Broadband demand continues to grow, and current solutions (DSL/Cable/Satellite/Fiber) are not as pervasive as power lines • Privatization and liberalization of the energy sector will certainly push companies to investigate and develop strategies for differentiating their services • Cost effective way to reach customers, not only those that have no opportunity to receive broadband in any other way • Limited investment needed since infrastructure is already in place. Moreover, utilities have also over 50,000 cable-miles of fiber optics already installed along HV lines Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 6 Enabling factors • The 1996 Telecom Act allows utilities to provide telecom services, and many are already doing so. • Flat growth and low margin will require utilities to focus on the expansion of value added service capabilities • Privatization and liberalization of the energy sector will certainly push companies to investigate and develop strategies for differentiating their services • Limited investment needed since infrastructure is already in place. Moreover, utilities have also over 50,000 cable-miles of fiber optics already installed Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 7 Map of Boston (from Bruce Renz, Amperion, CCNC’04) FIBER MV Grid (Single Phase Spurs) MV Grid (3Phase Mains) Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 8 USA BPL Deployment From Brett Kilbourne, UPLC Conference Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 9 USA BPL Deployment From Brett Kilbourne, UPLC Conference Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 10 Applications: Smart Grid From ADVANCE, March 2005 Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 11 Applications: Smart Grid • Smart grid applications: – Automatic Meter Reading – Peak shaving – Transformer monitoring – Real time power quotation • PLCs as the enabler for truly pervasive and ad-hoc networks: –Traffic lights, lamp posts, etc. can easily become network nodes – Municipal applications – Security applications • Enables utilities to generate revenue, save money in operating efficiencies, and obtain better grid reliability Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 12 Applications: Indoor (Home LAN) From ADVANCE, March 2005 Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 13 Inside wiring environment • International: International – wiring system uses a star (e.g., a single cable feeds all of the wall outlets in one room only) or tree arrangement – ground bonding at the main panel • Europe: – two wire (ungrounded) or three wire (grounded) outlets – If three phase supply is used, separate rooms in the same apartment may be on different phases • UK exceptions: – special rings: a single cable runs all the way round part of a house interconnecting all of the wall outlets; a typical house will have three or four rings. – neutral not grounded in the home – New builds: builds three phase with four of five wires (neutral, ground) – Problematic old wiring: wiring two-wire 1 phase, neutral and ground share common wire Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 14 Inside wiring environment NM-B BX Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 15 Inside wiring environment • Wiring and grounding come in many flavors, and this makes modem design much more challenging. • However, international harmonization is happening: – Typical outlets have three wires: hot, neutral and ground – Classes of appliances (light, heavy duty appliances, outlets, etc.) fed by separate circuits – Neutral and ground separate wires within the home, except for the main panel where they are bonded Although complex topologies may exist, today’s regulations can simplify analysis of signal transmission Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 16 Why Indoor? y Home Networks (HN) will likely flourish: – Internet access within multi-computer homes – Success of broadband access – HDTV (YG in 7/04: 60 M by 2008) • High data rate PLC-based backbone network give additional motives for HN success: – As complexity moves to the edge of the network, the in-home LAN becomes a factor in QoS PLCs can ensure bit rate availability with QoS – Access lines will no longer terminate on a single device PLCs can support a plethora of networked devices – Once the bitpipe is in place, applications will multiply PLCs allow for every “powered” device to be a network node – Wired and wireless networks will coexist in the home Î synergy PLCs and wireless can provide truly ubiquitous home networking Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 17 Why Indoor? • Most pervasive medium, multiple outlets in every room • No new wires, but whole home is networked • Every “networkable” device is connected to a power outlet: many devices become potential target for added value service • Very high bit-rate, today 200 Mbps chips by DS2 and Intellon and Panasonic • Has advantages over other solutions: • Wired: • Ethernet • HomePNA • Coax • Wireless: • HomeRF and Bluetooth • UWB • 802.11a/g Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 18 Why Indoor? Ethernet • New wire installation needed • Each node must be connected to the Ethernet • Requires hub/router Coax • Lack of ubiquity of cable outlets within a home • Compatibility with existing services (TV, modems) HomePNA • • • • Not many phone outlets within a home Attenuation at high frequencies, limited data rate Compatibility with VDSL Short BTs create problems Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 19 Why Indoor? Wireless • • • • • Dead-spots Interference in unlicensed bands Needs a base station Costly at very high data rates HomeRF and Bluetooth • Range and data rate limitations • Coexistence with 802.11 • • UWB has range limitations QoS support is problematic for multimedia traffic The thrust for HN is not data sharing, but multimedia traffic Wired and Wireless solutions will coexist in the home Wired and Wireless solutions must complement each other Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 20 Why In-Vehicle? • PLCs allows for easy in-vehicle networking: – In any vehicles (from automobiles to ships, from aircraft to space vehicles), separate cabling is used to establish the PHY of a local command and control network which is becoming broadband – The in-vehicle power distribution network may well perform double-duty, duty as an infrastructure supporting both power delivery and broadband digital connectivity. – Weight, space and cost savings (aircraft, auto). – “Plug & Play” • Boeing, Toyota, Nasa, Valeo, Ford show interest in PLCs Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 21 World Trends Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 22 Main PLC companies Ambient Corporation • Publicly traded • MV and LV solution • Trials with ConEd and Southern Telecom (5-8 Mbps) Amperion • AEP/Cisco/Redleaf • MV solution • Trials with AEP, PPL, Progress Energy (20 Mbps) Current Technologies • Privately held • End-to-End solutions, mainly on LV • Trials with Cinergy and PEPCO (3-5 Mbps) Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 23 Main PLC companies PowerComm Systems • Privately held • MV and LV solution • Trials with Fayetteville Electric System and Cullman Electric Cooperative Main.net • Privately held (ABB) • No transformer bypass necessary • Trials with Ameren, PPL, few municipalities (500 kbps) • Newer version using OFDM and transformer bypass Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 24 Main PLC companies DS2 • Privately held (Endesa, Hitochu) • MV and LV chips • On Jan 7, 2006, announced the 1st 200 Mbps chip (HomePlug AV) Intellon • Privately held • Specialized in HN, first to produce HomePlug 1.0 chips (14 Mbps) • HomePlug A/V chip at 200 Mbps • Many agreements for PLC-WiFi symbiotic solutions (Linksys, NetGear) Panasonic • HD-PLC modem • Wavelet-OFDM , 200 Mbps • Focuses on in-home applications Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 25 International Regulatory landscape for PLCs ITU IEC CISPR Inter Governmental (e.g. OPERA) European Commission European Parliament CIGRE CENELEC IEEE ETSI National Standards Organizations Government Regulators (e.g. FCC) Industry Associations and Specification Groups (i.e. HomePlug, UPLC, UPA, CEPCA, PUA, etc. etc.) Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 26 IEEE ComSoc Efforts • The IEEE want to have a role in the standardization process • The first society to promote standardization was PES, then came the others (EMS, AP, ComSoc) • In 2004 IEEE ComSoc created the Technical Committee on Power Line Communications (TC-PLC) (http://www.comsoc.org/bopl) • S. Galli, Panasonic, Chair • L. Lampe, University of BC, Vice-Chair • R. Fantacci, University of Florence, Vice-Chair • Broad consensus: 180+ members (industry, academia, retail) • The interests of TC-PLC span all the areas of PLCs, e.g., access, home networking, in-vehicle applications, etc. • The TC-PLC will organize events in the PLC area, sponsor PLC conferences, contribute to the organization of technical events along ComSoc flagship conferences, and will promote the realization of special issues on leading IEEE journals. Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 27 IEEE ComSoc Efforts • Recent special issues: • IEEE Communications Magazine: Magazine “Power line local area networking,” April 2003 • IEEE Communications Magazine: Magazine “Broadband is Power: Internet Access Through the Power Line Network ,” May 2003 • International Journal of Communication Systems: Systems Powerline Communications and Applications, ” June 2003 • IEEE Journal on Selected Areas in Communications, Communications Power Line Communications, July 2006 • Eurasip Journal on Applied Signal Processing: Emerging Signal Processing Techniques for Power Quality Applications, to appear 2Q07 • Eurasip Journal on Applied Signal Processing: Advanced Signal Processing and Computational Intelligence Techniques for Power Line Communications. Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 28 IEEE Standardization P1901 • Focuses on MAC/PHY aspects and was officially approved by the IEEE Standards Board on 4 June 2005. • The Working Group is chaired by Jean-Philippe Faure (Snider Electric), Vice Chair is John Boot (Current). • P1901 operates as an entity standards development group, where all members are organizations instead of individuals. • As of this date, 48 entities are members. Much of the last 6 months work has focused on developing detailed technical requirements in 3 major clusters – Access, In-Home, and Coexistence. • All FTRs finalized, issued a call for submission with deadline June 4 • Meetings are open to all (members and non-members). • More information can be found at the P1901 website at: http://grouper.ieee.org/groups/1901/index.html Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 29 IEEE Standardization P1775 • The P1775 effort focuses on specific measurement issues associated with BPL emissions. • This group is chaired by Aron Viner. • This group has formed three task groups focused on immunity measurements methods, emissions measurements methods, and overall network description. • The next P1775 meeting will be during ISPLC 2006. • Further information is available from the chair at [email protected] Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 30 IEEE Standardization P1675 • P1675 is focused on developing standards for equipment testing and installation. • This effort is chaired by Terry Burns. • An initial draft has been produced, and is currently being reviewed and revised by the Working Group. • The next P1675 meeting is scheduled during ISPLC 2006. Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 31 Industry Associations: Homeplug Powerline Alliance (HPA) • Members 77, Sony, Sharp, Motorola, Intel, Intellon, RadioShack, Texas Instruments, LG, Linksys, Comcast. etc. • A non-profit organization, provides a forum for the creation of open specification for home power line networking products and services • Traditionally focused on the indoor environment only. • Traditionally focused on the indoor environment. Two indoor specifications: 1.0 (14 Mbps) and A/V (200 Mbps) • Recently, the HomePlug Access BPL Working Group initiative was recently launched. HomePlug BoPL refers to the outdoor environment of power lines. Necessity of addressing outdoor: • Wires used in the home are the same of those coming from outside, and the utilized spectrum is the same • Home networks coming off a common transformer may interfere with each other. Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 32 Industry Associations: Universal Powerline Association (UPA) • Ambient Corporation, Current Technologies International, Powerline Communications, Corinex Communications, DS2, Electricite de France, Ilevo- Schneider Electric Powerline Communications, Itochu, Sumitomo Electric Industries, Toyocom, Netgear. • In May 2004, the UPA interest group was established and a Memorandum of Understanding was signed in September 2004. • A non-profit organization • Trade association working to harmonize global standards and regulations, and to deliver UPA certified products which comply with agreed specifications. Covers both home, access, and coexistence. Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 33 Industry Associations: Consumer Electronics PLC Alliance (CEPCA) • Founded July 2005 Members: 17 Board: Hitachi, Sony, Panasonic Toshiba, Mitsubishi • Established to promote and continuously advance high speed PLC technology to utilize and implement a new generation of consumer electronics products through the rapid, broad and open industry adoption of CEPCA Specifications • The Purpose of CEPCA is to: • Completely remove the mutual interference between PLC systems that employ different technologies but use the same bands • Create and standardize technical specifications that enable different PLC systems to coexist and achieve optimal performance • Enable CEPCA implementations to become an essential function to the widespread usage of CE devices Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 34 Industry Associations: Open PLC European Research Alliance (OPERA) • It is a European R&D Project with a budget of about 20 M Euros. • Scientific and technological objectives of the project are: • Improve current PLC systems, both conditioning the power grid (using couplers and filters) and improving PLC equipment. • Develop optimal solutions for connection of the PLC access networks to the backbone networks. • Standardization of PLC systems. Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 35 Industry Associations: United Power Line Council (UPLC) • The United Power Line Council (UPLC) is an alliance of electric utilities and technology companies working together to drive the development of Broadband over Power Line (BPL) in a manner that helps utilities and their partners succeed. • UPLC's efforts are focused in four strategic areas: Business Opportunities, Regulatory & Legislative Advocacy, Technical Operability and Utility Applications . Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 36 Challenges: Technical Issues • Interference issues in the HF band • Better understanding is needed, theoretical and experimental work • Modulation and coding can help reducing interference • There are very few channel models available: lack of general results in communications theory • For the optimization of any communications system, it is imperative to understand the channel • What is the “average” power line channel? • Many differences between countries in the mains grid • Plethora of grounding and wiring practices, wide variability of performance • Channel standardization needed • High data rates with QoS, robustness, coexistence, security • More work in transceiver “robustness” optimization • MAC issues for outdoor/indoor coexistence • Security Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 37 Challenges: The Business Case Issue • PLC technology is still “young” and evolving • Do we really need another access solution? • Do the power utility companies really want to enter telecom? • Is there a solid business case? • Deregulation and liberalization are fairly recent • Lack of standardization and interoperability of products • Necessity of hybrid infrastructures, between PLC-based networks and existing wireless/fiber/copper-based ones Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 38 The Biggest Challenge: Coexistence • An in-home power line network is not contained within the home • An access power line network will always “leak” into the home • Utility power meter can act as a gate, but in some cases offers only a few dB of signal attenuation • Signals from within the home can reach out to the Utility LV transformer and may continue on into neighboring homes or residences • Problem is worsened by: • An increase in residence density. Rural areas are less affected, if at all. • Cross-cable coupling in multiple dwelling units (i.e., apartments) In-home and utility power line networks will collide In-home power line networks will collide with each other Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 39 The Biggest Challenge: Coexistence Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 40 The Biggest Challenge: Coexistence • Power line cables are a shared medium, like coax cable and unlike DSL. Similarly to cable, mass deployment causes backbone capacity issues to arise • Signals in your home are interference for your neighbor, and viceversa, regardless of whether you are subscribed to access or not • Not only complicated MAC problem, also security issues… but not that different from wireless 802.11 Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 41 The Biggest Challenge: Coexistence • There is no demarcation between access and in-home power line cables Î it is a bus running from sub-station transformer to every plug in the home • Access signals and in-home signals must co-exist Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 42 The Biggest Challenge: Coexistence Access Repeater Throughput (Mbps) AV speed Access CPE* AV PLC Access status (4–28MHz) Off On In phase 70 50 Cross phase 60 20 Access speed In-Home status Same phase AV PLC (3–13MHz) Off On In phase 30 0 Cross phase 30 0.8 Cross phase *CPE = Customer Premise Equipment Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 43 QoS Issues • To complicate things even further, the access and in-home networks have different requirements Requirements Control Indoor Access HDTV (28Mbps x 2, 200msec) NO YES NO SDTV (8Mbps, 200msec) NO YES NO Audio (6Mbps, 15msec) NO YES NO Home Control (250kbps, Low Cost) YES YES NO VoIP (64kbps x 2, 10msec) NO NO YES Long reach (500m-1Km) NO NO YES Best Effort NO YES YES Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 44 Conclusive Remarks • We have today a very good understanding of the PL channel • PL channel more deterministic than originally thought – Determinism should be exploited for transceiver optimization • Plethora of grounding and wiring practices, but harmonization of regulations can simplify analysis of signal transmission – Wiring and grounding practices must be taken into account • Lack of traditional funding kept PLC research out of academia, so that most work has been done within an industrial environment and has been directed towards winning skepticism – Lack of a solid theoretical approach! • System optimization is challenging – PLCs is probably the most inter-disciplinary field we have • Many open problems in the PHY/MAC – Good research field, many opportunities Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 45 Conclusive Remarks • PLCs is a very promising technology: cost effective, ubiquitous and existing infrastructure, good candidate for many applications such as access, home networking, in-vehicle, smart grid. • Success of access applications depend essentially on power utilities • Not clear yet if utilities want to enter telecom world, more interest seems to be present for smart grid applications • In-home LAN applications appear to have the brightest future in the short/medium term • Fundamental issue for success of technology is coexistence: • Coexistence is the ability for different power line systems to function simultaneously on the same power line at acceptable levels of performance. • CEPCA accomplishes peaceful coexistence by creating a common communication channel shared by all systems Copyright © 2007 Panasonic R&D Company of America. All Rights Reserved. 46