Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Serial digital interface wikipedia , lookup
Immunity-aware programming wikipedia , lookup
Opto-isolator wikipedia , lookup
Telecommunications engineering wikipedia , lookup
Spectrum analyzer wikipedia , lookup
Index of electronics articles wikipedia , lookup
History of telecommunication wikipedia , lookup
Powerline By Yong Soo Deutschle & Sebastian Graf Table of contents • • • • • • • • • • History of PLC Transmission media The last mile Regulations Powerline in the OSI-Model Digital Powerline Protocol Spread spectrum Powerline Exchange Protocol Future aspects Conclusion History of PLC • Introduced in the 1920s – Energy providers • Used in the power automation (high voltage lines) • Later on used for control of street lightening • Home use started in 1980s – Baby phone • Today : new alternative for „the last mile“? Transmission media • Low & high voltage net was assigned to carry energy • Reason for basic problems concerning data transfer – Big noise – High absorption – Huge distortion • Needs repeaters every 300 –600 meters (last mile) The last mile outdoor master indoor master PL Modem consumer Regulations • Europe: – CENELEC: • Data communication in low voltage networks only up to 148,5 khz • USA & Japan: • Up to 540 khz Powerline in the OSI-Model 4 Transport 3 Network PLX (Powerline Exchange Protocol) 2 Data Link 1 Physical DPL (Digital Powerline Protocol) Table of contents • • • • • • • • • • History of PLC Transmission media The last mile Regulations Powerline in the OSI-Model Digital Powerline Protocol Spread spectrum Powerline Exchange Protocol Future aspects Conclusion Digital Powerline Protocol • Narrow spectrum • Usage of very narrow „spectrum gaps“ is possible • Uses high levels -9 • Bit error ratio = 10 • chimney concept Spread spectrum concept • Signal is spread over a huge frequency spectrum • Non-sensitive for conduction bound interfering signals • Uses low levels • Very expensive to implement Powerline Exchange Protocol • Covers the layers 2,3,4 of the OSI-Model • Hybrid MAC-protocol – Ethernet – Token Ring – Wireless LAN – CEBus • Datagram Sensing Multiple Access (DSMA) – Adapted from CSMA Future aspects • Internet usage: – 2 providers left: • MVV Energie AG – Product name : Vype • DREWAG – Product name : PowerKom Future aspects • DREWAG PowerKom availability Conclusion + no additional cable installation required + high flexibility + adaptable to all power networks + high bandwith (theoretical up tp 20 Mbit/s) Conclusion - no security high technical equipment needed high costs no standards Incompatibilities between USA & Europe Problems in regulation of frequencies Questions? Questions • Which are the two concepts of PLC data transmission? – Chimney – Spread Spectrum Questions • Which layers in the OSI-Model are covered by PLX? – Data Link, Network, Transport (2,3,4) Questions • What is the last mile in the PLC? – The way from a outdoor master to the end consumer Questions • What is DSMA and how does it work? – Datagram Sensing Multiple Access – Adapted from CSMA. – First listen – then send.