Transcript Powerline - Roggeweck

Powerline
By Yong Soo Deutschle & Sebastian Graf
Table of contents
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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
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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.