Overview of CEPCAand
Approach to PLC Standardization
July 19, 2006
Consumer Electronics Power line Communication Alliance (CEPCA)Technical Work Group
[Presented by Mark Eyer, Sony]
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Overview of CEPCA and Approach to PLC Standardization
1. Necessity of Coexistence– Result of collision experiment – Requirements for Coexistence– Use Case analysis– Basic system requirements– Requirements from Consumer Electronics manufacturers
2. CEPCA solution
3. Approach to standardization– Activity of Technical WG (TWG)
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A Definition of Coexistence
o Different PLC systems must be able to operate simultaneously on a common electrical medium without degradation in performance except for the reduction in bandwidth due to fair sharing of the medium.
ETSI Coexistence Workshop
Kaywan Afkhamie, Intellon Corporation
September 22, 2005
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Collision Experiment with Modems using Different Methods
Necessity of Coexistence
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Necessity of CoexistenceConfiguration of collision experiment system
Interference tests using pseudo-transmission path– Four types (technologies) of modems
• two high-speed, two medium-speed
Modem A1Modem A1
PCPC
Modem A2Modem A2
PCPC
Modem B1Modem B1
PCPC
Modem B2Modem B2
PCPC
Spectrum Analyzer
Spectrum Analyzer
ATTATT
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Necessity of Coexistence: Result of collision experimentMedium-speed system (A) vs. High-speed system (B)
Type of ModemActual speedin standalone
Actual speedat collision
A: Medium-speed system(data length 255B)
400 kbps 80 kbps
B: High-speed system(data length 1500B)
100 Mbps (ATT 0dB)
19 Mbps (ATT 50dB)60 Mbps (ATT 0dB)< 1 Mbps (ATT 50dB)
Modem A1
Modem A1
PCPC
ModemA2
ModemA2
PCPC
modemB1
modemB1
PCPC
ModemB2
ModemB2
PCPC
SpectrumAnalyzer
SpectrumAnalyzer
ATTATT
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Necessity of Coexistence: Result of collision experimentHigh-speed system (A) vs. High-speed system (B)
Type of ModemActual speedin standalone
Actual speedat collision
A: High-speed system(data length 1500B)
147 Mbps 90 Mbps (ATT 0dB)
131 Mbps (ATT 10dB)
B: High-speed system(data length 1500B)
125 Mbps (ATT 0dB)
123 Mbps (ATT 10dB)
< 1Mbps (ATT 0dB)
< 1Mbps (ATT 10dB)
Modem A1
Modem A1
PCPC
ModemA2
ModemA2
PCPC
modemB1
modemB1
PCPC
ModemB2
ModemB2
PCPC
SpectrumAnalyzer
SpectrumAnalyzer
ATTATT
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Necessity of Coexistence: Result of collision experimentHigh-speed system (A) vs. High-speed system (B) (FDM)
Type of ModemActual speedin standalone
Actual speedat collision
A: High-speed system(data length 1500B)
77 Mbps 77 Mbps
B: High-speed system(data length 1500B)
56 Mbps 40 Mbps
Modem A1
Modem A1
PCPC
ModemA2
ModemA2
PCPC
modemB1
modemB1
PCPC
ModemB2
ModemB2
PCPC
SpectrumAnalyzer
SpectrumAnalyzer
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Summary of Collision Experiment
Physical layer speed deteriorates significantly upon collision
– Demonstrates that coexistence is indispensable
Less deterioration if frequency bands separated– Effectiveness of frequency band division is
confirmed– Time division is expected to be effective as well
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Spatial Isolation
Influence by interference was not observed with SNR > 30 dB– Possibility for spatial reuse of frequency
Modem A1Modem A1
PCPC
Modem A2Modem A2
PCPC
Modem B1Modem B1
PCPC
Modem B2Modem B2
PCPC
Spectrum Analyzer
Spectrum Analyzer
ATTATT
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Coexistence Requirements and the Solution
Analysis of system requirements– Categorization of application areas
Definition of requirements for system specification– Basic system requirements– Requirements from CE manufacturers– Other system requirements
CEPCA solution– Specification for coexistence system – Summary
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Scope of PLC Applications
Access systems and In-home systems Assumed Use Cases / applications Assumed worldwide use Target: systems using the 2-30 MHz band
Category Field Use Cases / Applications
Access systems
Outdoor distribution lines Broadband internet service
Voice service (VoIP)
Video service (IPTV)
Distribution lines for housing complex / In-building
In-home systems
In-home power lines AV streaming
Audio transmission
Broadband internet service
Home control
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Access indoor (housing complex)Transformer
HE
CPE
Internet
ISP
Den
Internet
TV
VideoPhone
Audio ServerPrinter
Audio
PC
Child's room
Living room
Child's room
TVVideo Server
PC
Use of in-building / housing complex network and in-home network Triple play (IP broadcast watching, VoIP, internet access) Multi-room distribution by in-home video server Home control (security camera video, electronic locking)
Fiber optics
ElectroniclockSecurity
camera
Entrance
Application Areas
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PLC rear speaker
Multi-room distribution system
PLC Audio Distribution Application
PLC enables new listening styles and greater user convenience
Combination with PC
Combination with portable audio player
Application – Audio
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ElectricLock
SecurityCamera
SensorAir Conditioner
Lighting
Entrance Living room Den
Lighting
Bed room Child's room
Air Conditioner
WindowBlind Air
Conditioner
Internet
Example of In-Home Control System
Integrated control of sensors, HVAC, lighting, blinds, & security cameras Coexistence must ensure quick response
Data transport could be lower-speed
Application – Home Control & Security
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Specification Required for Application
Application Transmission Rate (Mbps) Packet loss rate Latency (ms)
HDTV (MPEG-TS) 19.2–27
< 1 packet / 2 hours 200DV 28.8
Video Conference 0.128–2
Internet Streaming(Video)
0.1–4
High Quality Audio 1.411–5.644<1 sample / 80 minutes 10
Low Rate Audio 0.064–0.32
VoIP 0.128 (0.064 x 2)1% 20
Video Phone 2–8 (1–4 x 2)
Home Control 0.04 (0.01 x 4)n/a 300Monitoring Camera
(JPEG)0.250 (VGA)
Four Application Areas Coexist
Video system Audio system Voice system Home control system
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Coexistence Requirement and the Solution
Analysis of system requirements– Categorization application areas
Definition of requirements for system specification– Basic system requirements– Requirements from CE manufacturers– Other system requirements
CEPCA solution– Specification for coexistence system – Summary
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Basic System Requirement
Resources are fairly distributed to access systems and in-home systems Basic requirement: both access and in-home systems
preferentially can use available resources up to 50% Resources are efficiently utilized, accommodating sharing of unus
ed resources Resource allocation is variable, considering country-specific requi
rements
Among in-home systems, resources are distributed, focusing on efficient use Assumes each in-home system uses minimum necessary resourc
es for the given application User priority is respected when available spectrum is insufficient
1. The system should be able to utilize powerline resources (time and frequency) efficiently and fairly
1. The system should be able to utilize powerline resources (time and frequency) efficiently and fairly
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Requirements from CE Manufacturers
Achievement of both high-speed transmission and low-delay transmission High-speed transmission of Full-HD video stream (27 Mbps max) Delay time of audio or VoIP
(10 msec. for audio, below 20 msec. for VoIP)
Response time and reliability of operation Expected performance of consumer electronics is maintained with
PLC feature in use No additional user complexity involved
Assumed number of systems One Access system and several In-home systems coexist Up to four in-home systems have guaranteed resources available Assumed number of systems is not limited on best effort basis
2. The system is suitable for practicaluse cases / applications
2. The system is suitable for practicaluse cases / applications
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Other System Requirements
It is possible to apply to power lines all over the world Supports specifications of countries using electric power system
from single-phase two-wire to three-phase four-wire, 50 Hz or 60 Hz
The system is fair to all high-speed power line transmission technologies Easy implementation, minimum cost increase Band-assured system, best-effort system
The system complies with standards, and related legislation of each country EMC-related legislation (FCC Part 15) PSD mask, etc.
3. The system can be utilized worldwide
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Coexistence Requirement and the Solution
Analysis of system requirements– Categorization application areas
Definition of requirements for system specification– Basic system requirements– Requirements from CE manufacturers– Other system requirements
CEPCA solution– Specification for coexistence system – Summary
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CEPCA SolutionNecessary technology analysis for coexistence of PLCs with different systems
Collision avoidance method among different systems
Time Division (TDM)
Frequency Division (FDM)
Filter (+) unnecessary (-) necessary
Synchronization of systems (-) necessary (+) unnecessary
QoS (latency vs. efficiency) (-) some overhead (+) exclusive useTolerance for frequency
selectivity (+) high (-) low
Common signal among different systems - Requirements
• Easy implementation (Fair among different systems)• Coverage (Equivalent to or above PLC modem)• Transmission efficiency (Little loss for bands)
Items compared
Avoidance method
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CEPCA Solution
Collision Avoidance Method Between Different Systems
FDM/TDM hybrid
In-home systems use all bands if there is no Access system
In-home systems coexist with FDM, opening frequency band if there is Access system
– Assures independency of Access system
In-home systems avoid collision with TDM
– Precise band-sharing is possible
time
freq
In-HomeIn-HomeIn-Homeme
Access Access
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CEPCA Solution
System Synchronization in TDM
Utilization of AC zero-cross point
Common standard for PLCs of different systems
High reliability, eliminating synchronization lag by clock error
time
Sync Point
time
freq
In-HomeIn-Home In-Homeme
Access Access Access
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CEPCA Solution
TDM/FDM Format
time
freq
In-HomeIn-Homeme
Access Access Access
Best Effort slot TDMA slot
In-Home
TDM_UNIT_LEN
system 1 system 2
time
freq
In-HomeIn-Home In-Homeme
ch #x
ch #y
TH
TA
TDM_UNIT_LEN
TDM UnitCDCF Window of In-Home systems
CDCF Window of Access system D-Slot S-Slot 2S-Slot 1 S-Slot 4S-Slot 3FDM channel
Access Access Access
Programmable
Fine-TDM: Static slot (S-Slot) and Dynamic slot (D-Slot) Realizes band assurance and band adjustment Handles burst-like traffic with D-Slot alone
Programmable FDM: 2MHz step size for FDM boundary Flexibly handles area differences and future legislation
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CEPCA Solution
Common Signals Among Different Systems
System A
System B
System C
Band assignment among systems with CDCF*
Band assignment in each system
CDCF: Commonly Distributed Coordination Function
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CEPCA Solution
Composition of CDCF Signals
CDCF Signal
time
Sync Point
A: Access indicates its existenceH: In-Homes indicate their existenceJ : Request for joinB: D-slots for Best-effort traffic
BbBa BcA H2H1 Jr JpH4H3
Access systems existence indication, indicate FDM/TDM mode
Time slot indication in using in-home systems
Use-request indication of in-home systems (with priority)
D-Slot use-request indication
Transmission of information by with/without OFDM signalDefines slot, based on AC zero-crossRegards it as in-band signal, and realizes coverage equivalent to or above the
modem using common hardware
#x
#y
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CEPCA Solution
Summary
Collision avoidance mechanism of TDM/FDM hybrid
Wide-range coexistence is realized with the combination of flexible TDM which doesn’t need filter and frequency-occupying FDM
Fine TDM with “D-slot”– QoS is handled flexibly with parallel use of fixed slot and
variable slot– Band-assured fixed slot (S-Slot) with priority
Programmable FDM– Area differences and future legislation are flexibly handled.
Common coexistence signal among different systems (CDCF)
– Uses same band with PLC modem
– Realizes coverage equivalent to or above the modem and part-sharing
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Approach to Standardization
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Members: Include 7 promoting companies and 1 contributing company27 members (21 from Japan, 3 from US, 3 from EU)
Activity: Started July, 2005; 30 meetings held to date
Technical Work Group—Standardization Activity
Accomplishments:• Created coexistence technology specification• Contribute to standardization activities
Joined IEEE P1901 WG (8 Entities), and proposed:– Use Cases– Features / technology requirements for coexistence
Joined ETSI PLT (2 Entities), and proposed:– Technology requirements for coexistence– Concept of coexistence specification
Future Plans:• Create certification specification and document an
certification system• Propose coexistence technology specification to IEEE
and ETSI PLT
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CEPCA
Members wanted! Visit http://www.cepca.org/ for details
Thank you!
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