Low Frequency Narrowband PLC for Neighborhood Area Networks

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Low Frequency Narrowband PLC for Neighborhood
Area Networks

• Shakti Prasad Shenoy, Ph. D
• Architect, Smart Home and Energy
• NXP Semiconductors India, Bangalore

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Presentation Outline

• Communication and Networking Requirements for
  Automatic Metering Networks (AMN)
• Narrowband Power Line Communications (NB-PLC) for
  AMN
• NXPs PLC solution NPC1100

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Communication Challenges Unique to AMN

• Quality of Service (QoS) requirements and load
  patterns significantly different from typical
  mobile voice/data network
• Network planning and optimization important.
• Need for Self Organizing Network supporting
  communications route discovery, connection
  establishment and maintenance to provide the
  performance guarantees required by metering
  applications.
• Protection of metered data against unauthorized
  access a key requirement for both consumers and
  utilities
• Non-repudiation Provides proof of the integrity
  and origin of data. An authentication that can be
  asserted as genuine with high degree of certainty
• Comprehensive specification of AMI security
  requirements in AMI System Security
  Requirements. Technical Report, AMI-SEC TF,
  OpenSG, December 2008

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Network Requirements for AMN

• Related concept Types of data
• Various data-time combinations
• Device need not send all data that it has logged.
  Utilities will require additional data only from
  time to time for forecasting and/or analysis
• Data logged and its (large) size useful only for
  analysis. Outage, failure chain, event timings
  etc
• Aperiodic, highly useful, bulk data transfer.
  Need to account this
• Do you want ACKS for all your messages
• Emerging security standards require security
  level that adds to data traffic on network
• Standards like ZigBee have message traffic which
  is more than 75 security overhead
• Network reuse
• Reuse network for DR or Direct Load Control ?

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Approach to set up AMN

• Clear objectives. Decide on what do you want to
  achieve with the AMN
• Set measurement metrics pre/post deployment
• Use case driven analysis
• Identify/Research use cases
• Derive quantifiable technical requirements like
  network capacity, reliability and coverage
• Account for future requirements
• Objective evaluation of communication
  technologies
• Phased rollout
• Business reasons
• You will never get it first time right. Live with
  it!
• Interoperability is a time consuming/iterative
  process even when meticulously planned. Know it
  and account for it

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Typical Smart Metering Use Cases

• Multi-interval reading Meter reading frequency
  configured by utility
• Each interval data consists of sub-units of finer
  time readings
• Downstream Command approx 25 bytes
• Upstream Periodic reports approx 2.5k bytes
• On demand reading Meter expected to send reading
  in lt 5 sec on command from utility
• Downstream Command approx 25 bytes
• Upstream Meter data approx 100 bytes
• Firmware upgrade
• More during initial network setup and then 1 or 2
  updates a year
• Downstream Upgrade anywhere between 0.5K to 2M
  bytes
• Upstream ACK and associated data upto 100 bytes

Data source SG Network Requirement
Specifications V5.1, Open SG
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Requirements Based on Example Use Cases

• Multi-interval reading
• Measurement Interval approx 5 per day
• Message Latency max 4hrs
• Reliability min 98
• On-demand reading
• Measurement Interval 25 per 1000 meters per day
• Message Latency max 5 sec
• Reliability min 98
• Real time pricing
• Measurement Interval 60 per 1000 meters per day
  each for Real-time pricing, Critical Peak Pricing
  and Time of Use
• Message Latency max 5 sec
• Reliability min 98

Data source SG Network Requirement
Specifications V5.1, Open SG
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Derived Network Requirements

• Assuming urban device density of 2000 meters/km2
  and rural device density of 10 meters/km2
• Example data capacity requirement for metering
  around 7.2 Mb/hr per 1000 meters
• The network should support message latency of 3
  seconds for smart meter operations
• Message delivery reliability as low as 98 should
  be supported
• Security overheads and requirements extra

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Power line communications (PLC)

• Key drivers for PLC
• Deployment costs comparable to wireless
• High connectivity and extensive coverage
• Scalability Simply add another PLC transceiver
• Reliability through redundant communication
  channel
• Ultra-Narrow Band (UNB) 0.3-3 kHz
• Very low data rate (about 100 bps)
• Large operational range (150km or more)
• Mature technology but usually proprietary
• Narrow-Band (NB) 3-500kHz
• Single carrier Home and building automation (low
  data rate)
• OFDM based NAN and Home automation. Data rates
  close to 1 Mbps
• Broadband (BB) 1.8-250MHz
• Data rates of several Mbps

Source S. Galli, A. Scaglione, and Z. Wang, For
the grid and through the grid The role of power
line communications in the smart grid, Proc.
IEEE, vol. 99, no. 6, pp. 9981027, 2011
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Worldwide NB-PLC Bands

• EU CENELEC 3-148.5 kHz over LV in Europe
• A band 3-95 kHz, reserved to power utilities.
• B band 95-125 kHz, any application.
• C band 125-140 kHz, in home networking systems
• Regulated. Mandatory CSMA/CA protocol
• D band 140-148,5 kHz, alarm and security
  systems.
• USA FCC 10-490 kHz for general supervision for
  an electric public utility
• Japan ARIB 10-450 kHz
• China CEPRI 3-500 kHz
• India ? ISGF has a role to play

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Major Drivers for OFDM based NB-PLC

• Optimized for Smart Grid and home automation
• Addresses both access (LV/MV lines) and in-home
  applications
• More robust to channel impairments and noise
• No antennas required
• Communication possible in extremely hostile
  environment where other access technologies may
  fail
• Metal shielded cases
• Underground installations
• No requirement of GIS
• Side steps the issue of health concerns that may
  be faced by wireless technologies

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PLC Performance w.r.t Use Cases

• Data rates supported
• Tens to several 100 Kbps
• Message delivery latency
• lt 1 s
• Coverage
• Order of kms
• Data rate dependent on distance
• Can be solved using relays/repeaters
• Reliability
• Depends on the power line on which it is
  installed

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Standardization of OFDM Based NB-PLC

• Initial drive by industry alliances
• G3-PLC Aliances (ERDF, Maxim et. al)
• PRIME (Iberdrola et. al)
• International Standardization bodies step in
• ITU-T G.hnem
• IEEE P1901.2
• Active participation by G3-PLC and PRIME Alliance
• Coexistence between ITU-T and IEEE standards a
  key factor
• Efforts are on towards coexistence
• Details yet to be worked out

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Data Rates of Various NB-PLC Standards
Parameter Parameter PRIME G3-PLC IEEE P1901.2 G.hnem
Frequency Range CEN A (kHz) 42 - 89 35.9 - 90.6 35.9 - 90.6 35.9 - 90.6
Frequency Range FCC (kHz) X 159.4 - 478.1 35.9 - 478.5 35.9 - 478.1
Max Data Rate CEN A (kbps) 61.4/123 45 52.3 101.3
Max Data Rate FCC (kbps) X 207.6 203.2/207.6 821.1
Source Local Utility Powerline Communications in
the 3-500 kHz Band Channel Impairments, Noise,
and Standards. Marcel Nassar et. al, IEEE Sig.
Proc. Magazine (to appear)
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Need for multi-standard solution

• Different standards operate under different
  assumptions on channels
• Different channel delay spread assumptions
• Different assumptions on powerline noise
• Different coding and modulation strategies
• Different symbol/frame lengths
• Utilities have their own requirements and
  constraints
• Ground realities
• Complexity
• Cost
• Features
• Robustness
• Different countries opting for different
  standards
• Multi-standard solution retains the benefit of
  scale

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NXP focus on Smart Home and Energy

• NXP is a global leader in high performance mixed
  signal semiconductors with a very broad portfolio
  of product and solutions.
• Smart Energy is one of the focus applications of
  NXP
• NXP has a wide coverage of technologies used in
  smart grids and home/building energy management
• NXP is combining technologies from different
  business units to create innovative solutions for
  the smart grid
• By bringing various technologies to the same
  process node, NXP is enabling an integration
  roadmap to improve performance and lower system
  cost
• NXP is a member of ITU-T , IEEE P1901.2, IEEE
  802.15, G3 Alliance and PRIME and ZigBee Alliance

NXP Bangalore is a major RD center for its Smart
Home and Energy Product Line
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NXP Smart Energy Capability
Communication
Billing Meters Gateways

• OFDM Multi-standard PLC
• 802.15.4 (ZigBee, 6LowPAN, JenNet)
• Wireless M-bus

• ARM7/9, Cortex M0/M3/M4 MCUs
• Analog Front-End
• RTCs
• GreenChip SMPS solutions
• Display Drivers
• Standard ICs

Non-Billing Metering
Smart Grid Security

• Energy Metering ICs
• One Chip Wireless Zigbee Meter
• Embedded power monitoring for appliance

• End-to-end security authentication

Payment

• Contact card readers
• Contactless card readers
• NFC Payment

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NPC1100 (1/2)

• Flexible solution for smart metering
• Multi-standard OFDM
• PRIME
• G3-PLC
• ITU-T G.hnem
• IEEE P1901.2
• Security/Crypto primitives for Secure Services
• Embedded application processor available for
  customer programming.
• Cortex M3 at 128 MHz
• M3 can run both the PLC stack as well as
  application program
• External Flash for application program and
  firmware
• IC will be delivered including PLC protocol stack

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NPC1100 (2/2)

• Flexible OFDM engine
• Data rates up to 1 Mbps
• Regulation compliant CENELEC/FCC
• Freely configurable bandplans
• On-chip Analog Front End
• 123 dB input dynamic range
• 60-70 dB output dynamic range
• Real Time Clock
• Multiple standards via firmware

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Functional Blocks of NPC1100

• 128 MHz Cortex M3
• 50 for MAC layer

• Interfacing
• UART, I2C
• External SDRAM
• GPIO

Designed for power efficiency

• Security
• AES
• Key management

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Meter Application
L1
L2
L3
N
Meter Chip
EEPROM
Metrology frontend
LCD
NPC1100
400V
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Low-Cost SE1.x IPD Reference Design
Available

• Standard Plastics and LCD
• Custom PCB design
• Daughter boardfor antenna and switches
• Shows
• Display kW, Cost, Time,Temperature
• kWh and CO2

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Load Control Device Smart Plug
Available
The Load Control Device uses the
following Clusters to implement an Smart Plug
- Key Establishment - Client Server DR /
Load Control - Client Price -
Client Time - Client

• The Load Control and Demand Response device
  supports following features
• Remote device turn-off to protect the grid from
  overload
• On/Off based on pricing information from the
  utility
• Load Control Opt-In / Opt-Out support
• Energy consumption measurement

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ZigBee SE 1.x Load Control and Non-billing
Metering
Available
ZigBee Smart Plug Application Note EM773
Metrology S/W and H/W integrated to JN5148 JN5148
Module replaced with JN5148 chip with 20dBm
output USB transceiver with LPC1343 and JN5148
ZigBee SE1.x USB Adapter
ZigBee SE1.xCommunication
Single ChipIntegration!
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Contact NXP

• For more information, please feel free to contact
  
• Janakiram Annam (janakiram.anna_at_nxp.com)
• Director of Engineering
• Product Line Smart Home Energy
• Stefan De Troch (stefan.de.troch_at_nxp.com)
• Director, International Product  Marketing
  Manager Smart Energy
• Product Line Smart Home Energy

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Questions?
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Backup slides
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Network Requirements for AMN

• Network topologies and architecture
• What aligns best with grid topology and
  requirements? Star, Tree, Hybrid, Mesh?
• Scalability
• Network entry and provisioning. (Has security
  implications as well)
• Does device replacement lead to reconfiguration?
  Time required, effect on AMN
• Communication functionalities of device types.
• Meters/Leaf nodes, Routers, Concentrators,
  Aggregators
• Data latencies revisited. Questions to ask
• What is the end-to-end data latency requirement
  from WAN to AMN?
• How asymmetric are data latencies for
  downstream/upstream traffic?
• Once you have data, then what? Act! Latency on
  these actions impacted by traffic level on
  communications network.
• Need to give operators timely data and time for
  them to act on it. Analyze who needs what, when,
  and how much time to act/decide

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Security/Crypto unit

• AES 128/192/256 bits encoding/decoding
• Key management system
• OTP 256 bits
• MAC address
• Unique keys (availability TBD)

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Software architecture NPC1100
Application Layer
Typical software architecture Communication stack
MAC Layer
PHY Layer
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Software architecture NPC1100
Application Layer
Cortex M3 core library
MAC Layer
PHY Layer
Closed DSP core firmware
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Software architecture NPC1100
Customer writes software on ARM cortex M3 using
proven ARM development environment
Application Layer
Cortex M3 core library
MAC Layer
PHY Layer
Closed DSP core firmware
Library and firmware are paired per PLC standard
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Software deliveries

• SDK
• Microkernel nuttX 5.19
• Delivered tools/libraries with reference kit
• Libraries for the PLC stack on the Arm Cortex M3
• Firmware for download onto the NPC1100 hardware
• Diagnostics application on top of the PLC stack
• Example application to build a small PLC network
  in a lab
• Other
• Documentation about API
• Application notes, white paper, system guidelines

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Reference kit

• Dedicated application board with NPC1100
• Functionality
• Example application to setup communication in a
  small electricity network
• Single or three phase electricity connection
• Two kind of nodes
• Network management node (limited functionality)
• Network leaf node (functionality with full PLC
  protocol)
• Communication to application board
• UART
• Ethernet

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NXPs Supported ZigBee Profiles Overview

• ZigBee Smart Energy
• Devices are directly connected to a Smart Grid
• Networks are utility managed, but may be customer
  property
• Ideal suitable for Smart metering solutions, Data
  Concentrators any metering measurements
• ZigBee Home Automation
• Broad range of devices for consumer homes defined
• Commissioning a bit complex for non-technical
  consumers
• Ideal for Smart Homes controlling door locks,
  Security, HVAC, etc..
• ZigBee Light Link
• Profile defined to support lighting only ease
  of use and installation has been the focus
• It is not designed for professional installation
  throughout a building
• Ideal for residential industrial wireless
  lighting infrastructure solutions
• ZigBee RF4CE
• RF for Consumer Electronics
• Small stack size and focussed on AV industry it
  is all about low cost
• Ideal for Setup-Box, RF based Universal remote
  controls Virtual Remotes through iOS / Andriod
  apps

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NXPs ZigBee Solutions
Description Pros Cons
Split ARM Transceiver Stack supplied as libraries for customer to link with Profiles a mixture of source and libraries Transceiver runs MAC only Cost effective flash and RAM Enough RAM to run coordinator with multiple open TLS connections Lots of application space for customer app. ARM tool chain for development and debugging facilities Range of OSs and tools supported RAM/Flash extendable Re-use existing ARM code Two chip solution, so higher BOM cost
Split Arm 256kB Flash/32kBRAM CPUTransceiver Arm processor running customer app. NXP chip running stack Self contained binary means customer doesn't need to compile / port code to their hardware. Customers can get started easily and with minimum support whatever their hardware platform. Difficult o run a full function coordinator in this way (ESI-Meter)
System On Chip Single chip solution with customer app running on our processor Lowest cost Only suitable for the smallest applications as most flash /ram consumed by stack and profiles
LPC17xx
JN5161
JN5168
JN6168
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Home Energy Application Note JN-AN-1135
Available
Smart Energy Profile In Premise display
application note. The Evaluation kit sensor board
is the SE Metering Device, and the Controller
Board is the IPD
The Application note uses the following Clusters
to implement the Home Energy Monitor Key
Establishment Simple Metering Price Time
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Energy Monitoring Screen
Available
Time Cluster to synchronise time with meter
Battery Level Indicator using JN5148 on-chip
battery monitor
Power bar shows instant energy consumption
Instant energy consumption and current tariff
Signal Strength Indication
Mode button allows user to toggle Between KwH,
Price and CO2
Configuration Info
Consumption History
Pricing Information
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Price History Screens
Available
Price Screen Price is unit price in the selected
currency (Set Up Menu) Start Time and Duration H,
M and L is the Pricing Tier High Medium and
Low History Screen Displays daily historical
data Details energy consumed per pricing tier