Power Line Communications

Outline Power Line Characteristics Power Line Applications: Broadband Narrowband Bridging PLC and Wireless Adaptive Backoff Algorithm

Power Line characteristics Wired communications, but: Frequently changing environment Narrow band noise (Jamming) Burst noise Various attenuation (loads on power outlets) Random access Multihop (hidden nodes) Very similar to wireless environment 3

FCC and CENELEC Band Allocations North American Band Regulations Prohibited General use 100 kHz 200 kHz 300 kHz 400 kHz 500 kHz 600 kHz 700 kHz 800 kHz CENELEC Band Regulations “A” “B” “C” “D” Prohibited Consumer Use with Protocol Consumer Use with No Protocol Electricity Suppliers Electricity Suppliers And Their Licensees Consumer Use No Protocol 20 kHz 40 kHz 60 kHz 80 kHz 100 kHz 120 kHz 140 kHz 160 kHz US (FCC: 100-400kHz) Japan (ARIB, MPT: 20-80kHz) European Outdoor (CENELEC A, 18-90kHz) European Outdoor (CENELEC A+, 70-95kHz) European Indoor (CENELEC B, 95-125kHz)

Principles of DCSK Modulator Operation Spread spectrum technology - provides maximal spectral diversity, handles notches and narrow band noise. Phase Shift DCSK Modulator 0010 Encoded Bits Basic Symbol

Broadband market

Internet Distribution PLC – Wireless adapter

Command & Control Market

“Smart Grid” AMR/AMM/AMI

Utilities and PLC ? The increase in public demand for energy creates the need for Energy Saving and Energy Management procedures. Utilities can lower cost by reading meters remotely, charging according to time of use or according to level of power used, automating power failure recovery and lowering the investments in new power stations. Utilities can increase revenue by offering more services to the customers (besides just offering power). In some areas of the world, 30% and more of the electricity is stolen. AMR/AMM is used to detect electricity looting. The worldwide potential market for Automatic Meter Reading (AMR) is more than 1B meters. Almost EVERY power utility in the world is under pilots or trials to use AMR.

What is AMR? (Automatic Meter Reading) Definition: The technology of automatically collecting data from Water, Electricity or Gas metering devices and transferring that data to a central database for billing and/or analyzing. Billing is based on actual consumption rather than an estimate based on previous consumption, giving customers better control of their use of electric energy, gas usage, or water consumption. AMR technologies include handheld, mobile and network technologies based on telephony platforms (wired and wireless), radio frequency, or Powerline Communication (PLC) 11

What are AMM & AMI? (Automatic Meter Infrastructure, Automatic Meter Management) Definition: These are an improvement on AMR and therefore include more options. The main different is that AMM/AMI systems allow two-way communication, which means it is not only meters reading but also meters control, sending pricing information to the meter as well as disconnection command etc. It Refers to systems that measure, collect and analyze energy usage from advanced devices such as Electricity meters, Gas meters, and/or Water meters, through various communication media on request or on a pre-defined schedule. This infrastructure includes hardware, software, communications, customer associated systems and meter data management software.

Applications: AMM/AMR/AMI A network between measurement devices (meters) and business systems to allow collection and distribution of information to customers, suppliers, utility companies and service providers. Customer Smart meter Utility Company AMM/AMR/AMI enables Homes and Businesses to participate in, or provide, demand response solutions, products and services. A two way communication system for meter reading and command/control – with the ability to signal increase of price as a result of high power demand, disconnect if there is fraud or non-payment and allows for Energy Management in the home and use the meter as a gateway to the home. By providing information to customers, the system assists a change in energy usage from their normal consumption patterns.

Demand Response: Existing power lines are used for two-way communication between different parts of the system Higher price indication, encourages consumers to reduce demand, thereby reduce the peak demand for electricity.

Benefits AMR/AMM/AMI Revenue Operation & Distribution More accurate billing with shorter cycles Tamper warnings and identification Load limits, remote disconnect Customer Service More informed usage Reduce volume of calls Operation & Distribution Detects and responds to power outages Asset loading & optimization Emergency load shedding Demand Management Pricing based on time of day Energy profiling and analysis (online) Load control tools By 2013, 28% of electric meters worldwide are expected to be “smart.” (ABIresearch study)

Street Light Control Saving 40% in electricity bill by replacing the Analog Ballast into an electronic Ballast with PLC Lower power consumption Dimming Maintenance

Smart Home Basics Remote security, fire and health monitoring Appliances Remote Diagnostic Turn on/off lights and appliances remotely Message sent to raise/lower AC via PLC Lower thermostat remotely during high tariff periods Remote Meter Reading And Peak Demand Response

Smart Home – cont’ Main stopper for Smart Home deployment – interoperability issues Approach: Defining the common “language” between all home appliances Known protocols: ZigBee UPnP (Universal Plug & Play) SCP (Simple Control Protocol) HomePlug

Bridging PLC and Wireless

Adaptive Backoff Algorithm The overhead of a backoff algorithm is a combination of the silence period and of the corrupted transmissions due to collisions Conventional CSMA/CA adapts to the load by increasing the contention window AFTER the collisions (exponential backoff) The IT800 backoff algorithm changes the contention window size to match the estimated current load BEFORE the collisions.

Adaptive Backoff Algorithm - cont Each node estimates the load ON RECEIVENG of the data frame Each data frame header contains the information of the CW size, and the randomized backoff value Backoff value/CW ratio provides an indicator of the load – the smaller the result is, the load is higher The next CW is increased if the load grows