katsuyuki kariya † , tatsuya nakamura † , shinji takeuchi † , atsushi otogawa †

Frankfurt (Germany), 6-9 June 2011

Katsuyuki KARIYA†,

Tatsuya NAKAMURA†, Shinji TAKEUCHI†, Atsushi OTOGAWA†

Yukio IWASHIMA††, Yasuhisa MATSUSHITA††

Hitoshi KUBOTA†††, Toshihiro INOUE†††

† : Chubu Electric Power Co., Inc.,†† : ChubuSeiki Co., Ltd.,

††† : Mitshubishi Electric Corporation

Katsuyuki KARIYA – Japan – Distribution network business activities and impact of regulation – 0737

Investigationof

Wireless Telecommunication for AMI


Introduction Measured wireless media Conditions of measurements Results of the Investigation Summary

Outline



Why Advanced Metering Infrastructure (AMI)?

Improves efficiency of meter reading Energy conservation

Future; Efficient operation of power distribution under condition in which distributed power source are widely spread, etc

Introduction



SM

SMN

WAN

Server Computers

GW

What’s Advanced Metering Infrastructure (AMI)?

A Model of AMI System

Introduction

Millions of smart meters (SMs) perform two-way communication with Server computer via smart meter networks(SMNs), Gateways (GWs), and Wide area network (WAN).



Why wireless telecommunication? Number of meters per service transformer is

small (About 10~20 meters) Meters are installed outside

Introduction


The installation cost of the PLC coupler is expensive in Japan.Therefore, the wireless is more cost effective .


Introduction

Radio propagation characteristics of three kinds of license free wireless communication media were investigated.

What's suitable wireless media for AMI system? Easy to use Low cost

License Free Wireless media in Japan •2.4GHz wireless LAN•950MHz Low Power Radio•429MHz Low Power Radio



Measured wireless media2.4GHz

Wireless LAN

950MHz

Low Power Radio

429MHz

Low Power Radio

Output Power 10mW/MHz 10mW 10mW

Channel Band Width

22MHz 200kHz 8.5kHz

Modulation DSSS*1 GFSK*2 GFSK*2

Data Transfer Rate

1Mbps 100kbps 4.8kbps

Reference IEEE 802.11b

ARIB*3 STD-T33

ARIB STD-T96 ARIB STD T-67

*1 : Direct Sequence Spread Spectrum*2 : Gaussian Frequency Shift Keying*3 : Association of Radio Industry BusinessKatsuyuki KARIYA – Japan

– Distribution network business activities and impact of regulation – 0737


Measurements excecuted under condition which simmulated communication

A) Between a GW placed on a utility pole and SMs of detached houses.

B) Between a GW placed on a utility pole and SMs in pipe shafts of an apartment building.

C) Among SMs in pipe shafts of an apartment.

Conditions of Measurements




A transmitter was placed on a handrail of outside stairs of an apartment building.

Receivers were placed by utility poles around the apartment building.

A) Communication between GW and SM of detached house

6m1.8m

ReceiverTransmitterKatsuyuki KARIYA – Japan – Distribution network business activities and impact of regulation – 0737



A transmitter was placed in a pipe shaft of an apartment building.

Receivers were placed by utility poles around the apartment building.

B) Communication between GW and SM in Apartment Building

1.8m

Transmitter ReceiverPipe ShaftKatsuyuki KARIYA – Japan – Distribution network business activities and impact of regulation – 0737



Both transmitter and receivers were placed in pipe shafts of an apartment building.

C) Communication among SMs in an Apartment Building

Transmitter & Receiver



Results of measurements

0

10

20

30

40

50

60

70

80

90

100

- 120 - 115 - 110 - 105 - 100 - 95 - 90 - 85 - 80 - 75 - 70 - 65 - 60 - 55 - 50

Received Signal Power [dBm]

Pac

ket

Erro

r Rat

e [%

]

2.4GHz wireless LAN Received Signal Power vs. Packet Error Rate

Received Signal Power vs. Packet Error rateServiceable areaWhere received signal power is strong enough and packet error hardly occurs.

Fringe areaWhere packet error increases

Unserviceable areaReceived signal power is so weak that packet error frequently occurs.




Serviceable Area Fringe Area Unserviceable Area

Wireless LAN Received Power >= -85dBm

-85dBm> Received Power

>= -98dBm


950MHz Low Power Radio

Received Power >= -95dBm


>= -100dBm


429MHz Low Power Radio

Received Power >= -90dBm


>= -110dBm


Classification of measurements Results



100m

200m

0°

180°

90°

270°100m

200m

0°

180°

90°

270°


(a)2.4GHz Wireless LAN

A)Communication between GW and SM of detached house(1)


100m

200m

0°

180°

90°

270°

Clear SpaceReinforced Concrete Building

Unserviceable AreaFringe AreaServiceable Area

(c)429MHz Low Power Radio(b)950MHz Low Power Radio


950MHz low power radio had longest range in the three wireless media.

All of the three wireless media had difficulty to establish communication across the apartment building nearby.

Results of measurementsA)Communication between GW and SM of detached house(2)



30m

0°

90°

180°

270°

30m

0°

180°

90°

270°

30m

0°

180°

90°

270°


(c)429MHz Low Power Radio(b)950MHz Low Power Radio(a)2.4GHz Wireless LAN

B)Communication between GW and SM in Apartment Building(1)


Clear SpaceReinforced Concrete Building

Unserviceable AreaFringe AreaServiceable Area


429MHz low power radio could establish communication between inside of a pipe shaft and utility poles on both steel door’s side and its opposite side of the pipe shaft.

2.4GHz wireless LAN and 950MHz low power radio had difficulty in communication between SM and GW on a steel door’s side of the pipe shaft.

Results of measurementsB)Communication between GW and SM in Apartment Building(2)




8m8m 16m 16m

2m 1m6m2m

Pipe Shafts

Staircase

Dimensions of the Apartment Building.

(5-storied building)

C) Communication among SMs in Apartment Building(1)


Chose an apartment building which has long distance between each pipe shafts.



(c)429MHz Low Power radio (a)2.4GHz Wireless LAN (b)950MHz Low Power radio

C)Communication among SMs in Apartment Building(2)


Good communication even with adjacent pipe shaft

Poor communication with adjacent pipe shafts

Staircase Staircase Staircase

Room105

Room505

Tx

Room504

Room103

Room404

Room405

Room304

Room305

Room204

Room205

Room104

Room501

Room401

Room301

Room201

Room302

Room303

Room202

Room203

Room502

Room503

Room402

Room403

Room505

Room405

Room305

Room205

Room105

Room101

Room101


Room303

Room103

Room304

Room305

Room204

Room205

Room104

Room501

Room502

Room503

Room505

Room301

Room201

Room101

Room504

Room404

Room402

Room403

Tx

Room105

Room505

Room405

Room305

Room205

Room405

Room105

Room202

Room203

Room101

Room302

Room401


Room105

Room505

Room405

Room305

Room205

Room101

Room504

Room505

Room404

Room405

Room105

Room201

Room101

Room502

Room503

Room402

Room403

Room302

Room303

Room202

Room203

Room501

Room401

Room301

Room103

Room204

Room205

Room104

Room304

Room305

Tx

Unserviceable AreaFringe AreaServiceable Area Tx Transmitter


429MHz low power radio could establish communication not only between SMs in same pipe shaft or between SMs in adjacent pipe shafts on same floor but also between SMs in adjacent pipe shafts on different floors.

Results of measurementsC)Communication among SMs in Apartment Building(3)



In view of serviceable area 950MHz low power radio is the most suitable communication media for smart meter network.

429MHz low power radio has advantages over two other wireless media for communication in apartment buildings.

Summary



The results of this investigation shows differences of radio propagation characteristics among wireless media.

Steady SMN must be built with selecting suitable wireless media for conditions of meter installation.

Summary



Thank you for your attention.

We Japanese are grateful for the kindness of people of all over the world.


katsuyuki kariya † , tatsuya nakamura † , shinji takeuchi † , atsushi otogawa †

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