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Internet MeteringIntroduction
Contents: Introduction Hopes Facts Obstacles Solutions Summary
Harold Hayes, Product ManagerI+C MetersLandis+Gyr Africa
Internet
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Introduction
The mobile communication and the Internet are technologies and markets, which are determined through a high dynamic. The assembling of the two subjects causes even higher expectations. Not only new services and applications, but also complete new business areas will be developed over the next few years.
In the practise the fulfilment of the expectations has been seen as not unproblematic. The transmission in the wireless environment is determined through low bandwidth, higher delay times, fundamental smaller reliability and high security needs. According to the situation the technologies as TCP and Internet applications have to be adapted.
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Hopes
Standard Internet technology is available and can be used for metering
GPRS/Ethernet: Is always connected and the technology is cheap
GPRS/Ethernet: Reduced communication costs
Faster read out times
New applications
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Facts
GPRS and Ethernet offers low-cost access to the Internet via TCP
Internet technologies are supported by the utility‘s IT-departments
PSTN modem banks are supported by the meter reading department
Existing infrastructure (Central station, LAN, meters etc.) can be upgraded to Internet Metering
Online monitoring
Ethernet replaces telephone lines in I+C buildings
Enabler as world wide energy data provider
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Communication CostsCalculation example
Typical application:
Daily read-out time of 6 energy load profiles, TM=15min
Typical system:
Typical system parameters:
GSM read out time: 72s (via dlms)
GPRS data size: 10kByte
GSM/GPRSNetwork
Central station Meter
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Communication CostsCalculation example
Tariffication model:
Provider, Vodacom SAhttp://www.vodacom.co.za
GSM: R0.99/min
GPRS: R0.02/10kByte
Typical data size per day:
Data (HDLC) per day: 6.2kByte
TCP overhead per day: 2.8kByte
Heart beats (HDLC) for 5 hours: 1.0kByte
Total: 10kByte
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Communication CostsCalculation example
GSM Fix cost per year:
= 12*R 1490/month talk 1000
Variable cost per year:R433 = 72s*R 0. 0165 /Sec *365days/year
GPRS Fix cost per year:
12*R 1490/month talk 1000
Variable cost per year:R 73 =10kByte*R 0.02 /10kByte *365days/year
Cost saving per meter per year:R 360.62
Communication cost = f (Tariffication model, Data size)
R 360.62 * 5000 meters R 1.8 million per year
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Solution: Internet Meter Gateway
Solution set: Internet Meter Gateway, VPN, Data encryption
Obstacles
Addressing: The meter cannot be addressed from the Internet:Shortage of IP addresses, Security.
System integration: Existing data acquisition systems do not accept access from the internet: Security, Scheduler based processes.
Unauthorized meter access Unauthorized changes to parameters or software in the meter Virus attacks to meter Data fraud Technology Lifetime: Internet -> 3 years, Metering -> 15
years
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The Internet Meter Gateway Solution 1/2
Central Station
COM1
COM2
...
PSTNNetworkInternet
Gateway
= Replacing the modem bank
Virtual Comports
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The Internet Meter Gateway Solution 2/2
Central Station
COM1
COM2
...
PSTNNetworkInternet
= System Security
DMZ
Gateway
F i r
e w
a l l
F i r
e w
a l l
Meter gate guard
Internet Meter Gateway in combination with the communication unit controls and restricts the access to the meter
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How does the system work?
GRPS
privateGSM-Network
(e.g. Swisscom)
Internet
Central
Internet Meter Gateway
Intranet
Fix IP Address
Virtual Com Port connectio
n
Ethernet
Dynamic IP Addressing
2. Dynamic IP
Addressing
3. Subscribe to iMEGA
Meter x
4. Dial (ATDT...) via ComPort Dial
Meter x5. Meter Connected to central
1. Login to Network Pre-Settings
Fix IP address connects central
to iMEGA
IP Address of iMEGA and
Identifier
Fix IP Address connects iMEGA to
LAN/Internet
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System migrationat central side
Migration cases: Communication technology: GSM, PSTN GPRS,
Ethernet Call process: central calls meter meter calls central Processing: sequential processing parallel processing
Implementation task: Installation of virtual modems
(Existing physical modems may remain) Installation of an Internet Meter Gateway in DMZ
Central station requirement Support of high communication delay times
At central station no conception change needed.
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Data acquisition timesSequential versus parallel
Sequential data acquisition by using PSTN/GSM technology
Parallel data acquisition by using GPRS/Ethernet technology
M1 M2 M3 M4 M5 Mn+1
M1
M2
M3
M4
M5
Mn
Time saving compared to PSTN/GSM technology
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Security at meter sideData encryption
Internet
001011010001001001010010100101010010010100101010101010101010101010010101010101010100100101010101100101001010
001011010001001001010010100101010010010100101010101010101010101010010101010101010100100101010101100101001010
Metering Company
Market Participant
001011010001001001010010100101010010010100101010101010101010101010010101010101010100100101010101100101001010
Signature Algorithm:Elliptic Curve (ECDSA) ISO/IEC 5946-1/2/3, ISO/IEC 7816
Key Length:192 Bit corresponding to RSA 1280 Bits
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SummaryOpportunities with Internet Metering
A wireless connection (GPRS) or a connection via LAN (Ethernet Local Area Network) to the Internet is conveniently possible with TCP/IP.
Existing infrastructures such as central stations, LAN, meters, etc. can continue in use. The installation and maintenance costs are reduced, however, since for example no further central station modems are required.
Parallel data acquisition results in shorter acquisition times. With TCP/IP the meters can be permanently connected to the
central station to permit continuous monitoring of the meters. Nevertheless the communication costs with GPRS are significantly lower than with normal GSM mobile communication.
Worldwide Internet access and lower communication costs (there are also no roaming costs for connections abroad) make new applications possible, e.g. worldwide energy data providers.
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