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Transcript Wireless Ethernet ()

Industrial Wireless Ethernet
The New Era of Data Transmission
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OSI Layers
Open Systems Interconnection
(OSI) is a standard reference
model for communication
between two end users in a
network
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Ethernet communications is made up
using these layers.
Data from the application layer i.e. File
transfer or DCS etc. is wrapped up inside
all of the other layers
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Types of Spread Spectrum for Ethernet

Direct Sequence (DSSS)
2.4GHz
Spreads data packet over wide band,
effectively transmitting each bit on many
channels. Higher data rates (>1Mb/s), but
vulnerable to interference.
 100 to 500mW
 1-5 mile LOS (Line of Sight)

Frequency Hopping (FHSS)
900MHz
Change frequency after each data packet.
Slower data rates (115.2Kbd), but more
robust. Less vulnerable to interference.
 100mW to 1W

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20 mile LOS (Line of Sight)
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Power and Antenna’s

Under FCC regulations, the Effective Isotropic Radiated Power
(EIRP) must be less than 4W.

Radio power level of 1Watt, 100mW or 300mW allows the use of
gained antennas, which results in greater distances.

The drawback of using higher gain antennas is that a radio will pick
up more background interference, and is only recommended in
interference free areas.
900Mhz, (1W) + 6dB gain antenna = 4W EIRP
900Mhz, (250mW) + 12dB gain antenna = 4W EIRP
2.4 GHz, (100mW) + 16dB gain antenna = 4W EIRP
2.4GHz, (300mW) + 11dB gain antenna = 4W EIRP
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Main Groups for Wireless Ethernet
• 5.8Ghz 802.11a WiFi, Higher performan
with more bandwidth, less interference,
distance is shorter than 802.11b or g
• 2.4GHz WiFi (also known as “802.11b or g”)
very high data rates but very short distance
• 2.4GHz frequency hopping spread spectrum
high data rates but short distance
• 900MHz frequency hopping spread spectrum
lower data rates but longer distance
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The Common Security Concerns

Hacking
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Industrial Espionage
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Most common occurrence is when an intruder uses the same
modulation or spread spectrum as the target system
For protection utilize an AES system with WEP, WPA or WPA2
Make sure products include an embedded or physical firewall
Systems should have a data format that has a unique structure with
added security features, including network and address validation
Data can be encrypted using a high-security encryption algorithm
Send messages on an Exception Reporting protocol instead of
continuous transmission
Jamming

With enough resources any wireless system can be jammed. To
decrease this be sure the system utilizes wider channels, exception
reporting, Frequency Hopping techniques, or with Direct Sequence
proper encryption and powerful radios
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Security
• Wired Equivalent Privacy (WEP) – Lowest level of
encrypting data wirelessly with a 64 or 128 bit encryption
key.
• WiFi Protected Access (WPA) - uses a series of
mathematical algorithms to authenticate users. If a user
sends unauthorized data in short bursts the system
shuts down.
• WiFi Protected Access(WPA2) - provides government
grade security by implementing the National Institute of
Standards and Technology (NIST) FIPS 140-2 compliant
Advanced Encryption Standard (AES) encryption
algorithm and 802.1x-based authentication.
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MAC Address Filtering

A MAC (Media Access Control) address is a
unique identifiers for all Ethernet hardware
devices

Mac addresses are factory set and are expressed
as a 6 bytes string eg. xx:xx:xx:xx:xx:xx

Blacklist is a list of nominated MAC addresses
you don’t want to have access to your network

Whitelist is a list of nominated MAC addresses
that you want to allow access to your network

Cannot have both Blacklist and Whitelist
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Wireless
Ethernet
Terms
• Access Point
• This is the “Master”
ACCESS
POINT
unit. All Ethernet
messages are directed by
an Access Point Can be
Point to Point and/or Point
to Multipoint systems.
BRIDGE
• Client
• Are the “Slaves.” There
can be up to 255 Clients
connected to an Access
Point.
CLIENT
• Bridge
• A “Bridge” extends a
LAN – or connects
Ethernet devices to a LAN.
• For example, connecting a
PLC on a remote machine
to an existing wired LAN.
• Router
• A “Router” connects separate
LAN’s.
• For example, connecting two
separate LAN’s in two
separate buildings.
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CLIENT
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ROUTER
How Is A Connection Established?

Access Point
- On start-up begins
sending “Beacons” (Link messages)

Client

Scans for messages from AP and
attempts to establish a link with
the strongest radio signal
Access Point
PC
Client 1
Client 2
PC
Client 3
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Client Link Establishment
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Checks Authentication (System
address and Encryption)
Request a link (Association), Link
LED
AP

Link LED, Acts as a Master and
controls flow of messages
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…
Client N
Why Wireless Ethernet?
• Massive growth of Wired Ethernet in the
last 5 years
• Wireless Ethernet is an extension of
this growth
• Ethernet is well-known, carries multiple
applications
• Simple IP programming compared I/O
Telemetry programming and mapping
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Uses for Wireless Ethernet
• Developed for industrial customers &
Factory Automation
• Process control and automation
applications
- PLCs, DCS, SCADA, data acquisition,
wireless video
• Can handle multiple applications
simultaneously
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Typical Applications
Connecting a PLC to an existing wired LAN
Access Point
Connecting several PLC’s to an existing wired LAN
Client
Client
Access Point
Client
Client
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Applications

Most are PLC connections PLC to PLC or PLC to computer

Automation industries Pharmaceutical, Manufacturing, Ethernet
Enabled Transmitters, Video Security
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Process Control –
Data Loggers, RTU’s, Digital Recorders,
Video Security

SCADA market Oil & Gas, Water/Waste Water, Irrigation
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Multi-Tier, Multi-Drop SCADA Installation
SYSTEM A
Access Point 1
Client
Device Server
Client
PLC
ETHERNET LAN B
ETHERNET LAN A
SYSTEM B
Access Point 2
Client A
PLC
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Client B
PLC
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Client C
PLC
Wireless Ethernet Spanning Tree
•
•
The “Spanning Tree
Algorithm” function is
able to handle network
loops and provide
redundant paths in
networks.
Blocks redundant paths
until needed.
• Each Wireless Bridge OR WIRED ETHERNET has a priority which
determines where the node sits in the tree.
• When the highest connection point (255) fails the lowest connection
point (0) instantly activates to become the main node connection on
the network.
• There is some overhead in maintaining a network utilizing the
Spanning Tree Algorithm.
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Configuration and Diagnostics

Configuration and diagnostics via Web browser
(Internet Explorer)
– Typically there is an Easy Quick Start Configuration

Password protected

Configuration and diagnostics accessed remotely
via radio link

Radio signal, Background noise, and connection
diagnostics

Most have default configuration by DIP switch

Firmware easily upgraded
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Sample Quick Start Page
Quick Start
Configuration
Menu Item
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Ethernet Modems in the Real World
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Can I browse the internet?
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900Mhz, Yes, but expect to get web browsing
speeds slightly faster than a 56k dial up modem.
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2.4Ghz Yes, used in many commercial
applications, Hotels, Airports, etc.
Can it do video?

900Mhz - is not designed for that purpose unless
utilizing very high compression MPEG 3 or 4.

2.4Ghz – Can display realtime live video, more
reliable at 802.11b
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Key To Wireless Ethernet
1.
Long Range
900Mhz - Provides much greater distances (up to 60 miles)
2.4Ghz - High power WiFi 802.11 and FHSS.
2.
Security
900Mhz - 128 bit AES or 64 bit proprietary encryption
2.4Ghz - 40 or 104 bit WEP, WPA1 or WPA2 (128 bit AES)
3.
Reliability
900Mhz - less prone to interference provides better
penetration of signal and reflection off of surfaces.
2.4Ghz – Standard 802.11b WiFi, Proven Technology
4.
Repeater
900Mhz & 2.4Ghz – Most can double as a Repeater
5.
Configuration
900Mhz & 2.4Ghz – Configuration done via embedded web
pages that can be accessed remotely.
Installation
Installation is simple.
AP automatically sends out a beacon to detect available
clients and establish the link.
6.
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THANK YOU
Wireless Ethernet
The New Era of Data Transmission
Tim Gross
ELPRO Technologies
[email protected]
858-822-8818
© ELPRO Technologies
Think Wireless…Think ELRPO
NORCAL ISA