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1/27Wireless LAN
Network Topologies
Geert BrackeAcc. Manager BeLux
2/27
Markets
Automation – Production, Service
Energy – Data Transfer, Management
Transportation – Data Transfer, Traffic Monitoring
Industrial Wireless LAN
3/27
Applications
Interconnection to Mobile Devices
Enlighting of Halls and Production Environments
Adding WLAN as Redundant Connection to Cable Installations
Replacement of Cabling
BAT54-Rail - Industrial Wireless LAN
4/27
Focussed on Security
There are three Types of Security :
> Safety of Operation using Redundancy
> Transmission Stability by optimzed WLAN Quality
> Network Security by Authentication, Encryption and Firewall
Industrial Wireless LAN
5/27
Possible topologies of networks
Advantages of the available possibilities
Disadvantages
Goals for improvement of WLAN availability
Threats to solve
possible solutions
Today’s possibilities with WLAN in industrial environments
6/27
Extension of existing LAN
Clients can be: Notebooks, PCs or BAT54-Rail in Client Mode
Frequency ranges: 5GHz or 2,4 GHz
Clients move in between Access-Points
Local Area Network
WLAN Infrastructures
Client
Access-Point
7/27
BAT54-Rail at Client or „Client Bridge“ Mode
LAN-LAN coupling via WLAN
LAN 1LAN 2
SNR signalization by LED for Clients and Point-to-Point-Connections
8/27
Enhanced Stability for WLAN
Two Radio Interfaces in access point and client
Redundant connection using Rapid Spanning Tree
Transparent to Industrial Ethernet Protocols (Layer 4)
Two Frequency Ranges simultaneously
Network
2,4GHz
Redundant Wireless LAN
5GHz
9/27
5 GHz Backbone
2,4 GHzwith Client
interconnection
WLAN Distribution
10/27
Relay functionality to interconnect
between radio cells
Illumination of areas (campus, hot spots)
Wireless Distribution
11/27Possible WLAN Topologies
LAN connectionMax. 6x P2P/Interface
AP1
AP 1
Local NetworkPoint-to-Point-Connection
AP 2 AP 3 AP 4
AC1/AP2 AC2/AP3AP n
12/27Map of customer site
Laboratory
Hall 9
Hall 6
13/27WLAN Topology at Customer
Laboratory Hall 9
Hall 6
Hall 9-1
Hall 6-1Hall 9-3
Hall 9-4
Hall 9-5
Lab 1 Hall 9-2
Local NetworkPoint-to-Point-Connection
4th floor
2nd floor
Ground
floor
14/27Threats for industrial WLAN networks
There are still some threats for WLAN in industrial environment:
- the connections are not stable enough
- rough environmental conditions
- Industrial Ethernet Protocols are very sensitive to packet latency and interruptions (Profinet, Ethernet/IP)
- Safety applications need very high availability (failover < 99,999%)
- Usability should be as easy as plugging cables
15/27
Field level
Control level
TRANSMITTER
PLC
VALVESENSOR
HMI / IPC
TRANSMITTER PENDENTBUTTONS
DRIVES &MOTORS
Enterprise Resource Planning
WLAN
Bluetooth/Zigbee/Wise/UWB/Varan etc.
Industrial network layer
16/27Utilizing Rapid Spanning tree for fixed network redundancy
17/27Utilizing Rapid Spanning tree for fixed network redundancy
Advantages:- Available today- standardized protocol (802.1w)- also used for ethernet networks
Missing:- No automatic configuration of the topology- fixed installation needed- still high handover times
18/27Goals for improvement of industrial WLAN networks
Goals:- rise the availability
- no more single points of failure
- easy-to-setup and to use
- reduce packet latency and handover times
Achieve by:- create redundancy (which is basically controversial to 802.11 MAC functionality)
using other topology: meshed networks
19/27Meshed network topology
History:
- Mid 1990ies created by DARPA for military applications on battlefields- Improved by R&D companies like SRT International- Wikipedia offers today more than 50 possible routing protocols for meshing
Features:
- Better scalability: network power increases by each hop added to it- Automatic configuration and scalability- very fast or even no handover times- increase of availability of WLAN network- quick and easy setup - reduction of cables needed
20/27
Gateway to Sensor networks
search for the best itinerary self healing network no cabling
WAN/LAN-Gateway
Meshed networks
21/27
fast handover allways more than one connection avilable Increase of availability
WAN/LAN-Gateway
Meshed networks
22/27
search for the best itinerary Addition of bandwidth Increase of availability
WAN/LAN-Gateway
Meshed networks
23/27
Gateway to Sensor networks
more CPU power needed routing capabilities are not part of basic access points at least two WLAN interfaces needed
WAN/LAN-Gateway
Meshed networksAccess Points need to
-Route-Negotiate-encrypt
24/27
The way to keep the overview - Management System
A meshed network is basically self-configuring
How to keep the overview?
Over the current topology
Over possible vulnerabilities
Over possible attacs
Management Systems today base on SNMP protocol (polling)
Mesh APs need to declare themselves LLDP
Meshed networks have higher demands to management than current WLAN!
Wireless management
25/27
Network Security is still a must!
A meshed network is very flexible
Authentication mechanisms are very static today
802.1x needs external servers
How to know which device may connect?
How about Rogue APs?
802.1x can be part of the AP already (BAT54-Rail Version 7.10)
Meshed networks have higher demands to security functionality WLAN!
Wireless security
26/27
Hirschmann BAT54-Rail
The operating system offers many capabilities today
IP routing is already implemented
802.1x internal server and supplicant is available
Equipped with two WLAN interfaces
Equipped with powerful Intel CPU and sufficient memory
It’s more than just a basic access point
Meshing will be available by software update. No new hardware needed.
Roadmap:
Find out which protocol is best (IEEE 802.11s is in discussion but maybe not suitable for industrial applications): Q1/2008
Implement and test: Q3/2008
The roadmap to Meshing
27/27
Thank you for your attention!