industrial wireless book special edition - Networking ...

Extended WLAN is a single network
Administering remote installations centrally using thin access point
and wireless controller technologies provides added value for the
company and its service provider customers says Wolfgang Bölderl-Ermel
WITH WIRELESS networks becoming more
important, the need for integrated wireless
network management solutions linking office
and production areas is important.
However, wireless components such as
wireless access points (WAPs) and clients must
be both industry-proof and and usable in the
office. They should also be capable of being
jointly operated and managed in the same
wireless network.
Computer centre example
The Siemens Erlangen Frauenaurach computer
centre is one of two redundant computer centres
in a redundant dark fibre backbone that connects
several of the company’s sites. The centres in
this Metropolitan Area Network (MAN) provide
and coordinates all connected APs and manages
its clients such that the wireless LAN works as
an individual, centrally administered IP sub
network. This reduces on-site installation costs
and the need for distributed AP servicing, and
gives expanded central control functions.
This type of WLAN architecture simplifies
network topology bridging between offices and
the production environment. This is because it
allows a universal, integrated wireless network
to be used for all APs and clients across
company divisions, such as Internet, operating
data, automation equipment, VoIP and WLAN
capable telephone integration.
Comments Helmut Mack, project manager at
the Erlanger computer centre: ‘The thin access
points can be conveniently administered from
Industrial Wireless
The wireless controller implements a single network
technical departments with individual network
services. Intranet and Internet access services
use a standardised, transparent firewall, information
security and server operation processes all
in a single package.
Examples include APs and Clients for industrial
wireless LAN applications indoors, outdoors or
in Zone 2 hazardous areas. Included are up to
three wireless modules, internal or external
antennas and RJ45 and fibre optic cable
connections.
The ‘thin access point’ Scalance W786 2 HPW
operates with, or on, the company’s HiPath
Wireless Controller. Thin access point solutions
place very little 802.11 intelligence on the AP –
instead, they pass the 802.11 packets to a
centralised controller or switch. The wireless
controller acts as a dynamic router that combines
sponsored by Advantech
industrial ethernet book
a central point. After the initial installation,
nobody from our company has to be on site to
put extra or replacement equipment into
operation, to install software updates or to
make changes to the configuration.’
Users can connect the hardware without
recourse to trained personnel. The devices then
automatically and securely log onto an available
controller using a secure, encrypted tunnel
connection via a fibre optic backbone. The
device is configured and all tasks can be handled
controller based from the central office.
Up to 200 controller-capable APs for as many
as 4096 simultaneous users can be centrally
managed and coordinated. Using the HiPath
Wireless Manager, several controllers and
hundreds of access points are administratively
grouped together. This wireless manager
presents the WLAN as several subnetworks, but
it also manages connections such that participants
can move around within the network. It
also keeps an eye on security rules and the
defined quality for different devices.
In operation
One of the beneficiaries is Siemens Gerätewerk
Erlangen (GWE), which draws its IT services
from the computer centre at the same site. Take
the reliable picking in GWE’s picking warehouse.
Employees accept their orders as bar codes with
a scanner that wirelessly communicates with
higher level order management system.
The industrial wireless LAN is centrally
managed from the Erlangen and Karlsruhe
computer centres where redundant wireless
controllers are installed. The redundant MAN,
which uses Coarse Wavelength Division Multiplex
(CWDM) laser technology for the large sites, and
which allows eight simultaneous Gigabit connections,
connects the Nuremberg, Regensburg,
Amberg and Chemnitz sites via the ‘dark fibre’
fibre optic ring. On site technical divisions
centrally draw upon tailored network services
and don’t need their own special expertise or
hardware.
The services are based on standardised, cost
effective and proven processes and protocols.
Currently, around 360 HiPath AP3610 and
AP3620 series APs are operating in the MAN,
together with over 80 hardened Scalance W
thin access points.
Wolfgang Bölderl-Ermel works for Siemens Industrial
Communications
First published in the industrial ethernet book November
2010
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