industrial wireless book special edition - Networking ...

industrial wireless
Industrial wireless mesh networks
can use IEEE802.11 standards
There are many types mesh network technology which, taken together, can bring wireless connectivity to
just about every conceivable industrial and process application. However, there is only one – IEEE802.11n –
which truly meets the throughput and reliability demands of industrial automation, plus compatibility with
enterprise IT standards says Advantech’s Alex Tsai and Kunhong Chen
can provide interactive Scada and telemetry in
places and over distances where it simply is
not possible to get a wire or a signal in any
other way. Likewise, WSN provides short range,
low data rate connectivity with a power budget
applicable to disposable batteries. However,
only IEEE802.11n technology presently offers
network-friendly IP routing and the sort of data
rate applicable to industrial automation applications
in a mesh topology format.
Routing technique largely determines the
characteristics of a mesh network. The routing
function propagates the message by hopping
the data from node to node along a path until
the destination is reached. To ensure the availability
of a path, a routing network must allow
for a continuous connection and reconfiguration
around broken or blocked paths through
the use of self-healing algorithms. Self-healing
capabilities enable routing based networks to
operate when one node breaks down or a
connection goes bad. As a result, the network
is considered to be very reliable since there is
often more than one path between a source
and a destination in the network.
ANY NETWORK which can function without preordered
infrastructure may be described as
having mesh topology. To meet this requirement,
each node must not only capture and
disseminate its own data, but also serve as a
relay for other nodes. In other words, it must
organise its own collaboration to propagate
data across the network.
The expression ‘mesh topology’ generally
suggests MANET – as in Mobile Ad hoc Network
– or WSN (as in Wireless Sensor Network), but
it may also be applied to freely associated
nodes operating with standards-based WLAN
technologies such as IEEE802.11n. Of course
networks constructed with GSM mobile or
wireless sensor comms technology have
incredibly useful properties. For instance GSM
ARTWORK: FRANK OGDEN
Mesh network parameters
The three types of mesh with different uses are
detailed here, all of which use the standardsbased
features available in IEEE802.11n
hardware. However, for the greatest flexibility
a hybrid configuration is probably the most
useful as will be shown.
Client. Using one type of radio device e.g., an
EKI-6340-3, as a client mesh provides peer-to-peer
networks among client devices and the client nodes
to perform routing and configuration functions.
4
Infrastructure
industrial ethernet book
Hybrid
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