AG Electronica XBee 2 Series Manual page 23

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XBee Series 2 OEM RF Modules ‐ ZigBee ‐ v1.x2x [2007.07.019]
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Figure 3‐05. Sample Transmission Through a Mesh Networkʺ
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AODV (Ad-hoc On-demand Distance Vector) Routing Algorithm
Routing under the AODV protocol is accomplished using tables in each node that store the next
hop (intermediary node between source and destination nodes) for a destination node. If a next
hop is not known, route discovery must take place in order to find a path. Since only a limited
number of routes can be stored on a Router, route discovery will take place more often on a large
network with communication between many different nodes.
Table 3‐01.
Node Destination Address
Router 6
R3
Router 6
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Router 6
R5
When a source node must discover a route to a destination node, it sends a broadcast route
request command. The route request command contains the source network address, the
destination network address and a path cost field (a metric for measuring route quality). As the
route request command is propagated through the network (refer to the Broadcast Transmission),
each node that re-broadcasts the message updates the path cost field and creates a temporary
entry in its route discovery table.
© 2007 Digi International, Inc.
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Next Hop Address
Coordinator
Router 5
Router 6
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Chapter 3 ‐ ZigBee Networks
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