XB24-BPDK Digi International/Maxstream, XB24-BPDK Datasheet - Page 25

• Manufacturer Part Number: XB24-BPDK
• Description: KIT DEVELOPMENT XBEE SERIES 2
• Manufacturer: Digi International/Maxstream
• Series: XBee™r
• Type: 802.15.4/Zigbeer

Specifications of XB24-BPDK

• Frequency: 2.4GHz
• For Use With/related Products: XBee™ Series 2 Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

XBee ZNet 2.5/XBee‐PRO ZNet 2.5 ZigBee OEM RF Modules v1.x4x
R1
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.
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.
Figure 3‐08. Sample Route Request (Broadcast) Transmission Where R3 is Trying to Discover a Route to R6t
When the destination node receives a route request, it compares the ‘path cost’ field against
previously received route request commands. If the path cost stored in the route request is better
than any previously received, the destination node will transmit a route reply packet to the node
that originated the route request. Intermediate nodes receive and forward the route reply packet
to the source node (the node that originated route request).
© 2008 Digi International, Inc.
Node
R3
R5
C
R3
R2
Destination Address
Router 6
Router 6
Router 6
C
Next Hop Address
Coordinator
R4
R5
Router 5
Router 6
R6
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