how network coordinator,cluster head and bottom node are different?

[immadi.jagadish]

In any wire less sensor network we have three nodes
1.network coordinator
2.cluster head
3.bottom node
are they different in their hardware or same?
if same,then how they are differnt in their functionality?

 

[gartner]

1. Its ambiguous from the picture, but the network coordinators are presumably talking to a router over ethernet and to cluster heads over Zigbee. The network coordinators would a Zigbee network based node.
2. The cluster heads must be router nodes. These nodes are capable of forwarding Zigbee packets to increase the effective range. From a Zigbee perspective there is no difference
3. The bottom nodes are not responsible for routing, so the may be end nodes or router nodes.

All three types of Zigbee nodes may be run on identical hardware.
The application software may also be different, but this does not effect the hardware unless there are memory limitations.