AVR2070
3
8240B-AVR-06/09
2.1 Overview of RUM A RUM network is constructed around a coordinator. The coordinator is the only node
that keeps any state information about the network, so that the other nodes do not
have to store any network information. This allows for low cost hardware for both
routers and end-nodes which comprise the bulk of the network. A router can act as a
multi-hop intermediary for other nodes, while an end node can attach to a network,
but cannot associate child nodes. Any node is usable as a data node or actuator.
The network is organized as a tree, with the coordinator having a number of
associated nodes as children, and router nodes having their own associated children
as well. Each node has exactly one parent, which is also the node's link to every
other part of the network.
Figure 2-2 RUM Tree Topology Example
Appendix A contains a detailed description of the RUM protocol.
2.2 Overview of IPv6 and 6LoWPAN The features of IPv6 and 6LoWPAN allow the RUM coordinator to act as an edge
router in the worldwide network. The full functionality of these features are best
utilized on the AT91SAM7X-EK development kit which provides an Ethernet
connection. This application setup is described in section 4.
Any wireless node connected to the coordinator/edge router will obtain a unique IPv6
address based on its RUM short address. Depending on the application, the wireless
node can then report sensor data directly to the coordinator/edge router, some other
server or IPv6 addressable device via the IPv6 internet connection. This node can
also receive commands when necessary based on application software.
More details about the interaction between RUM/6LoWPAN can be found in Appendix
C.