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DNT24 Integration Guide - 10/19/11
2.2 Point-to-Multipoint Systems
Figure 2.2.1 shows the topology of a point-to-multipoint (star) system, which consists of a base and more
than one remote in a single network. Point-to-multipoint systems are typically used for data, sensor and
alarm systems. While most traffic in a point-to-multipoint system is between the base and the remotes,
DNT24 technology also allows for
peer-to-peer
communication from one remote to another.
Figure 2.2.1
2.3 Store-and-Forward Systems
Figure 2.3.1 shows the topology of a
store-and-forward
system, which consists of a base, one or more
routers, one or more remotes, and
two or more
networks. Networks in a store-and-forward system form
around the base and each router. The base and the routers are referred to as the
parents
of the networks
they form. The rest of the radios in each network are referred to as
child
radios. Note that a router is a
child of the base or another router while being the parent of its own network. Each network parent trans-
mits beacons to allow child radios to synchronize with its hopping pattern and join its network. Different
frequency hopping patterns are used by the parent radios in a system, minimizing interference between
networks.
Store-and-forward systems are used to cover larger areas than is possible with point-to-point or point-to-
multipoint systems. The trade-off in store-and-forward systems is longer delivery times due to receiving
and retransmitting a message several times. Store-and-forward systems are especially useful in applica-
tions such as agriculture where data is only collected periodically.
