
1.3 Design Goals 21
Because the zebras move over a wide area, not all of them are within range
of the base station, and it is impossible to predict which (if any) of the zebras
will be. As a result, the ZebraNet nodes must replicate data across the network.
The nodes transmit copies of their position data to each other as zebras come
within range of each other. When a zebra comes within range of a base station,
the base station reads all of that zebra’s data, including data it has gathered from
other zebras.
The ZebraNet group experimented with two data-transfer protocols. One
protocol—flooding—sent all data to every other available node. The other