User Manual

1-4 Millennial Net
Introduction
System Modules
The modules of a wireless sensor network enable wireless connectivity within the network,
connecting an application platform at one end of the network with one or more sensor or
actuator devices at the other end. As shown in
Figure 1-2, the gateway and end node modules
create a transparent, wireless data path between the application platform and sensor.
Figure 1-2. Basic wireless sensor network components
Exchange of analog or digital information between an application platform and one or more
sensor nodes takes place in a wireless fashion. In this example, the data path between the
gateway and end node is referred to as a single-hop network link.
To extend the range of a network or circumvent an obstacle, a wireless mesh node module can
be added between a gateway and an end node as shown in
Figure 1-3.
Figure 1-3. Adding a mesh node module
This particular example represents a multi-hop data path, in which data packets are handed off
from one module to the next before reaching their destination (gateway-to-mesh node-to-end
node and vice versa).
More elaborate network layouts are discussed later in Network Topologies,” but for now, we’ll
take a closer look at each of the network components shown in
Figure 1-3.
Application Platform
This is the network device (Network Controller, PC, handheld, etc.) used to monitor and control
the actions of the various sensors and actuators that are connected to the wireless sensor
network. The application platform is capable of making decisions based on the information it
gathers from the network. Typically, the wireless sensor network will come with an API and/or a
GUI used to interface with the wireless modules.