Operation
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Figure 8.10
Eliminating a bottleneck
1. Bottleneck
2. WirelessHART gateway
3. Possible position of an additional WirelessHART device eliminating the bottleneck
Expand the Network
In an industrial environment, there are several potential obstacles for radio waves, for example
buildings, walls, pipes, or even moving obstacles like trucks. Those obstacles can reflect, bend,
diffuse or block radio waves. The effects of reflection, bending and diffusion create new waves
which interact with the original ones and with each other. They can amplify or nullify each other.
Due to the interference of reflections, moving the antenna a few centimeters can help. If there
are obstacles blocking data transfers between wireless devices, add additional devices to
provide alternative communication paths. The more devices exist in a WirelessHART network,
the more reliable it gets.
Optimize Coexistence with other Wireless Networks
WirelessHART networks use the frequency spectrum between 2400 ... 2483.5 MHz according
to IEEE 802.15.4. Various other wireless technologies also use this frequency spectrum, for
example WLAN (IEEE 802.11) and Bluetooth (IEEE 802.15.1). Measures must be taken to
ensure that the various wireless technologies do not affect each other.
If there are problems with other wireless technologies disrupting the WirelessHART network,
create a channel blacklist that makes the WirelessHART gateway skip certain channels known
to provide persistent interference. See chapter 5.2.1
If possible, you can also manage the frequencies used by other networks and block the usage
of channels already used by the WirelessHART network (frequency management).