its settings.
AirFinder Gateways aggregate and transmit AF3 asset tracking tag up-link messages, as well as any other
traffic from Location Beacons, and Access Points to the AirFinder Precise Location Service cloud platform.
Gateways are connected to the Internet via an IoT (LTE) network connection. In some rare cases, the
Gateway may have an Internet connection via a LAN or other backhaul method.
Any messages to AF3 Asset tracking tags or other infrastructure coming from the AirFinder Platform are
transmitted via that cloud to the on-site Gateways. Gateways then pass on the messages, as required by
each message type, to individual hardware or categories of hardware.
AF3 Tag location update event:
The AF3 location update process is outlined below:
1.
Tag scans for all available LBs
2.
Tag generates 'target' LB list, then resumes scanning
3.
When the Tag detects a beacon message from one of the targeted LBs, it replies to request a
ranging sequence. The reply occurs on a random channel chosen by the LB and indicated in the
beacon message.
4.
After receiving the Tag's range request message, the LB responds with an acknowledgement on a
different channel, chosen by the Tag.
5.
In response, the Tag transmits a ranging start message to the LB. Both Tag and LB then hop to the
first channel in the agreed-upon, randomized hop map.
6.
The Tag transmits a ~40us long CW tone. Precisely 80us later, the LB replies with a ~40us CW
tone at the same frequency.
7.
The Tag and LB hop to the next frequency in the map and repeat the prior step.
8.
When all hops are complete, the Tag and LB proceed to the randomly selected data transfer
channel.
9.
The LB transmits IQ samples collected during the Tag's transmission in a 2Mbps burst up to 1ms
in length.
10.
The Tag acknowledges the IQ samples, and the over-the-air portion of the location update is
complete.
After the Tag has acquired the LBs IQ samples, it performs a sequence of calculations to estimate the
range to the LB. This entire ranging process lasts 13 -- 40ms, depending on the number of hops in the
selected hop map. After acquiring a sufficient number of ranges (generally 4-6), the tag performs a
trilateration based on the known beacon locations (xyz coordinates advertised by the location beacon) to
estimate its own position.
2.
AirFinder Power Cradle DC Power (WF-402D)
a.
Hardware Verification
o
Remove AirFinder Power Cradle DC Power (WF-402B) from packaging.
o
Visibly inspect front and back of unit (see Images 23 and 24 below)
▪
If not damaged, proceed to the next step.
