The AiRISTA Flow RTLS tags communicate for several purposes. First, they communicate to report their location or other event-based information, such as during a button press or security-switch pull. Second, they communicate to perform maintenance operations which allow messages to be received, and programming changes and firmware updates to happen over the wireless network. To report location, tags can operate in two modes: Associated Mode and Blink Mode. The location update mode is programmed independently of the Maintenance Mode. Tags must always use Associated Mode to do a maintenance session.
Each method has advantages and disadvantages and is more suited for specific use cases.
Tag Associated Mode
In “associated mode” tags are configured to associate and authenticate to the WLAN for each location and maintenance update. In this mode, tags send probe requests to APs on their SSID and measure AP responses to obtain RSSI. Tags then associate/authenticate to the network to send this data to the server. In this mode, tags are capable of two-way communication and require an IP address for communication. Typically tags are programmed for associated mode location updates when utilizing messaging or alerting, as in the case of tracking employees, personnel, or patients. Associated mode is also used for “maintenance” operations and to change tag configuration or update FW over the WLAN. To facilitate proper communication between AiRISTA Flow tags and the ARC server for associated mode operations a minimum of -65 dBm coverage.
Tag Blink Mode
In “blink mode” tags transmit one-way (layer 2) frames to the wireless network for tracking purposes and do not associate/authenticate to the network. Instead Access Points “hear” the transmissions and record the RSSI (from the tag) and send that information on to the AiRISTA Flow RTLS Controller. This connectionless approach means that tags do not require an IP address to transmit their payload. Various layer 2 protocols are used in configuration of the tag depending on the network in place.