Issue link: https://resources.mouser.com/i/1520712
16 Next-Gen Connectivity for Smart Living Time Difference of Arrival The TDoA method is a highly scalable process for determining the location of tags within a venue. Because tags only need to transmit once during the process, they use very little power and, therefore, have a very long battery life. Multiple anchors are deployed in fixed and known locations and are tightly time-synchronized. When a mobile device sends a "beacon" or "blink" signal, each anchor that receives the signal timestamps its arrival based on the common synchronized time-base. The timestamps from multiple anchors are then forwarded to a central location engine, Figure 5: Two-way ranging with 2D/3D assets and data tag backhaul. (Source: Qorvo) Figure 6: Determining location with multiple anchors using time TDoA. (Source: Qorvo) which runs multilateration algorithms to determine the device's location based on the differences in the time that the signal arrived at each anchor. The result is a 2D or 3D position for the mobile device (Figure 6). Reverse Time Difference of Arrival It is also possible to implement a reverse TDoA system, which works a bit like GPS. Here, the anchors transmit synchronized blinks (with fixed/known offsets to avoid collisions), and the mobile devices use TDoA and multilateration algorithms to compute their location (Figure 7).