Since UDP is used to send location data to the server very efficiently, LAISYC 2-layer protocol by itself does not confirm that every location data fix successfully arrives at the server. In real-time tracking, the loss of occasional location fixes is acceptable since another location update will soon follow. However, since location data is often referenced after-the-fact to provide metrics (e.g. distance-traveled) and reconstruct users’ paths, the loss of large numbers of contiguous fixes can cause significant problems for applications. Extended gaps can result from lack of support for simultaneous voice and data services on mobile phones or “dead zones” with no cellular signal.
Adaptive Location Data Buffering increases the probability that most location data points will arrive at the server by performing occasional reliability checks. Before each location data UDP transmission, device-side APIs are checked to assess the current level of cellular signal and determine if a successful UDP transmission is probable. If not, the location data is buffered to either main memory or persistent storage on the mobile device. Once it is detected that UDP transmissions are likely to succeed, the buffered data is then sent via UDP and deleted on the device. Similarly, the device also occasionally checks with the server via the TCP protocol to ensure that it still has an open line of successful communication. If TCP fails, location data is buffered on the device until another future TCP check succeeds.
Adaptive Location Data Buffering therefore increases the chance that most location data will successfully arrive at the server, while preserving the efficiency of using UDP to send most location data.