NAS surveillance data latency requirements: History and rationale

This paper has summarized the various NAS latency requirements within the NAS-RD and their allocation to phases of surveillance data latency as shown in Figure 6. The NAS-RD sets the maximum end-to-end latency for surveillance data display in terminal and en route operations is set at 2.2 and 3.0 seconds, respectively. Existing and planned NAS subsystems affecting or affected by this latency were identified and described. Where existing systems depart from the standards we have highlighted those deviations and explained the circumstances causing them.