+/* Difference between Unix seconds to GPS seconds
+ GPS epoch: 1980.1.6 00:00:00 (UTC); Unix time epoch: 1970:1.1 00:00:00 UTC
+ Value is calculated on Sep.6 2019. Need to be change if International
+ Earth Rotation and Reference Systems Service (IERS) adds more leap seconds
+ 1970:1.1 - 1980.1.6: 3657 days
+ 3657*24*3600=315 964 800 seconds (unix seconds value at 1980.1.6 00:00:00 (UTC))
+ There are 18 leap seconds inserted after 1980.1.6 00:00:00 (UTC), which means
+ GPS is 18 larger. 315 964 800 - 18 = 315 964 782
+*/
+#define UNIX_TO_GPS_SECONDS_OFFSET 315964782UL
+#define NUM_OF_FRAMES_PER_SFN_PERIOD 1024
+#define NUM_OF_FRAMES_PER_SECOND 100
+