Maximum distance and speed for communication in StarTrek franchise [duplicate]

Question

In the middle of TNG: "Transfigurations" an alien ship is detected on long-range sensors. Worf says, that it travels with Warp 9.72 on interception course and it will take 10.53 hours to meet it.

We don't know the exact relativistic speed equivalent of Warp 9.72, but we may assume, that it is more than Warp 9, i.e. more than 1516.381 c. This speed (according to the same source) allowed to travel 4.152 light years in 24 hours. (4.152 / 24) * 10.53 = 1.82169 light years of estimated distance between Enterprise and that alien ship. And yet, Worf was ordered to try to hail them.

Is it really possible (in StarTrek franchise) to estabilish audio communication and "talk" to a ship, that is nearly two light years ahead and travels more than 1500 times faster than light speed?

Answer 1

Weeellll... subspace communications... en.memory-alpha.org/wiki/Subspace_communication

Depending on the actual distance between a vessel and the nearest subspace relay beacon, real-time communication was possible. An example of this is when Starfleet Lieutenant Reginald Barclay contacted the USS Enterprise-E, which was seven light years away from his location on the Jupiter Station, and spoke real-time to the ship's Counselor, Commander Deanna Troi.

Some notes on the long range sensor en.memory-alpha.org/wiki/Long_range_sensor_scan

In 2267, the sensors of the USS Enterprise were able to scan out to one parsec (3.26 light years) and give a near instantaneous result. (TOS: "The Enterprise Incident")

In 2367. Lieutenant Commander Geordi La Forge stated that the long range sensors aboard the USS Enterprise-D were able to scan a radius of ten light years within a 24-hour period; effectively, one sector per day. (TNG: "The Wounded")