BeaconRequest Command transmission duration

I would like to know the duration of the BeaconRequest command transmission. I have been reading the product manual, Product Manual v1.xEx - 802.15.4 Protocol, and I haven’t been able to find this information anywhere. I believe that closest I have come is on page 18, under step 2 of the End Device Start-up, “The Active Scan selects one channel and transmits a BeaconRequest command to the broadcast address (0xFFFF) and broadcast PAN ID (0xFFFF). It then listens on that channel for beacons from an Coordinator operating on that channel. The listen time on each channel is determined by the Scan Duration (SD) parameter.”
Any help would be greatly appreciated.

What you want to know is the duration of an active scan? Rather than a Beacon Request transmission duration? Well, the latter is easily calculated, as are any 802.15.4 frames. The IEEE standard defines it all. Transmission, say, in 2.4GHz is a fraction of a millisecond. But unicast frames can have a MAC ACK request enabled, meaning the transmission isn’t fully complete until ACKed or timed out.

Time to do an active scan depends on your choices of which/how many channels to scan (avoid needless channels by having a priori), dwell time on the channel (beacon request/response or waiting for 1 beacon interval depending on topology). Plus a bit for receiver settling time each channel change.