MIL-STD-187-721 Interoperability And Performance Standard For Advanced Adaptive Hf RadioThe purpose of this document is to describe the technical parameters for adaptive high frequency HF radio that are more advanced than those described in MIL-STD-188-141. The advanced technology contained in this standard will guide the planning of military adaptive HF radio network technology into the 21st century. To fully understand and utilize this document, it is necessary to refer to portions of MIL-STD-188-141.

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MIL-STD-187-721D

5.6.6.1 Adjust slot width.

When sent as part of a transmission that requires slotted responses, this CMD requires that all slots be lengthened by the time offset in the CMD. TB7 shall be set to 0 to limit the slot adjustment to a maximum of 32 seconds. When sent in a transmission that does not require slotted responses, this CMD shall be ignored.

5.6.6.2 Station busy.

This CMD may be sent in response to a call when the called station is currently unable to accept the call. The calling ALE controller may elect to call again after time "T" (the current time plus the time offset in the CMD).

5.6.6.3 Channel busy.

This CMD directs an ALE controller not to use a channel until after time "T". By default, the channel carrying the CMD is not to be used until after time "T"; however, a different channel may be designated as busy by placing a channel designator (see 5.3) in ALE word bits W4-10 of a DATA word that immediately follows the channel busy CMD. This channel designator shall be interpreted as an absolute channel number (not as an offset from the channel carrying the CMD).

5.6.6.4 Set dwell time.

When received following a channel busy CMD, the set dwell time CMD shall cause the receiving ALE controller to increase its scanning dwell time on the designated channel only to the value indicated in the Time Offset field of the set dwell time CMD. TB7 and TB6 shall both be set to 0 to limit the dwell time on a channel to no more than 4 seconds.

5.6.6.5 Halt and wait.

An ALE controller receiving this CMD shall stop scan (without tuning or responding) and wait until time "T" for further transmissions. If none are detected, it shall resume scanning. TB7 shall be set to 0 on transmission, and ignored on reception to limit the waiting period to 32 seconds.

5.6.6.6 Contact later.

A station receiving this CMD is requested to call the station sending CMD at the designated time "T" if the time offset field is not all 1's, otherwise at the date and time in the DATA word that immediately follows the CMD. The call should be placed on the channel carrying the CMD, unless another channel is specified in a DATA word (formatted as in 5.6.6.3). If a date and time DATA word and a channel designating DATA word are both sent following the CMD, the date and time word shall be sent first.

5.6.6.7 Meet me.

a. A station receiving this CMD is requested to call the station sending the CMD at the designated time "T" if the time offset field is not all 1's, otherwise at the date and time in the DATA word that immediately follows the CMD. The call should be placed on the channel carrying the CMD, unless another frequency is specified in a DATA word (formatted as