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

g.  In mode 01 or mode 10, the Control field is set to 1000000 when the channel or frequency designators (respectively) are positive offsets relative to the initial channel, or to 1100000 for negative offsets.  In all other cases, the Control field is set to 0000000.

h.  When the set of channels to be evaluated must be negotiated before the channel scan, channel designators are sent following the Channel Scan Request CMD word in DATA words.  Up to three channel designators are sent in each DATA word.  The order of channels scanned is determined by the order the channels are listed.

(1)  The first channel scanned after the initial channel is designated in the most significant character position of the first DATA word.

(2)  The scan proceeds in order through the remaining channels designated in the first

DATA word followed by channels designated in subsequent DATA words.

(3)  Unused character positions in the final DATA word shall be filled with 0's.

i.  When the caller provides an explicit list of channels following its channel scan request, the responder may either accept this list without modifications by returning a channel scan request with a mode of 11, or it may add channels to the list by returning a channel scan request with a mode of 01 followed by the list of channels to be added.

J.  When the correspondence of channel numbers to frequencies is different for the stations wishing to poll before linking, the set of frequencies to be evaluated shall be negotiated before the channel scan.  In this case, frequency designators are sent following the channel scan request CMD word in DATA words.  One frequency designator is sent in each DATA word

in positions W5  through W24.  W4  is set to 0.  The order of frequencies scanned is determined by the order the frequencies are listed.

(1)  The first frequency scanned after the initial channel is designated in the first DATA

word.

(2)  The scan proceeds in order through the frequencies designated in subsequent DATA

words.

k.  When the caller provides an explicit list of frequencies following its channel scan request, the responder may either accept this list without modifications by returning a channel scan request with a mode of 11, or it may add frequencies to the list by returning a channel scan request with a Mode 10 followed by the list of frequencies to be added.

5.4.4  LQA report protocol.

a.  The unilateral LQA data derived from measurements on traffic and sounds received on several channels can be exchanged among the stations sending and measuring those transmissions to provide each with bilateral LQA data for those channels.  Thus, the LQA

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