system. Areas that have been improved under the
Link-16 system include the following:
Number of Participants
Track Numbers
Track Quality
Track Identification
Friendly Status
Granularity of Measurement
Relative Navigation
Electronic Warfare
Land Points and Tracks
NUMBER OF PARTICIPANTS. —The number
of units that can participate in a Link-16 net has been
increased dramatically over that of Link-11. The
JTIDS Unit number, or JU, is a five-digit octal
number from 00001 to 77777. This allows for a
maximum of 32,766 possible JUs. Addresses 00001
to 00177 are normally assigned to units that have the
need and capability to participate in both Link-16 and
Link-11. When a unit participates in both Link-11
and Link-16, it must use the same address on both
links. For example, Link-16 JU 00043 is the same as
Link-11 PU 043.
TRACK NUMBERS. —Link-l6 replaces the old
four-digit (octal) Link-11 track numbers with a five-
character alphanumeric track number. The track
number can be within the range 00001 to 77777
(octal) or 0A000 through ZZ777. This allows for a
maximum of 524,284 track numbers, compared with
the 4,092 available with Link-11. One reason for the
need for the additional track number is that Link-16
cannot operate in the track number pool mode, in
which a common pool of track numbers is shared by
several PUs. Every JU must be assigned a unique
block of track numbers.
To maintain interoperability with Link-11,
Link-16 track numbers 00200 through 07777
designate the same track as Link-11 track numbers
0200 through 7777.
TRACK QUALITY. —The Track Quality (TQ)
value used by Link-16 relates to the accuracy of the
reported position of the track. The TQ has a range of
0 to 15. To achieve the highest track quality, the track
must be within 50 feet of the reported position.
Link-11 uses the update rate to determine track
quality. Using Link-11, a track that is reported by a
PU at every interrogation is usually assigned a TQ of
7. Therefore, a Link-11 air track with a TQ of 7 can
be more than 3 nautical miles from its reported
position.
TRACK IDENTIFICATION. —The Link-16
system greatly expands the information that is
reported with Track Identification (ID). The new ID
reports include fields for platform, activity, specific
type, and nationality of the track. Additional
provisions have also been added to identify a track as
“Neutral,” and the Unknown Assumed Enemy ID is
changed to “Suspect.”
FRIENDLY STATUS. —The Link-16 system
also provides for more detailed status reports from
friendly aircraft. The following fields are added to
Link-16 friendly status reports: equipment status,
ordnance inventory, radar and missile channels, fuel
available for transfer, gun capability, and station ETA
and ETD.
INCREASED GRANULARITY. —Granularity
refers to how precisely an item is reported in the link
message. Link-16 has made major improvements in
the granularity of reports concerning track position,
air track speed, altitude, and lines of bearing.
LINES AND AREAS. —The Link-16 system
allows the reporting of multi-segment lines and areas
of all sizes and descriptions. Link-11, for comparison,
only allows reports of areas that are limited in size
and are circles, ellipses, squares, or rectangles.
Link-11 does not have the capability to report lines.
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