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UK Tactical Data Systems
Reference Guide
Tactical Data Links
Link
1
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Designed in the late 1950s, Link 1 has low capacity and is
usually insecure. It is used between ground-based Air Surveillance and
Control system (ASACS) units, but it may also be used by ground-based mobile
units to connect into a static C2 system. Link 1 units are allocated areas
of responsibility, termed Track Production Areas (TPA), whose boundaries are
overlapped by Track Continuity Areas (TCA). Tracks within the TCAs are
exchanged automatically between the adjacent units, but wider area data
exchange may also be carried out within operator-defined Area of Operational
Interest (AOI)s.
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Purpose
Exchange air tracks and EW strobes in near real-time.
Attributes
Simplex or duplex, Point to point
Not normally encrypted.
Data rate 600 or 1200 bps (but may be operated at any
multiple of 600 bps if agreed to by the participants).
Format
‘S’ series messages
128 bits (30 bits overhead, 2 x 49 bit paired data
messages).
Track
No
15 bit NATO Track Numbers (NTN) (2-letter alpha bi-graph,
3 digit octal number. The bi-graph indicates the originating unit and not the
current tracking unit).
Medium
Landline (cable, microwave, SATCOM) or multi-channel
radio. Synchronous Differential Frequency Shift Keying (DFSK) waveform.
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Strengths
Widely used throughout Europe.
ECM-resistant, as is inherent in a buried cable or
microwave link.
Limitations
No free text capability.
Track management is basic (e.g. change Identification (ID)).
No C2 capability (but target engagement and fighter
allocation status can be handled).
Slow - track telling is prioritised by category and tracks
with low priority (typically friendlies) can be minutes out of date.
Standards
STANAG 5501
STANAG 5601
SOPs
ADatP-31
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Link 14
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Link 14 is a nonreal-time radio teletype link that allows TDS equipped units to provide a broadcast to other units without TDSs. The HCI is either a
simple list on a teleprinter or a pictorial presentation on an Autoplot Visual
Display Unit (VDU). Link 14 was designed to pass track data, but the link is
very slow and so it is now used primarily to provide a (High Interest Track
Broadcast (HITB) to supplement real-time data links and voice reports.
Although it was discontinued as a NATO TDL from 2000, it is still likely to
remain in service for several years. Some UK platforms (E3D and T42/CVS) remain fitted but it does not form part of the current UK TDL operational TDL capability
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Purpose
Exchange of EW data, air, surface and subsurface tracks,
and points and free text.
Attributes
Broadcast.
Encrypted (BID 850).
Data Rate 75 bps.
Format
Man-readable character strings.
Track No
12 bit Data Link Reference Number (DLRN) (4 digit octal
number).
Medium
HF, UHF or SHF satellite Radio Teletype (RATT).
Uses Frequency Shift Keying (FSK) with a 2-tone Keyer.
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Strengths
The design of the Teletype transmission allows reception
over very long-ranges.
It is more resistant to jamming on HF than is Link 11.
Limitations
Although there is a standard NATO format for Link 14,
almost nobody uses it and numerous national formats have been developed, not
all of which are interoperable. Units must therefore agree on a version
before use.
The data rate is very slow and tracks may only be updated
approximately every 6 mins.
Standards
STANAG 5514
SOPs
ADatP-14
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Link 11 (TADIL A)
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Link 11, sometimes called Link 11A (Tactical Digital
Information Link A (TADIL A)) to differentiate it from Link 11B, is based on
1960’s technology and is a relatively slow link. It is secure, but not ECM-resistant,
and is used widely to exchange digital information among airborne,
land-based, and shipboard systems. It is normally operated in a roll call,
or netted polling, mode under the control of a Data Net Control Station (DNCS).
The DNCS initiates the roll call by addressing and transmitting an
interrogation message to a specific Participating Unit (PU), which then
responds by transmitting its data, while all other stations receive. The
DNCS then interrogates the next PU in the prescribed roll call. Link 11 can
also operate in a broadcast mode where one participant makes a single data
transmission, or a series of single transmissions. Each Link 11 platform has
a Data Terminal Set (DTS) that changes digital computer information into
audio tones for transmission by radio. Link 11 has two waveforms – Conventional
Link Eleven Waveform (CLEW) and Single tone Link Eleven Waveform (SLEW).
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Purpose
Real-time exchange of EW data, and air, surface, and
subsurface tracks and points, together with amplifying data. Transmission of
orders, alerts and commands.
Attributes
Simplex (but may be regarded as half-duplex).
Parallel, Netted with single NCS.
Broadcast.
Data Rate 1364 or 2250 bps.
Encryption. KG-40/40A.
Standards
STANAG 5511
MIL-STD-6011B
MIL-STD-188-203-1A
OPSPEC-411
UK DTDL-IRS (Part II) – Link 11
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Medium
HF or UHF
CLEW. DTS: AN/USQ-111, MX512P, AN/USQ-125 or
AN/USQ-120.
SLEW. DTS: AN/USQ-125 or AN/USQ-120.
MFL. DTS: AN/USQ-120.
DNL.
S-TADIL A. Full implementation of Link 11A using Satellite
Communication (SATCOM) in place of HF / UHF (different from Link 11B SATCOM).
Format
‘M’ series messages.
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CLEW
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Data is transmitted in two 30-bit frames, each consisting
of 24 information bits and six error detection and correction bits. The
information message is essentially a 48-bit word. A frame is transmitted in
parallel on 15 multiplexed tones. Diversity is available as required by
identical transmissions or independent side band. A 16th tone is reserved
for Doppler correction.
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SLEW
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Data is transmitted in a message format consisting of an
acquisition preamble followed by a header block, a number of data fields, and
End-Of-Message (EOM) field. The preamble resolves Automatic Gain Control (AGC), signal detection, synchronisation, Doppler requirements and equalisation. The header and
data fields use digital procedures for Error Detection And Correction (EDAC) to gain robustness.
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CLEW and SLEW are not compatible waveforms.
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Track No
12 bit Data Link Reference Number (DLRN) (4 digit octal
number, indicating the originating unit, not current tracking unit).
DLRNs correlate with, and may be, mapped onto L16 TNs (but
must be cross referenced to L1 NATO Track Numbers (NTN).
Strengths
Very widely fitted in NATO and beyond, and will remain
operational until at least 2015.
HF ground wave provides BLOS range out to 300nm, but often
unreliable beyond 150nm.
Sky-wave capability can provide reliable ranges in excess
of 600nm.
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SOPs
ADatP-11
ADatP-33
Limitations
The CLEW / SLEW waveforms are incompatible and all PUs
must use the same waveform to achieve connectivity.
Nodal nature makes it vulnerable to loss of DNCS.
Lack of ECM-resistance means it can be rendered inoperative
in a hostile jamming environment.
Cannot handle ground tracks.
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Link 11B (TADIL B)
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Link 11B, sometimes called Serial Link 11, is essentially
a point-to-point version of Link 11 (TADIL A), but its implementation differs
slightly in some areas. For instance, Link 11B includes a unique message to
monitor the status of its link and it does not implement some messages
concerned with ASW data. Link 11B is typically used to disseminate a track
picture between ground units in the same way as Link 1, but it is more
capable and secure.
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Purpose
Real-time exchange of EW data, and air, surface, and
subsurface tracks and points, together with amplifying data.
Transmission of orders, alerts and commands. Free text
available.
Attributes
Duplex.
Serial.
Point-to-point. Pairs of RUs operate on separate LINK 11B channels often referred to as B links.
Data Rate 600, 1200, 2400, 4800 and 9600bps.
Encryption. (KG-30, KG-84, KG-94A, KG-194A).
Format
‘M’ series messages.
72 bits per message (24 bits overhead and 48 bits of
information) arranged in eight 9-bit frames with:
1 start frame;
6 data frames, each with a mark bit;
1 end check frame with a mark bit.
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Medium
Single or multi-channel radio.
Landline.
Microwave.
SATCOM.
Track No
12 bit DLRN (4 digit octal number).
Standards
STANAG 5511
MIL-STD-6011
MIL-STD-188-212
UK DTDL-IRS (Part II) – Link 11B
SOPs
ADatP-11
ADatP-33
Strengths
ECM-resistant, as is inherent in a buried cable or
microwave link.
Limitations
Cannot handle ground tracks.
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JTIDS
IJMS
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Interim JTIDS Message Specification (IJMS) was developed
to provide an interim operational capability for JTIDS because the JTIDS
hardware was available before the Link 16 message standard. IJMS is based on
Link 11 messages, packaged to fit into the JTIDS architecture. Consequently,
it has the same functionality as Link 11, but with greater security, speed
and EPM. It also provides secure voice communications, but it is not
optimised for the JTIDS architecture and so it cannot use the enhanced JTIDS
features that increase data throughput. IJMS usually operates on a network
shared with Link 16, for which capacity is allocated by assigning time slots
to IJMS participants in the same way as for Link 16 units. IJMS is still
used by NATO but message standards are no longer maintained.
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Purpose
Exchange of EW data, points, air, surface and subsurface
tracks, with amplifying data. Free text and ECM Resistant Voice (ERV), reduced
C2 capability providing digital control and related command and exchange of
weapons status information.
Attributes
Netted Time Division Multiple Access (TDMA) architecture.
Frequency hopping through 51 discrete frequencies.
Spread spectrum.
Encrypted (KGV-8).
Keying Devices KYK-13 or AN/CZY-10.
Data Rate 26,000 bps.
Format
‘C,I, N, P, S, T’ series messages.
225 bits per message.
Track No
15 bit System Track Number (STN) (5 octal digits).
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Medium
Upper UHF (960-1215 MHz).
Terminals
JTIDS Class 1 – Hughes Improved Terminal (HIT) (also known as ECM Resistant Communication System (ERCS)). JTIDS Class 2 - bilingual models
(some Class 2 terminals only allow JU to synchronise with IJMS).
Standards
Now withdrawn or dormant.
Strengths
No critical nodes once network is established. Can be
used by Link 16 JUs for time synchronisation.
Limitations
JTIDS Class 1 terminals are not capable of operating on
Link 16.
Some (but not all) JTIDS Class 2 platforms can operate on
IJMS and Link 16 concurrently.
SOPs
ADatP-16 contain some IJMS procedures.
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MIDS
/ JTIDS Link 16 (TADIL J)
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MIDS describes NATO need for a secure, high capacity,
ECM-resistant communications link designed for all environments (space, air,
surface and land) and all platform types (including both C2 and non-C2 units).
Based on 1970s technology, the requirement was originally fulfilled by
hardware called JTIDS, but newer terminals called MIDS Low Volume Terminal (LVT)
also exist. Utilising time division architecture, Link 16 JUs have
pre-assigned sets of multiple time slots in which to transmit their data and
to receive data from other units. The time slots of a net can be parcelled
out to one or more Network Participation Group (NPG), which are defined by
operational function and by the types of messages that will be transmitted in
it. Link 16 is one of two message standards that may be carried on MIDS /
JTIDS, the other being IJMS.
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Purpose
Exchange of EW data, points, lines, areas, air, space,
surface, subsurface and land tracks, with amplifying data, in real-time.
Navigation and identification data, free text, ERV,
transmission of orders, alerts, commands and status data. Digital ac control.
Attributes
Netted TDMA architecture.
Frequency hopping through 51 discrete frequencies.
Spread spectrum.
Encrypted (KGV-8, CDH).
Keying Devices KYK-13 or AN/CZY-10.
Nodeless multi-netting support for up to 127 nets (but
practical limit is stated to be 20).
Medium
Upper UHF (960-1215 MHz).
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Terminals
JTIDS Class 2/2H .
AN/URC-138.
MIDS LVT 1 (standard terminal).
MIDS LVT 2 (US Army version).
MIDS LVT 3 (F15 FDL).
MIDS LVT 4 – 10 (LVT 1 platform variants - see ADatP-33).
Packing
Standard Double Pulse. Three words, preceded by
EPM jitter, time synchronisation and refinement and message header, 500nm
propagation available.
Packed 2 Single Pulse. Six words, with EPM jitter
500nm propagation available.
Packed 2 Double Pulse. Six words, no EPM jitter
300nm propagation only.
Packed 4 Single Pulse. Twelve words, no EPM jitter,
300nm propagation only.
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Format
‘J’ series messages.
Messages
Made up of one or more of three types
of 75-bit words (all starting with 2-bit word format label and ending with
5-bit parity check, the remainder being the fields described below):
Initial Word
5-bit label, 3-bit sub-label, 3-bit message length
indicator, 57-bit data.
Extension Word
One to four words, 68-bit data.
Continuation Word
One to 31 words, 5-bit continuation label, 63-bit data.
Strengths
Large and comprehensive message catalogue.
No critical nodes once network is established.
Relay, with up to five dedicated hops, may be designed
into the system to achieve BLOS performance, but facility uses data capacity.
Message Packing increases data capacity, but at expense of
EPM.
Precise Participant Location & Identification (PPLI)
messages provide crypto-secure positive identification.
Two modes of establishing grid position available:
Relative grid when relative navigation is provided by measuring Time Of Arrival
(TOA) of signals from each terminal; JUs update their geodetic position using
data from the position of a terminal acting as
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Navigation
Controller. For Geodetic Grid terminals use geodetic position derived from GPS. TOA data is still calculated but a navigation controller is not active. GPS is the more accurate and preferred method.
Track No
19 bit STN (Two character alpha numeric – 5-bits each, 0-7
or A-Z, but not I and O – and 3 octal digits, 3-bits each).
Standards
STANAGs 5516 and 4175.
MIL-STD-6016C.
UK DTDL-IRS (Part II) – Link 16.
SOPs
ADatP-16
ADatP-33
Limitations
High capacity requirement constrains link to a UHF
solution, range limited to direct LOS (300nm normal mode or 500nm extended).
All participants synchronise on Network Time Reference
(NTR) on network entry, but once synchronised, network can operate for only a
few hours without NTR.
System shares frequency band of some flight navigation
systems (notably DME / TACAN) - permission required from civilian ATC
authorities to operate.
MIDS / JTIDS network design is a complex activity and
configuration details must be disseminated to all participants before
operations can commence.
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Clearance to operate MIDS / JTIDS within the UK Flight
Information Region (FIR) is administered by the JDLMO Data Link Management Cell
(DLMC), UK CAOC, RAF High Wycombe; Monitoring of the UK Frequency Clearance
Agreement with the CAA is undertaken by the JDLMO.
MIDS / JTIDS networks operating in the UK are planned, designed and disseminated by the JDLMO Network Design Cell (NDC) using the TDL
Network Design System (TNDS).
MIDS / JTIDS Network Participation Groups
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NPG‑1 Network Entry
NPG‑2 RTT-A
NPG‑3 RTT-B
NPG‑4 Network Management
NPG‑5 PPLI A
NPG‑6 PPLI B
NPG‑7 Surveillance
NPG‑8 Mission Management / Weapons Coordination
NPG‑9 Control
NPG‑10 Electronic Warfare
NPG‑11 Not used by US platforms
NPG‑12 Voice A
NPG‑13 Voice B
NPG‑14 Reserved joint use (USN Indirect
PPLI Interim Use Only)
NPG‑15 Reserved joint use (THAAD Interim
Use Only)
NPG‑16 Reserved joint use (THAAD (Interim
Use Only)
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NPG‑17 Not used by US platforms
NPG‑18 Reserved joint use (USN
Interim Use Only)
NPG‑19 Fighter-to-Fighter A
NPG‑20 Fighter-to-Fighter B
NPG‑21 Engagement
NPG-22 Composite A
NPG‑23 Composite B
NPG‑24 Not used by US platforms
NPG‑25 Reserved joint use (THAAD
Interim Use Only)
NPG‑26 Not used by US platforms
NPG‑27 Joint Net PPLI
NPG‑28 Distributed Network
Management
NPG‑29 Residual Messages
NPG‑30 IJMS P Message, Position
NPG‑31 IJMS T Message, Track Report
NPG‑32 to 511 USA Need Lines
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NB: An ‘Interim Use
Only’ NPG is not approved for joint use.
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Qt / Qp Table
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Time Accuracy
nanoseconds
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Quality
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Position Accuracy
feet
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<50 (NTR)
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15
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<50
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<71
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14
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<71
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<100
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13
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<100
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<141
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12
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<141
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<200
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11
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<200
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<282
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10
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<282
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<400
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9
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<400
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<565
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8
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<565
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<800
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7
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<800
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<1130
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6
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<1130
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<1600
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5
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<1600
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<2260
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4
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<2260
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<4520
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3
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<4520
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<9040
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2
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<9040
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<18080
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1
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<18080
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>18080
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0
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>18080
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CPD Table
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Leap Year CPD Prediction Tables
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2008
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2004
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Month
|
Day
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Month
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Day
|
|
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Odd
|
Even
|
|
Odd
|
Even
|
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January
|
0
|
1
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January
|
1
|
0
|
|
February
|
1
|
0
|
February
|
0
|
1
|
|
March
|
0
|
1
|
March
|
1
|
0
|
|
April
|
1
|
0
|
April
|
0
|
1
|
|
May
|
1
|
0
|
May
|
0
|
1
|
|
June
|
0
|
1
|
June
|
1
|
0
|
|
July
|
0
|
1
|
July
|
1
|
0
|
|
August
|
1
|
0
|
August
|
0
|
1
|
|
September
|
0
|
1
|
September
|
1
|
0
|
|
October
|
0
|
1
|
October
|
1
|
0
|
|
November
|
1
|
0
|
November
|
0
|
1
|
|
December
|
1
|
0
|
December
|
0
|
1
|
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Non Leap Year CPD Prediction Tables
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2006, 2009
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2005, 2007, 2010
|
|
Month
|
Day
|
Month
|
Day
|
|
|
Odd
|
Even
|
|
Odd
|
Even
|
|
January
|
0
|
1
|
January
|
1
|
0
|
|
February
|
1
|
0
|
February
|
0
|
1
|
|
March
|
1
|
0
|
March
|
0
|
1
|
|
April
|
0
|
1
|
April
|
1
|
0
|
|
May
|
0
|
1
|
May
|
1
|
0
|
|
June
|
1
|
0
|
June
|
0
|
1
|
|
July
|
1
|
0
|
July
|
0
|
1
|
|
August
|
0
|
1
|
August
|
1
|
0
|
|
September
|
1
|
0
|
September
|
0
|
1
|
|
October
|
1
|
0
|
October
|
0
|
1
|
|
November
|
0
|
1
|
November
|
1
|
0
|
|
December
|
0
|
1
|
December
|
1
|
0
|
Link 22
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Originally called NATO Improved Link Eleven (NILE) and
predominantly designed for maritime forces, Link 22 is planned as a secure,
ECM-resistant, medium speed replacement for Link 11 that will work in harmony
with Link 16. It has similar message capabilities to Link 16, but with
extended BLOS capability (which is achieved at the expense of data
throughput). Tactical data may be exchanged selectively among NUs within
communities of interest, which are defined by functional requirements. All
NUs will be capable of single network operation, but some will be able to
communicate on up to four Mission Area Sub Networks (MASN) simultaneously,
either using the same or a combination of media. A set of interconnected
networks is known as a Super Network.
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Purpose
Exchange of EW data, air, space, land, surface &
subsurface tracks and points, with amplifying data in real-time.
Transmission of orders, commands and alerts between C2
systems.
Attributes
TDMA or dynamic TDMA.
Spread spectrum.
Frequency hopping.
NILE Link Level Crypto (LLC).
Data Rate better than Link 11, but less than Link 16.
Format
‘F’ and ‘F/J’ series messages (‘F/J’ messages are ‘J’
messages with 2 additional bits of overhead).
72 bits per message.
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Track No
19 bit STN (Two character alpha numeric – 5-bits each, 0-7
or A-Z, but not I and O – and 3 octal digits, 3-bits each).
Medium
HF (2 - 30 MHz) and UHF (225 - 400 MHz), simultaneously on
different networks using either fixed or frequency agile waveforms.
Standards
STANAG 5522
SOPS
ADatP-22
ADatP 33
Strengths
Gapless coverage > 300nm range on HF. Relay may
increase geographic coverage of HF > 1000 nm and UHF > 300nm.
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VMF
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VMF has its origins in a 1970s US Army requirement for a
variable message extension to Link 16 and is primarily aimed at ground
operations fire support. Although it will also support many other
operations, it is not intended as a surveillance picture compilation link. Sometimes
erroneously called Joint VMF, VMF messages are designed as a common means of
exchanging digital data between combat units at various organisational
levels. With the flexibility to accommodate varying needs for volume and
detail, VMF messages may be applied to a broad range of tactical
communication systems. VMF is bearer-independent, although most current
users employ a Combat Net Radio (CNR) compatible system.
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Purpose
Real-time data exchange for Fire Support, and Close Air
Support (CAS). No real-time Situational Awareness (SA) but has Blue Force
tracking capability. Many other army based functions.
Attributes
Can be transmitted in either secure or non-secure mode. Effective
throughput varies with medium in use: typically 2,400 bps, 4,800 bps or 9,600
bps using different generation VHF radios, or 16,000 bps using landline.
Format
‘K’ series messages.
VMF is bit-oriented but can use character-oriented
elements. Message lengths may vary.
Medium
Network functions independent of textual portion of
message thus VMF is media independent and can operate over any digital
point-to-point or network architecture broadcast capable radio system.
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Messages
Uses predefined fixed length fields and employs a header
extension and internal syntax to specify the presence, absence and recurrence
of fields, as selected by user.
Header Information
Originator Address Group.
Recipient Address Group.
Information Address Group.
Message Handling Group.
Originator Date/Time/Group.
Perishability Date/Time/Group.
Acknowledgement Request Group.
Response Data Group.
Version Number.
Compression Type.
Message ID Address Group.
Reference Message Group.
Date Time Group Extensions.
User Data
Data Field Indicator.
Data Use Indicator.
Data Item.
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Strengths
Achieves higher effective data flow
by more efficient use of message space than other types of TDL.
Provides user with flexibility to send specific
information only, on demand, and is thus suitable for use in bandwidth
constrained environments.
Standards
MIL-STD-6017 (K-series messages).
MIL‑STD‑188‑220 (CNR protocols).
MIL‑STD‑2045‑47001 (Message header).
MIL‑STD‑2045‑14502 Ch1/6.
Reference Documents:
US VMF IOP
Part of the JMTOP. Provides guidance on how VMF systems
should be used in the US.
UK VMF Users Guide (VUG)
This UK Unclassified comprehensive guide has been
developed for the novice and the systems implementer alike. The guide covers:
the communications bearer, messages and their headers, network management,
data forwarding and hardware and equipment issues.
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UK Single
Link Interface Requirement Specification (SLIRS)
SLIRS describes in a user friendly manner, the way that the
K-series messages and the MIL-STD-2045-47001 message header are to be
implemented by UK platforms. It also describes related issues such as the
Tactical Internet interoperability, and network planning and management.
UK System Management and Operating Procedures
(SMOPS)
This UK Unclassified document provides general and
specific guidance on how VMF systems should be operated.
UK Bearer Definition Document (BDD)
This technical document provides direction on the
implementation of MIL-STD-188-220.
Limitations
Interoperability problems because of the huge degree of
options available.
VMF is widely used by US Army, USMC, and USN but not by
USAF, who intend to develop a Link 16 / VMF gateway.
UK plan to use VMF on the GR4A/4A, GR9/9A, Joint Strike
Fighter (JSF), FAC and potentially many other platforms associated with ‘land
related missions’.
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Other Links
Air Force Applications Program Development (AFAPD)
The AFAPD message protocol was developed in the late 1970s
as part of the USAF Ground Digital Communications Terminal System (GDCTS)
development effort. The GDCTS program started as a joint (US Air Force (USAF)
and US Marine Corps (USMC) effort, but differences in requirements led to two
different programs. The USAF went with AFAPD and the USMC developed Marine
Tactical System (MTS)
Current fielded versions of AFAPD are generally in two,
non-interoperable, categories:
·
US Army Helicopter AFAPD - this is Boeing proprietary and is
fitted to any Boeing platforms as a ‘take it or leave it’ package.
·
USAF and NATO F16 AFAPD -this is the USAF AFAPD and is not
proprietary.
AFAPD operates with a CNR as well as wire / cable
communications mediums. The protocol allows for up to 127 addressees within a
single network, i.e. each net can have up to 127 subscriber IDs with any 15 of
those active at a given time. Each subscriber can be entered into as many as eight
nets. Messages can be sent to specific addressees or a unique ‘global address’
may be used for network-wide transmissions. Both direct and indirect
addressing is used. Direct addressing is used to send a message to a specific Digital
Message Transfer Device (DMTD) within the network. Indirect addressing is used
to relay messages between intermediate DMTDs. Relay addresses must be set in
the intermediate DMTDs prior to operation. This means that the relay units
must have a prior knowledge of the destination addresses. Messages may be
relayed up to seven times.
AFAPD also has an acknowledgement function that is used to
verify a message has been received at the destination DMTD. This capability is
optional on a message-by-message basis. When a message is relayed, the
protocol only provides acknowledgement from the first relay DMTD, not the final
recipient. The AFAPD protocol uses both (12,23) Golay Coding and Time
Dispersal Coding (TDC) Forward Error Correction (FEC) techniques.
The AFAPD message set includes both formatted and free text
messages. Messages are predominately text (ASCII character) oriented as
opposed to the bit-oriented message standards such as Link 16 and VMF. Some
newer AFAPD platform integration efforts have developed new messages that are
bit oriented, but these are limited.
The AFAPD protocol allows for data rates ranging from 75 to
16,000 bps. This, however, may be limited by the CNR used. The actual data
rate is affected by the applicable CNR, cryptography equipment used, and AFAPD
message header overhead.
ATDL-1
Army Tactical Data Link-1 (ATDL-1) is a secure,
point-to-point, full duplex data link, utilising serial transmission frame
characteristics and standard message formats. The link operates at the basic
rate of 1200 bps, with an alternate rate of 600 bps, and has optional rates of
2400 or 4800 bps. ATDL-1, which supports data exchange between tactical air
control units and Surface-to-Air Missile (SAM) systems, can be transmitted over
a variety of media, such as cable, satellite, and single or multi-channel radio
links. Utilising ‘B’ series messages, the transmission characteristics and
standards for ATDL-1 are described in MIL‑STD‑6013A (U) and MIL‑STD‑188-212.
Used by: USMC Tactical Air Operations Centre (TAOC), USAF (Control
and Reporting Centre(CRC) / Control and Reporting Element (CRE), Iceland Air Defence System (IADS)), US Army (Patriot, Theatre Missile Defence (TMD) Tactical
Operations Centre (TOC)), NATO (Belgium, Denmark, Germany, Greece, France,
Italy, Netherlands, Norway, Turkey) and Other Nations (Egypt, Iran, Iraq,
Israel, Jordan, Korea, Kuwait, Saudi Arabia, Taiwan).
Air Command and Control System (ACCS)
Wide Common Information Standard (AWCIES)
NATO ACCS has been designed to replace the NATO Air Defence
Ground Environment and similar systems. Data communication between ACCS sites
will be achieved by use of new exchange standard, base on Link 16, called
AWCIES.
CDL / TCDL / HIDL
In 1991, the US DoD designated Common Data Link (CDL) as its data link standard for imagery and signal intelligence. CDL consists of a secure,
jam resistant uplink operating at 200 kbps, and a downlink that can operate at
10.71 Mbps, 45 Mbps, 137 Mbps or 274 Mbps, but currently only the first of
these downlink rates is secure. CDL also permits the remote operation and
exploitation of a platform’s sensor from BLOS locations via satellite. The CDL-compliant Tactical Common Data Link (TCDL) programme will provide a family of interoperable,
secure, digital data links for use with both manned and unmanned airborne reconnaissance
platforms. TCDL will transmit radar, imagery, video and other sensor
information at rates from 1.544 Mbps to at least 10.7 Mbps, over ranges of up
to 200km, but it will also soon be able to support the higher CDL rates. CDL and TCDL will be used in the ASTOR and Reconnaissance Airborne Pod for Tornado (RAPTOR)
programmes, but the UK is also evaluating a High Integrity Data Link (HIDL) for
UAVs that will be able to operate with wideband TCDL. Operating at 225-400 MHz
(UHF) and 100 Kbps bandwidth, HIDL will be a full-duplex narrow-band
jam-resistant data link. Consisting of airborne and surface-based terminals,
HIDL will operate in broadcast mode to control at least two UAVs simultaneously
out to ranges of 200 km.
CEC / Joint Composite Tracking Network (JCTN)
Whilst not a TDL in the traditional sense, CEC is a plot data exchange system designed to produce an air picture which is real-time and of
sufficient accuracy and quality. This allows the weapon system of one maritime
platform to engage objects without itself necessarily having local sensor data.
It also has the potential for broader warfare applications. The US is therefore expanding CEC to embrace all aspects of the air battle through the JCTN.
CEC is a ‘plot fusion’ system with extreme high data rates
of 2 - 5 Mbps (to be enhanced to 10 Mbps) and provides the means for sharing sensor
assets among multiple units in a counter-measures environment to perform
detection or surveillance, control and engagement functions. CEC makes cooperative use of all participants plot measurements to produce a single, shared
picture. CEC units are equipped with omni-directional beacon antennas, which
allow for directed LOS data exchange at ranges of approximately 50-60 km. In
essence, CEC allows one platform to track an object and another unit to engage
it. It also provides good ECM protection.
The CEC network will not replace Link 16 or Link 22 in the
integrated battle area, although plans exist for further implementation and
development. For the foreseeable future, CEC and traditional TDLs will
continue to complement each other. CEC is planned for integration into most USN
aircraft carriers, some command ships, AEGIS cruisers, Arleigh Burke destroyers
and E-2C 2000 AEW ac. It may be fitted to US Army Patriot and probably Theatre
High Altitude Area Defence (THAAD). Fitting to USAF E-3 aircraft and the USMC
AN/TPS-59 radars is also likely. The RN T45 destroyer is planned to be
upgraded with CEC with space and support provision having been made.
Fighter Data Link (FDL) (USAF)
FDL (USAF) is fitted to US F15 C/D and F15E aircraft. The
FDL terminal has a lower power output than other MIDS terminals, does not
provide a voice capability or a relay function.
FORMETS / Message Text Format (MTF)
Known within the US as MTF, FORMETS provides uniform report
formats and procedures to facilitate the exchange of information between allied
units. By producing interoperable character oriented messages that are both
readable by the human and the machine, FORMETS aims to reduce or eliminate dual
reporting. Defined in STANAG 5500 and ADatP-3 (MIL‑STD‑6040 for US MTF), FORMETS is independent of any communications medium. It is widely
implemented and may be used for air and combat operations, intelligence, fire
support and Combat Service Support (CSS) management.
Link 4 (TADIL C)
Link 4 is an insecure, time-division, serial data link,
which utilises serial transmission characteristics and standard message
formats. Used for the automated control of ac, Link 4 provides for the
exchange of track data and the transmission of orders, commands and status, and
can be operated either as a one-way or two-way link between a controlling unit
and controlled ac. Operating in the UHF frequency band at 5000 bps, it supports
US Air Training Command (ATC), air intercept control, ASO, precision course
direction and automatic aircraft landing. Link 4 is used by US forces only and
the largest platform (in terms of numbers) the F14 has now been withdrawn from
service. (Although Link 4 was delivered with the UK E-3D, its implementation
has not been maintained and it is now obsolete).
Joint Range Extension (JRE)
Not a TDL, JRE deals with the LOS problems inherent with
JTIDS / MIDS transmissions. JRE evolved out of Operation DESERT STORM where
the Link 16 picture was relayed back to the JOC using TADIL-B landlines. The
significant differences in transmission rates meant that real-time picture was
often not available or useful to the Command and Control infrastructure. The
development of TMD necessitated the transmission of track data significantly
beyond LOS without incurring any latency issues.
At its simplest level, JRE provides an interface between the
JTIDS / MIDS terminal and long haul communications networks, such as SATCOM.
The interface, which can be standalone or embedded, would perform filtering of
messages, routing to various media, and packaging the Link 16 information for
transmission along with potential administration and overhead messages for the
link processing.
JRE provides a similar function to other LOS solutions such
as Satellite TDL (STDL) but uses a different approach. The application
protocol used is the JRE Application Protocol (JREAP) defined in MIL-STD-3011.
Surveillance and Control Data Link (SCDL)
SCDL is a narrow-band data link used by the E-8C JSTARS for
promulgating its MTI and SAR radar pictures to dedicated ground stations, known
as Common Ground Station (CGS). SCDL uses a robust frequency hopping waveform,
error correction coding and diversity techniques to mitigate jamming. The
network employs a TDMA scheme that can, in real-time, revise network
assignments and priorities. The SCDL also provides an up-link to the Joint
Surveillance Target Attack Radar System (JSTARS) ac for radar service requests
from the CGS. It is intended that SCDL will also be implemented within the
ASTOR.
STDL Link 16 / S-TADIL J
Both the UK and US have the requirement and ability to pass selected
Link 16 messages utilising satellite technology. Unfortunately, these national
systems are presently incompatible, both in format and communication bearer.
Due to enter service in 2006, STDL will no longer be
delivered with the Universal Modem and as such will not be capable of the full Network
(TDMA) Mode of Operation. Instead STDL uses the SLM 6650 modem and is capable
of the Group and Broadcast modes of operation only.
The USN is investing in satellite Link 16 for BLOS data
exchange. Known as S-TADIL J, the USN system utilises organic UHF SATCOM and
supports all Link 16 mission areas except for control (air intercept and
fighter-to-fighter), voice coordination, system information and net
management. S-TADIL J uses the 25 kHz Demand Assigned Multiple Access (DAMA)
system working a roll call protocol and the information exchange process is
controlled by the S-TADIL J control unit.
TACFIRE
TACFIRE was developed as a computer system to conduct fire
support operations. The system included central computer systems to analyse
and process fire requests, as well as smaller hand-held devices to input
messages and transmit over CNRs to higher echelons. The message protocol
developed for this system was also called TACFIRE. The TACFIRE system was seen
as a battlefield integration tool that provides the ability to rapidly format complex
messages such as:
·
Airborne Fire Requests.
·
Artillery Fire Requests.
·
Reports.
·
Emergency Broadcasts.
·
Automatic Status Reporting.
·
Movement Commands.
·
Free text messages.
The original TACFIRE message protocol only supported data
rates of 1,200 and 2,400 bps. The error detection and correction functionality
supported by the TACFIRE protocol is limited, supporting only a (12,7) Hamming
code. The TACFIRE message protocol also allows for information blocks to be
transmitted once or twice helping with the Error Detection and Correction
(EDC). Acknowledgements are also supported by the TACFIRE message protocol.
The TACFIRE message protocol originally used a single
alphanumeric character for addressing purposes (0-9 and A-Z), which limited the
maximum number of TACFIRE network participants to 36 with 10 active at a given
time. Subsequent modifications to the protocol have added a leading 0, 1, or
2, which provide for up to 128 participants. Each subscriber can be entered
into as many as eight nets.
The TACFIRE message protocol by itself is not robust enough
to be used over secure and anti-jam radio equipment. Earlier TACFIRE systems
added a Data Rate Adapter to allow proper operations with VHF / FM Single
Channel Ground-Air Radio System (SINCGARS) CNR radios and cryptographic
equipment.
Integrated Broadcast System (IBS)
IBS will replace the current family of UHF satellite
intelligence broadcast systems, comprising TIBS, Tactical Reconnaissance
Intelligence Exchange Service (TRIXS), Near Real-Time Tactical Dissemination
System (NRTD) and TRAP (which uses the TDDS and TADIXS-B broadcast systems).
It will receive tactical intelligence information from national and theatre
producers, and from tactical ISR systems, and disseminate tactical intelligence
throughout the world via various communications paths (either directly or
through a gateway). In particular, it will process data pertaining to threat
avoidance, threat warning, targeting, manoeuvre, force protection, target
tracking, target situation / awareness, and indications and warnings to
tactical C2, sensor, weapon and ISR systems.
A system-of-systems, IBS will use a single Joint Tactical
Terminal as an interim solution to provide interactive two-way functionality
and to receive up to eight one-way channels. Recently, the Commanders Tactical
Terminal (CTT), Multi-Mission Advanced Tactical Terminal and Tactical Receive
Equipment (TRE) receiver programs have been migrated towards this standard,
which will continue under IBS to develop Common IBS Modules, with emphasis
being placed on preserving the features required by a varied user community.
IBS will use the TIBS Revision ‘E’ messages as its single
common Over-The-Air format, to which TRAP Data Transmission System (TDDS),
TIBS, TRIXS and TADIXS-B have already converted. In the near term, data and
operational coordination circuits will be established between TDDS and TIBS,
together with a gateway to permit the exchange of TRIXS and TIBS data. IBS
will employ multiple communications paths, with UHF satellite broadcasts being
used for high priority messages (such as immediate targeting information,
threat warning and threat avoidance) and SHF satellite broadcasts being used to
support routine message exchange.
Until
2007, a gateway will be used to forward IBS message strings to TADIL J and VMF
networks, but IBS will not participate directly on these links.
TDL Summary
|
Link
11
|
MIDS
/ JTIDS Link 16
|
STDL
Link 16
|
Link
22
|
|
Operating Frequency
|
HF/UHF
Fixed frequency
|
UHF
969-1206 MHz
|
SHF
|
HF/UHF
Fixed freq / freq. agile
|
|
Data Rate (Nominal)
|
2.25 kbps
|
57.6 kbps (at moderate ECM resistance)
|
19.2 kbps
|
1.4 or 4 kbps (HF)
12.7 kbps (UHF)
|
|
Max. No. of Participants
|
56 (theoretical) active PUs
Unlimited receive only
|
Unlimited
(practical limit 240)
|
15 transmit, 30 receive
|
120
|
|
Throughput Measure - Nominal
|
20 tracks per 10 sec net cycle
|
75 tracks per 12 sec (at moderate ECM resistance)
|
30 tracks per 12 seconds
|
30 tracks per 10 seconds per user
|
|
Coverage - Range
|
HF: variable, 300 nm nominal
UHF: LOS
|
LOS
|
Near-world-wide satellite footprint
|
HF: variable, 300 nm nominal
UHF: LOS
|
|
Nodal
|
Yes
|
No
|
Yes (requires ground station)
|
No
|
|
Jam Resistance
|
Zero
|
Excellent
|
Good
|
Reasonable
|
|
Error Resistance
|
Poor
|
Excellent
|
Excellent
|
Good
|
|
Robustness
|
Poor - nodal polled system
|
Excellent – non-nodal
Relay available
|
Medium - reliant on satellite resources
|
Good – non-nodal
Relay available
|
|
Message Structure
|
M-Series
Little scope for growth
|
J-Series
Good Granular Accuracy
|
J-Series
Good Granular Accuracy
|
F, F/J-series
|
|
Max Track Accuracy Reportable
|
Air ± 5 dm
Surface ± 0.5 dm
|
± 0.01 dm (± 60 ft)
|
± 0.01 dm (± 60 ft)
|
± 0.01 dm (± 60 ft)
|
|
Major Weaknesses
|
Nodal, old technology, no jam-resistance, high probability
of intercept and exploitation
|
Line of Sight unless airborne relay available, frequency
clearance restrictions
|
Competition for satellite resources, high probability of
intercept. RN only
|
Limitations of HF radio communications, medium probability
of intercept
|
|
Major Strengths
|
In service with all NATO nations
|
High capacity, ECM resistant, low probability of intercept
and exploitation, fitted to fighter ac
|
Long-range, ECM resistant, potential of very high data
rate, low probability of exploitation
|
Modern networking techniques, simple radio technology, low
probability of exploitation
|
TDL Platform Capability Summary
|
UK Forces[1]
|
Allied Forces[2]
|
|
Link 1
|
|
ITACC (ASE)
UK ASACS, ADLBS,
Ship Shore Ship Buffer (SSSB) TACC
|
USAF
CRC/CRE, IADS
USN
SSSB
Other Nations
AEGIS, GEADGE, NADGE, SPADA, STRIDA
USMC
TACC, TAOC
|
|
Link 11 (TADIL
A)
|
|
ALES (Rx Only)
CVS Aircraft Carrier
E3-D Sentry AEW 1
ITACC (MDLT)
JFAC HQ
LPH (Ocean - Rx only)
Nimrod MR2
TACC
Type 22/23 Frigate
Type 42 Destroyer
UK ASACS (ADLBS, SSSB)
UK CAOC (ROLE – Rx Only)
Merlin (CLEW only)
LPD (Albion and Bulwark)
Planned:
Nimrod MRA4
Astute/Trafalgar/Swiftsure SSN
Type 45 Destroyer
|
USAF
AOC, CRC/CRE, AWACS, Rivet Joint, Senior Scout, Senior
Troupe, RADIC, RAOC/SAOC, U2 DCGS, IADS, PROC.
USN
CV, CG, DDG, FFG, LHA/LHD, LCC, SSN, E2C, EP‑3, ES‑3,
P‑3C, S-3.
USMC
TACC, TAOC, TERPES
US Army
Patriot, TMD TOC
|
|
Link 11B (TADIL
B)
|
|
UK ASACS (via Link 1 / 11B buffer between Buchan and Iceland).
UK ASACS (SSSB)
|
USAF
AOC, CRC/CRE, IADS, RAOC/SAOC, U2 DCGS, IADS, RADIC, ASIT,
Senior Troupe
USMC
TACC, TAOC, MATCALS, TERPES
US Army
Patriot, FAADC2I, THAAD, TMD TOC.
Other Nations
NATO CRCs, AN/TSQ‑73 radars
|
|
UK Forces
|
Allied Forces
|
|
JTIDS IJMS
|
|
E3-D Sentry AEW 1
UK ASACS (ADLBS)
UK CAOC (JTIDS Air Platform Network Management System
(JAPNMS) - network management only).
|
USAF
E-3B/C
Other Nations
E-3A
E-3F
NATO CRCs
|
|
Link 14
|
|
E3-D Sentry AEW 1
UK ASACS (CRC - Rx only, SSSB)
|
Other Nations
Many NATO smaller surface units
|
|
MIDS / JTIDS
Link 16 (TADIL J)
|
E3-D Sentry AEW 1 (JTIDS Class 2H).
Tornado F3 (JTIDS Class 2)
UK CAOC (JAPNMS - network management only)
CVS (JTIDS Class 2H)
Type 42 DDG(JTIDS Class 2H)
Nimrod R (JTIDS Class 2)
Sea King ASaC MK7 (UK/URC-138)
Tristar (UK/URC-138)
RAP Troop (UK/URC-138)
Type 22, Type 23 FFG, LPH and LPD (Link 16 Standalone
Capability (UK/URC-138))
Situational Awareness for 16AAB
Planned:
ASTOR ((UK/URC-138))
Eurofighter (MIDS LVT 1)
Nimrod MRA4 ((UK/URC-138)
SSN
TJF (JTIDS Class 2) (2005)
Type 45 (JTIDS Class 2H)
UK ASACS (ACCS) (2011)
|
USAF
AOC, CRC/CRE, AWACS, JSTARS, Rivet Joint, ABCCC, F‑15C/D/E,
U2 DCGS, B-1, B-2, B-52, TACP, ASOC
Planned: RAOC/SAOC, ABL, IADS, F‑16, OA-10, F22,
F-117, JSF
USN
CV, CG, DDG, LHD, LHA, SSN, F‑14D, F/A‑18, E2C, EP3
Planned:, LCC, JSF
USMC
TAOC, ADCP, TACC, F/A‑18
Planned: JSF
US Army
Patriot, FAAD C2I, THAAD, TMD TOC, M3P(JTAGS)
Planned: MEADS, AH-66
Other Nations
E-3F, FAF E-2C, Patriot
Planned: Rafale, Erieye (Greece), JSF
|
|
STDL Link 16 /
S-Link 16
|
|
CVS
Type 23
Type 42
Planned:
Astute/Trafalgar/Swiftsure SSN
Type 45
|
|
UK Forces
|
Allied Forces
|
|
Link 22
|
|
Possible:
CVS
Type 23 FFG
Type 42 DDG
Type 45 DDG
|
USN
Planned: C2P equipped ships
Other Nations
Planned: Canada, France, Germany, Italy, Netherlands
|
|
VMF
|
|
Planned:
FAC
Harrier GR9
Tornado GR4
JSF
|
USAF
Planned: TACP
USN
F/A-18
Planned: AFATDS, EA-6B
USMC
F/A-18, TACC, TCO, AFATDS, IAS, BCS, TCAC, TRSS, DACT,
TLDHS, , TAOC, DASC, TERPES, MATCALS, GCCS, MEWSS, TPCS, MIPS, MDSS, MMS, TPQ-36, MCSSC2S, RTU
Planned: AH-1Z, AV‑8B, V-22, UH‑1Z, CV‑22
US Army
AH-64, FAADC2I, AFATDS, BCS, MLRS, IFSAS, FED, TPQ-36/37, M1 Tank, M2 APC, UH-60, OH-58, MBC, MMS, and JSTARS CGS
Other Nations
Planned: Australia
Interest: Canada, Italy, Spain, Norway, South Korea, JSF nations
|
|
Link 4 (TADIL C)
|
|
E3-D Sentry AEW 1 (fitted, but not maintained and now
obsolete).
|
USAF
CRC/CRE, AWACS
USN
CV, CG, DDG, LHA/LHD, LCC, E2C, EA‑6B, ES-3, S‑3,
C-2
USMC
TAOC, F/A‑18, EA‑6B, MATCALS
|
|
|
