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INTRODUCTION TO JTIDS/MIDS LINK 16. JTIDS. MIDS. Joint Tactical Information Distribution System. Multifunctional Information Distribution System. TERMINOLOGY. INFORMATION - sensors, navigation, status, commands, vectors, position DISTRIBUTION - via Link-16
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INTRODUCTION TO JTIDS/MIDS LINK 16
JTIDS MIDS Joint Tactical Information Distribution System Multifunctional Information Distribution System TERMINOLOGY INFORMATION - sensors, navigation, status, commands, vectors, position DISTRIBUTION - via Link-16 SYSTEM - Platforms joined in a tactical environment C.1.2
TERMINOLOGY • JTIDS/MIDS refers to the communications equipment necessary to exchange Link 16 messages • This includes: • Terminal hardware and software • RF equipment • Resulting waveform generated
ENVIRONMENTS Air Surface Subsurface Land Space
IJMS Interim JTIDS Message Standard Bases on Link 11 M-Series messages Adapted to utilise basic JTIDS architecture Class 1 or Bilingual Terminals
LINK 16 • Message standard (STANAG 5516) • 256 combinations of label and sub-label • Link 16 messages support: • Surveillance • Network Management • Control • EW • Voice • Free text messaging
TECHNICAL CHARACTERISTICS L Band UHF 51 Frequencies 969 to 1206 Mhz @ 3 Mhz Intervals
IFF Filters 14 Frequencies 32 Frequencies 5 Freq’s 960 1030 1215 1090 TACAN / DME Channels spaced every 1 MHz 969 1206 Link-16 Frequencies spaced every 3 MHz (51 Frequencies)
ARCHITECTURE • JTIDS/MIDS Link-16is a data link that is: • Real Time • Secure • ECM Resistant • High Capacity • Non-Nodal
ARCHITECTURE • Broadcast type system • each unit can receive directly from all other assigned units • No critical nodes • if one terminal goes down, the network is not crippled
ARCHITECTURE • Time Division Multiple Access (TDMA) • Time is divided into 128 time slots per second • Each terminal can either transmit or receive
EPOCH = 12.8 mins = 98304 Timeslots 1Timeslot = 7.8125 ms DAY (24 Hours) = 112.5 EPOCHS EPOCH = 64 FRAMES 1 FRAME = 12 Seconds FRAME = 1536 Timeslots
ARCHITECTURE • Each time slot is allocated to a specific user for transmission. All other users receive in that time slot.
TIMESLOT Timeslot equates to 7.8125msec 1536 timeslots in 12 seconds Timeslot comprises several components
TIMESLOT • Number of elements within a timeslot • Jitter • Synchronisation • Time refinement • Message header and data • Propagation
JITTER SYNC HEADER DATA PROPAGATION 7.8125 milliseconds TIME SLOT STRUCTURE Jitter - variable time delay in the start of a transmission of a time slot; standard double pulse and packed-2 single pulse message packing structures
TIME SLOT STRUCTURE Synchronization - a pattern of pulses that allows the receiving terminal to synchronize to the transmission JITTER SYNC HEADER DATA PROPAGATION 7.8125 milliseconds
TIME SLOT STRUCTURE Time Refinement - used for Class 1 compatibility only JITTER SYNC HEADER DATA PROPAGATION 7.8125 milliseconds
TIME SLOT STRUCTURE Header - 35 bit word providing information concerning the message(s) transmitted in the time slot JITTER SYNC HEADER DATA PROPAGATION 7.8125 milliseconds
TIME SLOT STRUCTURE Data - message(s) transmitted in the time slot; 3, 6, or 12 TADIL J words, depending on packing structure JITTER SYNC HEADER DATA PROPAGATION 7.8125 milliseconds
TIME SLOT STRUCTURE Propagation - time period to allow the signal to propagate to 300 or 500 NM prior to start of next time slot JITTER SYNC HEADER DATA PROPAGATION 7.8125 milliseconds
TIMESLOT • Header and Data • Link 16 message words taken in groups of: • 3 words (Std) • 6 Words (P2) • 12 Words (P4) • Header specifies: • Message Type • Coding • Packing |Structure • Source terminal
STANDARD PACKING STRUCTURE TIME SLOT 7.8125 MILLISECONDS S TR H DATA PROPAGATION JITTER 3.354 MILLISECONDS 4.4585 MILLISECONDS MINUS JITTER S = SYNCHRONISATION TR = TIME REFINEMENT H = HEADER
ACCESS METHODS • Dedicated • Guaranteed reception • Inflexible • Contention • Flexible • Reception uncertainty • Time slot re-allocation • Shared Pool • Unit requests share
ECM RESISTANCE Double Pulse Jitter Frequency Hopping Crypto variable Encoding Message Preparation
SECURITY • Message Security (MSEC) • Transmission Security (TSEC) • Common Variable Mode • Partitioned variable mode • Auto rollover
MESSAGE PREPARATION • Message Packets • Reed-Solomon encoding • All J-Series Fixed Format words • Interleaving • CCSK • Random Noise
NETWORK ENTRY • Network Time Reference (NTR) • First Platform in net • Transmits Initial Entry Message (IEM) every 12 seconds
NETWORK ENTRY • Platform other than NTR required to synchronise
Estimate of current system time Estimate of time of next entry time slot Time error to within propagation time (clock correction) Time uncertainty Time Slots belonging to Net Entry Time Slot Block A-0-6 Coarse Synchronization will take place using this time slot NET ENTRY
FINE SYNCHRONISATION • Actively or passively • Passively utilising received PPLI’s • Actively • RTT(A) or RTT(B) • RTT (A) Dedicated • RTT (B) Contention
MULTINETTING JTIDS provides the capability to operate simultaneously in up to 127 nets in the same network A terminal can operate (transmit or receive) in only one net in any one time slot but can operate in any net in any time slot as determined by assignment These nets use independent frequency hopping patterns with the net number a variable in determining the hopping pattern
MULTINETTING NET 127 NET ... NET 2 NET 1 NET 0
NETWORK PARTICIPATION GROUPS Previous links, data received and processed if applicable to a platforms role or not NPG’s allow for grouping of J-series messages into a functional role Aids network design
1 INITIAL ENTRY • 2 RTT-A • 3 RTT-B • 4 NETWORK MANAGEMENT • 5 PPLI & STATUS GROUP A • 6 PPLI & STATUS GROUP B • 7 SURVEILLANCE • 8 MISSION MANAGEMENT • 9 CONTROL • 10 ELECTRONIC WARFARE • 12 VOICE GROUP A • 13 VOICE GROUP B • 19 NON-C2 TO NON-C2 • 20 NON-C2 TO NON-C2 • 21 BMD • 22 COMPOSITE A • 23 COMPOSITE B • 27 JOINT NET PPLI • 29 RESIDUAL • 30 IJMS POSITION & STATUS • 31 OTHER IJMS DATA NPG’s
RELAY UHF LOS Only Paired Slot relay
Originator Tx in T/S (X) Paired Slots Paired Slots C2 C0 A0 A3 B0 B1 B3 C3 B4 C4 A1 A2 A4 A5 C1 B2 X X Y Re-Tx for second Hop by additional relay platform The relay platform will re-Tx in the timeslot controlled by the relay delay (6-31). Y is the re-Tx slot, with a relay delay of 6 timeslots RELAY The relay terminal Rx in (X)
RELAY Fixed Format and free text Capable of relaying to different nets No limit to relay hops
UK PLATFORMS • In Service • E3D Tornado F3 • Nimrod (R) VC10 & Tristar • JAPNMS (NMGB) C130 • JPC TJF • RN (CVS & T42) RN (JPC) • GRAP (RA & 16 AAB) • Future • EFA Typhoon ASTOR • MRA (4) T45 • GBAD
OTHER NATIONS USA (USAF, USN, USMC, US Army) France Germany Italy Netherlands Norway Belgium Denmark Spain Canada Australia Switzerland Japan and others