Comm 32 Introduction to datalink

Question 1

What is Data Link?

Answer 1

Any channel or communication path connecting data processing equipment (terminals) used for the transfer or exchange of information in the form of a standard message format and according to a particular protocol.

Question 2

• Primary purpose of data link is

Answer 2

sharing of information for :

- Intelligence, Surveillance and Reconnaissance (ISR)
- Command & Control
- Targeting

Question 3

Components of a generic system data link

Answer 3

• Terminal Equipment
  
  • Computers
    - Sensors
    - Display and Control
  • Modem/Radios
• Communication Networks
• Links connect platform computers using comms equipment

Question 4

Protocols of communication network

Answer 4

• Set of unique rules specifying sequences of action necessary to perform communication functions.
• Examples
  - Roll Call (Link11)
  - TDMA Time Division Multiple Access(Link16)
  - Dynamic TDMA Network (Link22)
  - CDMA (Code Division Multiple Access) Internet Protocol

Question 5

Net Coverage

Answer 5

• Line of Sight (LOS)
  - Networks over UHF and other LOS bands
  
  • Beyond LOS (BLOS)
    - Networks over SATCOM(L,C,X,Ku,Ka Bands)
    - HF
    - Ad-hoc Relay

Question 6

Types of Communications Networks

Answer 6

• Simplex – Communications in one direction only
• Half Duplex – Communications in both directions, but not both ways simultaneously
• Full Duplex – Communications in both directions simultaneously

Question 7

Characteristics of Current Data Link Types
11
16
TCDL

Answer 7

• Link 11 (TADIL A)
  - NATO Standard Maritime Data Link
• Link 16 (TADIL J)
  
  • NATO Standard Air Control Data Link
  • Evolved to become a multi elemental Data Link
• Tactical Common Data Link (TCDL)
  
  • Sensor dedicated data sharing

Question 8

Link 11 (TADIL A)
Concept:

Capabilities:

Limitations:

Answer 8

Concept:

• Computer to computer (TDS) mutual exchange of information among net participants.
• Used in the Maritime environment since the 1960s.

Capabilities:

• HF for BLOS transmissions
• UHF for LOS transmissions
• Half duplex (Link11A) or full duplex (Link11B) data exchange
• Secure (encrypted)
• NATO Standard message format

Limitations:

• One Net Control Station (NSC) is a single point of failure
• Limited number of participants (Picket Units PU) per net
• Limited information available
• Small bandwidth
• Low data rate

Question 9

Link 16 (TADIL J)
Concept:

Capabilities:

Limitations:

Answer 9

Concept:

• Communication, navigation, and identification system that supports information exchange between tactical command, control, communications, computers, and intelligence (C4I) systems.
• Used in the air control environment since the 1990s.

Capabilities:

• L- Band communications
• “Nodeless” communication structure (No NCS)
• High capacity Data Link (more participants)
• Secure (encrypted)
• NATO Standard message format (J series)

Limitations:

• LOS Only
• Interference with IFF and navaid systems
• Limited use for targeting

Question 10

Tactical Common Data Link (TCDL)
Concept:

Capabilities:

Limitations:

Answer 10

Concept:

• Version of Common Data Link designed to provide near real-time linkage between tactical sensors, C2 decision-makers and force enablers
• Widely used in ISR and targeting operations
• Mostly dedicated to Full Motion Video but expanded to other sensors.

Capabilities:

• Wide band modem communications (C,X,Ku,Ka bands)
• Open and scalable net structure
• BLOS over SATCOM
• Full duplex comms between surface terminals and airborne terminal (directional)
• Simplex communications for Rover feed 9omni-directional)

Limitations:

• Rover feed is unencrypted and ground footprint is less than LOS
• Restriction in LOS directional mode due to interference
• Communication in BLOS is very expensive for the high data rate required

Question 11

Data link application to Intelligence, Surveillance & Reconnaissance

Answer 11

Encompasses multiple activities related to the planning and operation of systems that collect, process and disseminate data in support of current and future military operations.

Question 12

Command, Control, Computer, Communication, Intelligence, Surveillance and Reconnaissance (C4ISR)

Answer 12

• Consists of the doctrine and concepts, the connectivity, the information systems, the sensors, and the tools required to effectively support command across the entire spectrum of military operations through the timely attainment of trusted and relevant information.

Question 13

C2 Data Link (Link11 and Link16)

Answer 13

• Share and exchange info amongst C2 and other players in the battlespace
• Indirectly using other units’ sensors via C2 Data Lnk net to compile a picture
• Other tactical messaging
• Targeting (relies on voice comms)