Distributed Interactive Simulation

Distributed Interactive Simulation ( DIS ) denotes a defined in the IEEE 1278 data exchange standard for the control of simulation systems.

Basics

DIS is used in professional civil and military simulations to optimize the training (eg in traffic control centers, radar centers). Using DIS networked simulation systems can be simulated real-time position information, eg for synchronous control of radar simulators, exchange and so enable users of its networked systems in the position to perform an identical environment representation in their respective simulator.

A DIS simulation object is referred to as " Entity ". Each entity must have a unique (unique ) identifier wear (Entity ID).

Data exchange

The communication takes place via DIS packet - oriented with UDP packets ( multicast or broadcast ) and TCP. The actual data are binary coded. The byte order is in "network order".

The connected via a Wide Area Network (WAN) or Local Area Network (LAN) simulation participants may include the following information blocks ( Protocol Data Unit, PDU) exchange:

  • Entity State - indicates the position, course and speed as well as the sensor signature of a simulation target ( eg strength of the radar echoes), also type properties of the underlying simulation model,
  • Collision - enables the evaluation of whether two simulated objects ( eg ships or aircraft) crashed.
  • Firing - a special military version of the Entity State PDU for the simulation of missiles and rockets.
  • Environment - Data for simulation of environmental background, such as land echoes, clouds and rain (clutter ).

The currently valid IEEE 1278 -1a standard 1998 contains 76 different PDUs ranging, inter alia, to the simulation of minefields.

A PDU header always contains the following components:

  • Time Stamp ( time)
  • PDU type
  • Version

Benefits

  • Simple construction of a simulation
  • No management capabilities
  • Very quickly
  • PDUs easily interpretable with Network Monitor as Wireshark
  • Low LAN - network load by broadcast.

Disadvantages

  • When implementing a DIS simulation much networking code itself must be programmed
  • Any routing problems between subnets ( as broadcast ), which can be compensated for by a so-called forwarders but

Successor

Using a similar approach, but object-oriented, takes the High Level Architecture ( HLA), in which many experts see the improved successor of the DIS standard. HLA support -related communication via a central administration.

  • Computer Networks
High-level architecture (simulation)
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