Distributed Interactive Simulation (DIS) is an IEEE standard for conducting real-time

Real-time Simulation

Real-time Simulation refers to a computer model of a physical system that can execute at the same rate as actual "wall clock" time. In other words, the computer model runs at the same rate as the actual physical system...

 platform-level wargaming

Wargaming

A wargame is a strategy game that deals with military operations of various types, real or fictional. Wargaming is the hobby dedicated to the play of such games, which can also be called conflict simulations, or consims for short. When used professionally to study warfare, it is generally known as...

 across multiple host computers and is used worldwide, especially by military

Military

A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...

 organizations but also by other agencies such as those involved in space exploration

Space exploration

Space exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....

 and medicine

Medicine

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

.

History

The standard was developed over a series of "DIS Workshops" at the Interactive Networked Simulation for Training symposium, held by the University of Central Florida's

University of Central Florida

The University of Central Florida, commonly referred to as UCF, is a metropolitan public research university located in Orlando, Florida, United States...

 Institute for Simulation and Training

Institute for Simulation and Training

The Institute for Simulation and Training is a research institute of the University of Central Florida located in Orlando, Florida, USA. The director of the school is Randall Shumaker....

 (IST). The standard itself is very closely patterned after the original SIMNET

SIMNET

SIMNET was a wide area network with vehicle simulators and displays for real-time distributed combat simulation: tanks, helicopters and airplanes in a virtual battlefield. SIMNET was developed for and used by the United States military...

 distributed interactive simulation protocol, developed by Bolt, Beranek and Newman (BBN) for Defense Advanced Research Project Agency (DARPA) in the early through late 1980s. BBN introduced the concept of dead reckoning

Dead reckoning

In navigation, dead reckoning is the process of calculating one's current position by using a previously determined position, or fix, and advancing that position based upon known or estimated speeds over elapsed time, and course...

 to efficiently transmit the state of battle field entities.

In the early 1990s, IST was contracted by the United States Defense Advanced Research Project Agency to undertake research in support of the US Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 Simulator Network (SimNet) program. Funding and research interest for DIS standards development decreased following the proposal and promulgation of its successor, the High Level Architecture (simulation) in 1996. HLA was produced by the merger of the DIS protocol with the Aggregate Level Simulation Protocol

Aggregate Level Simulation Protocol

The Aggregate Level Simulation Protocol is a protocol and supporting software that enables simulations to interoperate with one another. Replaced by the High Level Architecture , it was used by the US military to link analytic and training simulations.ALSP consists of:#ALSP Infrastructure...

 (ALSP) designed by MITRE

MITRE

The Mitre Corporation is a not-for-profit organization based in Bedford, Massachusetts and McLean, Virginia...

.

There was a NATO standardisation agreement (STANAG

STANAG

STANAG is the NATO abbreviation for Standardization Agreement, which sets up processes, procedures, terms, and conditions for common military or technical procedures or equipment between the member countries of the alliance. Each NATO state ratifies a STANAG and implements it within their own...

 4482, Standardised Information Technology Protocols for Distributed Interactive Simulation (DIS), adopted in 1995) on DIS for modelling and simulation interoperability. This was retired in favour of HLA in 1998 and officially cancelled in 2010 by the NATO Standardisation Agency (NSA).

The DIS family of standards

DIS is defined under IEEE Standard 1278:

• IEEE 1278-1993 - Standard for Distributed Interactive Simulation - Application protocols
• IEEE 1278.1-1995 - Standard for Distributed Interactive Simulation - Application protocols
• IEEE 1278.1-1995 - Standard for Distributed Interactive Simulation - Application protocols
• IEEE 1278.1A-1998 - Standard for Distributed Interactive Simulation - Application protocols Errata (May 1998)
• IEEE-1278.2-1995 - Standard for Distributed Interactive Simulation - Communication Services and Profiles
• IEEE 1278.3-1996 - Recommended Practice for Distributed Interactive Simulation - Exercise Management and Feedback
• IEEE 1278.4-1997 - Recommended Practice for Distributed Interactive - Verification Validation & Accreditation
• IEEE 1278.5-XXXX - Fidelity Description Requirements (never published)

In addition to the IEEE standards, the Simulation Interoperability Standards Organization

Simulation Interoperability Standards Organization

The Simulation Interoperability Standards Organization is an organization dedicated to the promotion of modeling and simulation interoperability and reuse for the benefit of diverse M&S communities, including developers, procurers, and users, world-wide.-History:The Simulation Interoperability...

 (SISO) maintains and publishes an "enumerations and bit encoded fields" document yearly. This document is referenced by the IEEE standards and used by DIS, TENA and HLA federations. Both PDF and XML versions are available.

Current status

SISO, a sponsor committee of the IEEE, promulgates improvements in DIS. Major changes are already in the DIS 7 draft update to IEEE 1278.1 to make DIS more extensible, efficient and to support the simulation of more real world capabilities.

Application protocol

Simulation state information is encoded in formatted messages, known as protocol data unit

Protocol data unit

In telecommunications, the term protocol data unit has the following meanings:#Information that is delivered as a unit among peer entities of a network and that may contain control information, address information, or data....

s (PDUs) and exchanged between hosts using existing transport layer

Transport layer

In computer networking, the transport layer or layer 4 provides end-to-end communication services for applications within a layered architecture of network components and protocols...

 protocols, including multicast, though broadcast User Datagram Protocol

User Datagram Protocol

The User Datagram Protocol is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol network without requiring...

 is also supported. There are several versions of the DIS application protocol, not only including the formal standards, but also drafts submitted during the standards balloting process.

• Version 1 - Standard for Distributed Interactive Simulation - Application Protocols, Version 1.0 Draft (1992)
• Version 2 - IEEE 1278-1993
• Version 3 - Standard for Distributed Interactive Simulation - Application Protocols, Version 2.0 Third Draft (May 1993)
• Version 4 - Standard for Distributed Interactive Simulation - Application Protocols, Version 2.0 Fourth Draft (March 1994)
• Version 5 - IEEE 1278.1-1995
• Version 6 - IEEE 1278.1a-1998 (amendment to IEEE 1278.1-1995)
• Version 7 - IEEE P1278.1 (in development - completion anticipated 2011-2012. See External Link - DIS Product Development Group.) Version 7 is also called DIS 7. This is a major upgrade to DIS to enhance extensibility and flexibility. It provides extensive clarification and more details of requirements, and adds some higher-fidelity mission capabilities.

Protocol data units

The current version (DIS 6) defines 67 different PDU types, arranged into 12 families. Frequently used PDU types are listed below for each family. PDU and family names shown in italics are included in present draft DIS 7.

• Entity information/interaction family - Entity State, Collision, Collision-Elastic, Entity State Update, Attribute
• Warfare family - Fire, Detonation, Directed Energy Fire, Entity Damage Status
• Logistics family - Service Request, Resupply Offer, Resupply Received, Resupply Cancel, Repair Complete, Repair Response
• Simulation management family - Start/Resume, Stop/Freeze, Acknowledge
• Distributed emission regeneration family - Designator, Electromagnetic Emission, IFF
  Identification friend or foe
  In telecommunications, identification, friend or foe is an identification system designed for command and control. It is a system that enables military and national interrogation systems to identify aircraft, vehicles, or forces as friendly and to determine their bearing and range from the...
  
  /ATC
  Air traffic control
  Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...
  
  /NAVAIDS
  Navigational aid
  A navigational aid is any sort of marker which aids the traveler in navigation; the term is most commonly used to refer to nautical or aviation travel...
  
  , Underwater Acoustic
  Underwater acoustics
  Underwater acoustics is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water and its boundaries. The water may be in the ocean, a lake or a tank. Typical frequencies associated with underwater acoustics are between 10 Hz and...
  
  , Supplemental Emission/Entity State (SEES)
• Radio communications family - Transmitter, Signal, Receiver, Intercom Signal, Intercom Control
• Entity management family
• Minefield family
• Synthetic environment family
• Simulation management with reliability family
• Live entity family
• Non-real time family
• Information Operations family - Information Operations Action, Information Operations Report

External links

• SISO DIS Product Support Group