RD

1
RDE Forum

• 04F-SIW-018
• Open Run-Time Infrastructure Protocol
• Study Group Final Report
• John M. Woodyard
• AFRL/IFSC
• john.woodyard_at_wpafb.af.mil
• Kevin Mullally
• General Dynamics C4 Systems
• kevin.mullally_at_gdds.com

2
Introduction

• Open RTI Protocol Study Group (ORTI SG) sponsored
  by RDE forum as a result of paper 03S-SIW-112
• The goal of the Study Group was to look into the
  usefulness of a creating a standard to describe
  message formats and data handling algorithms for
  RTI services which would be encapsulated in an
  open message-based protocol. (Over-The-Wire RTI
  Standard)

3
Defining the TOR

• Started with assumption from 99F-SIW-001 - RTI
  Interoperability Study Group Final Report
• We must develop a means by which different RTIs
  can talk to each other we need to be able to
  have heterogeneous RTIs. Heterogeneous
  interoperability is good its good from a
  cost-effective standpoint, it's good from a
  competition standpoint, it's good from the
  standpoint of community growth.
• First meeting of the SG concluded that this
  statement shouldnt be taken as an axiom.

4
Focus Questions from TOR

• What are the problems caused by proprietary RTI
  communication protocols?
• What is the possible utility of an Open RTI
  Protocol in addressing these problems?
• Is the simulation community interested in
  supporting the Open RTI Protocol?
• How can the Open RTI Protocol be used to support
  HLA RTI Research and Development?
• How does the Open RTI Protocol impact simulation
  interoperability?
• Should the Open RTI Protocol investigation evolve
  into a SISO balloted product?

5
What are the problems caused by proprietary RTI
communication protocols?

• Need to obtain one RTI per federation for an
  exercise.
• Currently you can have only one RTI per
  federation without employing some sort of a
  bridge.
• One advantage of a wire standard is when people
  come together you only need to have bought or
  developed one RTI per federate not one for each
  federation you participate in.
• One reason to have a wire standard is the ability
  to look inside the black box. A wire standard
  allows the user to troubleshoot by being able to
  decode what is on the wire.
• Academia would like to be able communicate
  between different RTIs and RTI versions in
  different labs.

6
What is the possible utility of an Open
RTIProtocol in addressing these problems?

• Consensus of the SG that a small group that would
  actually use a wire standard RTI. To take it to a
  larger group it would require an investment by
  vendors and or a large sponsor like the DoD.
• A wire standard would allow the creation of a
  one-off API which addresses the special needs of
  an embedded system.
• The group came up with three levels in which a
  wire standard could be supported. As the levels
  increase the degree of difficulty goes up for
  making a common standard and implementing the
  changes required for the standard.
• Level 1 includes update, reflect, send
  interaction, and receive interaction.
• Level 2 includes register, discover, delete, and
  remove.
• Level 3 includes publish, and subscribe
• General Dynamics released a draft protocol with
  these levels of RTI functionality

7
Is the simulation community interested
insupporting the Open RTI Protocol?

• It appears, based upon the support of the Open
  RTI Protocol SG at the SIWs and on the reflector
  activity, that there are not enough interested
  people to support the development of an Open RTI
  Protocol (wire standard).
• It is the case of finding someone that has the
  time to actively lead the study group and get a
  small cadre of dedicated people (3-5) to come up
  with specific, detailed alternatives and beat the
  bushes to get all the major stakeholders involved
  in the review process.
• This group has not surfaced.

8
How can the Open RTI Protocol be used to support
HLA RTI Research and Development?

• Dictating a wire standard dictates the
  distributed algorithm so from the point of view
  of RTI research a wire standard actually may
  inhibit research.
• On the other hand, a wire standard is desired by
  people from academia to support research using a
  RTI.

9
How does the Open RTI Protocol impactsimulation
interoperability?

• SG determined that this question was answered in
  context of other questions.

10
Should the Open RTI Protocol investigation evolve
into a SISO balloted product?

• Based upon the support at the SIWs and the lack
  of activity on the reflector, there doesnt
  appear to be enough support at this time to go
  ahead with a balloted product for a wire
  standard.
• This doesnt mean that there is not any interest
  in this sort of a product, rather it means that
  the resources are not available to do the work at
  this time.

11
Conclusions

• Users have confirmed their desire for
  Over-The-Wire type RTI interoperability
• RTI developers have highlighted functionality
  where this could be possible
• The simulation community has an opportunity to
  pursue an Open RTI Protocol