HLA is a framework for distributed simulation systems
developed by the U.S. Defense Modeling and Simulation Office (DMSO). HLA attempts
to provide a very generic environment that any virtual object can attach to
in order to participate in a simulation. It is a very well-thought architecture
that defines standard services and interfaces to be used by all participants
in order to support efficient information exchange. HLA is adopted as the facility
for Distributed Simulation Systems 1.0 by the Object Management Group (OMG)
and is now in the process of becoming an open standard through the IEEE.
HLA's Runtime Infrastructure (RTI) is a set of software components that implement
the services specifies by HLA. Today, a few RTI implementations for different
platforms are available.
If you want to learn HLA... http://www.ecst.csuchico.edu/~hla/courses.html
DIS / HLA - military standards tailored to the requirements of simulation and
war games. DIS is an
efficient, if inflexible, protocol for medium scale simulation. The imaginatively
named Higher Level
Architecture (HLA) is the spiritual successor to DIS, although it focuses more
closely on the
problems of arranging very large-scale simulations rather than the run-time
distribution of data.
HLA remains a hot topic in defence circles. Limitations of the specification
provide great
opportunities for the lab, with the prospect of serious defence dollars on offer
for a full simulation
infrastructure
Adam Martin wrote:
> From: "Lee Sheldon" <linearno@gte.net>
>> Ann Arbor, MI - October 2, 2001 - Cybernet Systems, an Ann
>> Arbor-based research and development firm, today announced the
>> availability of a new massive multi-player networking
>> architecture that enables developers to create online games in
>> which tens of thousands of players can simultaneously interact
>> in the same environment.
>> www.openskies.net/news/networkrelease.shtml
>> Anybody have any thoughts about this?
> Having read all their stuff, and looked at the technology, I'd say
> its not as interesting as they make it sound; my impression from
> what they are saying publicly is that they are merely rehashing
> some pretty old ideas from wide area network multimedia stream
> distribution, wrapping it up as "applicable to MMOGs" and trying
> to patent it. Will check out the patent when we can (they are
> potential competition to our work) but based on their "white
> paper" I'm rather disappointed by the disparity between the
> marketing hype and the reality.
They're one of a couple players in the field currently. Each of the
current products is taking a somewhat different approach, both in
technological details and the business model behind the company.
The above summary of Open Skies leaves out much of their history and
grounding in solid research and implementations. Open Skies bases
their product on HLA, the Department of Defense standard "High Level
Architecture" which was the successor to the older DIS
standards. Cybernet has been working in that field for years, so I'd
doubt that that part of their product is new or totally unproven.
(That's not something that I'd expect to be true for some of the
other products in the field.)
A good starting point for information on HLA itself is at
http://www.dmso.mil/hla
The High Level Architecture (HLA) is a general purpose
architecture for simulation reuse and interoperability. The
HLA was developed under the leadership of the Defense Modeling
and Simulation Office (DMSO) to support reuse and
interoperability across the large numbers of different types of
simulations developed and maintained by the DoD. The HLA
Baseline Definition was completed on August 21, 1996.
Now, as Adam described, in addition to that, they're also pitching
their distributed caching/etc system.
In their favor, they also have a lot more public documentation than
some, possibly all, of their competitors. Also, if more people were
to be following the HLA standards, it might be interesting to see to
what extent interoperability among the products (at the source level
if nothing else) might be possible or useful.
They don't appear to have a lot of direct game systems or anything
at that level pre-built and part of their package. They seem to
currently be focusing their product offerings at the lower levels,
with promises of more to come later and sample code that does some
of the game system type things. So it isn't something that
currently appears to be aiming at the same type of market as the
MMORPG Construction Kit. :)
Their licensing isn't very clear to me (without contacting them).
Some of their distributed caching/server technology appears at least
superficially to be similar to TerraPlay:
http://www.terraplay.com/.
Overall, I think there's a good bit of interesting fodder for
MUD-Dev discussion in their technology, if there's interest in that
sort of thing on the list. (I don't think HLA has ever really been
discussed on list? Or really any of the practical models for
scaling that are currently seeing commercial application.)
- Bruce