=Paper=
{{Paper
|id=Vol-555/paper-6
|storemode=property
|title=Referent Tracking for Command and Control Messaging Systems
|pdfUrl=https://ceur-ws.org/Vol-555/paper6.pdf
|volume=Vol-555
}}
==Referent Tracking for Command and Control Messaging Systems==
https://ceur-ws.org/Vol-555/paper6.pdf
Referent Tracking for Command and Control Messaging Systems
Shahid Manzoor, Werner Ceusters and Barry Smith
Center of Excellence in Bioinformatics & Life Sciences, University at Buffalo
701 Ellicott Street, Buffalo NY, 14214
smanzoor@buffalo.edu, ceusters@buffalo.edu, phismith@buffalo.edu.
Abstract – The Joint Battle Management Language (JBML) uncertain, conflicting and erroneous, either because of
is an XML-based language designed to allow Command and misinterpretations committed by friendly agents or
Control (C2) systems to interface easily with Modeling and falsifications introduced through counter-intelligence
Simulation (M&S) systems. While some of the XML-tags defined activities, this distinction is crucial.
in this language correspond to types of entities that exist in
reality, others are mere syntactic artifacts used to structure the In this paper we show how a realism-based ontology,
messages themselves. Because these two kinds of tags are not combined with a rule language, can be used to make these
formally distinguishable, JBML messages in effect confuse data distinctions explicit and to store the contents of JBML
with what the data represent. In this paper we show how a messages in a Referent Tracking System (RTS) in a format
realism-based ontology combined with a rule language can be
that mimics the structure of reality.
used to make these distinctions explicit. The approach allows
storage of the contents of JBML messages in a Referent In [2] we demonstrated how an RTS, i.e. a system that
Tracking System in a format that mimics the structure of reality forces assertions to be expressed by means of statements that
thereby providing an aid to message validation. use globally unique and singular identifiers for each referent
Index Terms - Realism-Based Ontology, Command and mentioned [3] and that are structured according to the
Control, Referent Tracking, JBML principles outlined in Basic Formal Ontology [4], may help
the Intelligence Community to share information
unambiguously. Here, we report on further enhancements of
I. INTRODUCTION
our prior work to integrate XML-based information systems
The Joint Battle Management Language (JBML) was with RTS, using JBML as a specific example. We describe a
designed in response to the growing need to interface prototype application that uses a realism-based ontology to
Modeling and Simulation (M&S) systems with Command, parse JBML messages and that provides reasoning facilities
Control, Communications, Computers, Intelligence, for the validation of the data. The application works by (1)
Surveillance, and Reconnaissance (C4ISR) systems in order generating identifiers for all the real-world entities and their
to provide the user with capabilities that support operational relationships that are mentioned in given messages, and (2)
functions including Course of Action (COA) Development storing these identifiers in an RTS.
and Analysis, mission rehearsal, and execution monitoring
[1]. Its main benefit is that it overcomes the interoperability
problem caused by the use of unstructured “free text” within II. ONTOLOGY-BASED PROCESSING OF MILITARY MESSAGES
the operational C2 messages that are passed within C4ISR An RTS is an ontology-based database which uses globally
systems, specifically for the most critical C2 information: the unique identifiers (called IUIs) to represent: (1) instances
commander’s intent, orders and directives. While suitable for (spatiotemporal particulars, including people, commands,
interpersonal communication, free text is inadequate for use places, events), (2) the relations that hold between such
by simulations and robotic or software-based components. instances, (3) the (potentially multiple) names that are
assigned to such instances, and (4) the universals or classes
JBML is highly structured and the majority of its XML-
that such instances instantiate [2, 3, 4]. The RTS thereby
tags (or ‘elements’) are given very intuitive labels. Yet, the
provides a framework for the logically coherent formulation
language generally suffers from the problem that while some
of assertions made about any of the given entities, including
of the tags denote generic entities in reality that are
those types of assertions contained in C2 messaging.
instantiated by the referents denoted by the elements’ contents
in a specific message, other tags provide information about An example of a military message in JBML is shown in
the message structure itself, rather than what the message is Listing 1. The message represents a mission that is assigned
about. Because these two kinds of tags are not formally to an army unit with identifier ‘2TF A TEAM’. The army unit
distinguishable, JBML messages confuse data with what these has to move between points whose coordinates are given
data represent. This does not need to be a problem if the data under the WhereValue element in the XML. In the prototype
are always an accurate representation of reality. But in an implementation here described, assertions about entities are
intelligence context, where large amounts of data are inserted in the RTS as triples, for example:
IUI-1004 instanceof MilitaryMission and thus no messages have as yet been processed, the RTS
IUI-1005 instanceof MilitaryUnit database contains no information. As more and more
IUI-1004 missionAssignedTo IUI-1005 messages are processed, the RTS becomes populated with
IUI-1005 currentPostionAt IUI-1014 successively more IUIs and with corresponding statements
about the relationships between the referents of these IUIs.
The first triple represents a statement to the effect that the
Knowledge obtained through parsing earlier messages is used
entity IUI-1004 instantiates the universal MilitaryMission; the
to improve parsing of new messages, to check the consistency
second triple a statement to the effect that the entity IUI-1005
of the information provided in new messages, and so forth.
instantiates the universal MilitaryUnit; the third triple
represents a statement to the effect that the mission with The whole process is carried out in four steps.
identifier IUI-1004 is assigned to the military unit with
identifier IUI-1005. The fourth triple represents a statement to A. Step 1: Structural Analysis of XML
the effect that the current position of IUI-1005 is location In the first step, a military message is parsed with the goal
IUI-1014. of detecting entities referred to and the relations between
We have developed a prototype ontology for command and them, as shown in Fig. 2. The nodes of the graph correspond
control systems called ‘C2-Test-Ontology’, which uses a to putative entities within the domain of the message, while
subset of UCore SL, an ontology designed to support the the edges correspond to relations. Nodes without a prefix are
Universal Core data schema [5], to link the JBML tags from entities named explicitly in the message. Nodes with the “rts:”
the military messages to UCore SL. The ontology tells us prefix are generated on the basis of the XML-structure of the
what data elements in a military message refer to what kinds message. Some of them will correspond to real entities, but
of real world entities (e.g. ArmyUnit, MilitaryMission) and others are inserted as a side-effect of the oddities of the XML
what relationships obtain between them. syntax. It is one of the tasks of our application to turn the
resultant distorted view of reality into a realistic picture which
We have also developed a Middleware program which conforms to good ontological principles [6].
parses military messages, and – drawing on knowledge
contained in the C2-Test-Ontology – communicates with the In the first step, the middleware does not use any
RTS and a rule-based reasoner to assign IUIs to the entities knowledge from the UCore SL or C2-Test ontologies. Rather
mentioned in the messages. The architecture of our system is it iterates over the XML structure of the message using a
shown in Fig. 1. When the middleware runs for the first time, depth first iteration strategy, in which each XML element is
viewed as a relation between possible entities. The iteration
leads to the creation of a new graph in which the software
creates nodes automatically without contacting the RTS. As
2TF A TEAM an example, the XML element ‘’ is not explicitly
labeled in the message above. It is immediately followed by
MOVE , which is also not explicitly labeled. What is
the relation between these two elements? The message
provides no answer to this question. Our application in this
first step assigns IUI identifiers to Task and GroundTask. By
using ontologies in later steps, it will become possible to
48.9100583
arrive at more determinate representations.
39.9570562
0.0
Command & Control System
48.9056792 Sends JBML XML Message
Ontology
39.9891024
0.0
Rules Middleware
Communicate With RTS To Assign IUI
Reasoner Referred in XML Message
RTS
Fig. 1: Command & Control Application Integration with RTS
Listing 1: An Example of a JBML Message
rts:1004 jbml:StartWhen rts:1015
rts:1015 jbml:WhenTime rts:1016
rts:1016 jbml:StartTimeQualifier “NLT”
rts:1016 jbml:DateTime “110800ZAUG2025”
Listing 2: Triples representation generated while analyzing the message in
Listing 1
example ‘rts:1015’ and ‘rts:1016’ denote the same time, and
‘rts:1011’ and ‘rts:1012’ denote the same particular location.
In line with the Referent Tracking principles, such duplicate
identifiers must be removed. Inspection reveals that some
triples, such as
rts:1001 jbml:OrderPush rts:1002
rts:1002 Task rts:1003
rts:1003 jbml:GroundTask rts:1004
are defective from an ontological point of view and these too
must be removed. A task, for example, is clearly not a
relationship. This restructuring cannot however be achieved
computationally in this step, because the XML framework
does not provide explicit information sufficient to ensure the
ontological soundness of the representation. We have
therefore built another service, executed in step 2 below,
which translates information implicit in the XML structure of
a message into explicit assertions.
Fig. 2: Graph generated in the first step of the middleware
B. Step 2: Shallow translation of XML
To achieve ontologically correct information of this sort we
The entities and their relations shown in the graph in Fig. 2 use a variant of the Jena rule-based reasoning language [7] to
are represented in the middleware by means of triples. The formulate rules stating the conditions for adding or removing
first triple in the graph is: assertions in the graph.
rts:1001 jbml:OrderPush rts:1002 We employ for this purpose forward-chaining reasoning
The first and last terms of this triple denote entities, while the rules, each consisting of (1) a body and (2) a head. The
middle term denotes the relationship between these entities. former specifies the set of patterns which triples in the
message graph must match if they are to be capable of being
As a further example, the triples representation for the node transformed into triples that are ontologically well-formed.
rts:1004 and its relations with rts:1015 and its descendents are The latter consists of a set of ontologically well-formed
shown in Listing 2. triples into which the triples in the set specified in (1) to be
This graph does not yet provide a representation which is translated.
faithful to reality in terms of the logical and ontological We distinguish four different types of rules:
principles on which UCore SL and our C2-Test-Ontology are
based. Clearly, some nodes in the figure denote genuine • If a rule name is prefixed with ‘ded_’ (for
entities, including: deduction), then it is a deduction rule as described
above.
rts:1004, a particular military ground mission
• If a rule name is prefixed with ‘red_’ (for reduction),
rts:1005, a particular military unit,
then the rule removes the triples matched against the
rts:1015, a particular time
pattern in part (1) of the rule and adds the triple set
rts:1012, a particular location.
in part (2).
Moreover some nodes are such that they are unique instance • If a rule name is prefixed with ‘map_’ (for mapping)
identifiers, as is required by Referent Tracking principles. then it assigns appropriate IUIs to entities that are
However, the graph also contains many violations of these mentioned repeatedly in the message.
principles. Some nodes denote in a non-unique way; for
• If a rule name is prefixed with ‘val_’ (for Since the rule is of type ‘reduction’, the four triples are
validation), then its goal is to check for removed from the military message triple set, and the
inconsistencies in the data and to provide following three triples are inserted instead:
corresponding notification to the receiver of the
rts:1004 c2:StartWhen rts:1015
message.
rts:1015 ro:instanceof c2:TimeEvent
Our middleware provides distinct services for each of the rts:1015 c2:NoLaterThan “110800ZAUG2025”
rule types described above.
The first represents the assertion that the mission with
An example of a deduction rule is: identifier #1004 starts at time event #1015. The second
represents the assertion that entity #1015 instantiates the
[ded_1 (?x jbml:Task ?y) (?y jbml:GroundTask ?z)
TimeEvent universal from the C2-Test-Ontology, and the
-> (?z ro:instanceof c2:MilitaryMission)]
third represents the assertion that the time event #1015 occurs
which asserts that if (i) for two putative entities the ‘Task’ at a time point which is not later than the time specified by the
relationship holds and if (ii) the target-entity of this relation “110800ZAUG2025” date-time stamp. The execution of rule
stands in a ‘GroundTask’ relation with a third entity, then (iii) red_7 shows (1) how redundant entities and their relations can
the first two entities are erroneous artifacts generated in step be removed from military messages in such a way that (2) an
1, while the third entity is a MilitaryMission in the terms of ontology can be used to infer automatically assertions about
our C2-Test-Ontology. Note that the issue here is not whether the entities in the real world which are referred to in these
this specific rule is correct. What we are offering here are messages.
examples. Crafting the needed set of rules for JBML and
Note that in this second step, the middleware executes only
other XML-based languages is a task which needs to be
rules of types 1) and 2). Execution of deduction and reduction
performed when once the general strategy has been
rules over the triple set whose visualization is shown in Fig. 2
formulated and tested.
then yields a new triple set whose visualization is shown in
Here ‘ded_1’ is the name of the rule. Variables are prefixed Fig. 3. This new triple set conforms to sound logical and
by ‘?’ and serve as placeholders for the actual terms in the ontological principles; specifically: there is here no
matched triples in their respective places. The following are redundancy, and all nodes and edges in the graph are
triples that match the conditions of the rule above: ontologically well-formed.
(rts:1002 jbml:Task rts:1003) (rts:2003 jbml:GroundTask rts:1004), Each node of the graph whose label is prefixed with ‘rts:’
where variables in the rule bind terms in the matched triples contains the IUI of an entity referred to in the message, as
as follows: ?x = rts:1002, ?y = rts:1003, ?z = rts:1004. follows:
Under the head part of the rule, the software inserts the - #1004 denotes a particular military mission
triple ‘rts:1004 ro:instanceof c2:MilitaryMission’, where the - #1015 denotes the particular TimeEvent when
term ‘ro:instanceof’ denotes the instanceof relation from the mission #1004 must start
Relation Ontology (‘ro’) [8], and the term - #1005 denotes the military unit that must perform
‘c2:MilitaryMission’ denotes the MilitaryMission universal mission #1004
taken from the C2-Test-Ontology (‘c2’). - #1009 denotes the line along which the #1005 unit
has to move
An example of a reduction rule is: - #1014 and #1012 denote distinct points
[red_7: (?x jbml:StartWhen ?y) corresponding to the start and end of the #1009 line.
(?y jbml:WhenTime ?z)
(?z jbml:StartTimeQualifier "NLT") C. Step 3: Entity Tracking and Semantic Verification
(?z jbml:DateTime ?l) In the third step, rules prefixed with ‘map_’ are executed
-> (?x c2:StartWhen ?y) over the triple set that results from step 2. The middleware
(?x ro:instanceof c2:TimeEvent) first checks whether the RTS is empty. If it is, there cannot be
(?x c2:NoLaterThan ?l)] any duplicate entries and the triple set is simply inserted into
The body of this rule is matched by the following set of the RTS and processing stops. However, if the RTS is not
triples, generated from the message shown in Listing 2 . empty, then the middleware program continues to execute this
step to. Suppose the middleware receives a second military
rts:1004 jbml:StartWhen rts:1015 message (shown in Fig. 4) and that the RTS database contains
rts:1015 jbml:WhenTime rts:1016 the triples shown in Fig. 3. Here, the military unit named
rts:1016 jbml:StartTimeQualifier “NLT” ‘2TF A TEAM’ is assigned the IUI rts:2005. However, in the
rts:1016 jbml:DateTime “110800ZAUG2025” RTS used in the message analysis system there is already a
Fig. 3: Visualization of Ontologically Articulated Content of the XML message in Listing 1
Fig. 4: Second Military Message after Processing via Step 2
Fig. 5: Second Movement Mission as Described in the 2nd Example Message
military unit whose name is ‘2TF A TEAM’, to which the IUI This rule instructs the middleware to search for matching
rts:1005 has already been assigned. triples in the incoming message, in this case returning the
triple:
The Referent Tracking principles state that if the military
unit in the second message is the same as the one referred to rts:2005 jbml:UnitID “2TF A TEAM”
already in the RTS, then it should continue to be denoted by
the IUI rts:1005. It is this conformity to Referent Tracking As ‘?x’ refers to an entity (whose IUI is to be determined),
principles that is achieved by the mapping rules. the middleware replaces the IUI in the triple found by ?x. The
above triple is thus transformed into the following:
A mapping rule whose conditions are satisfied by the
incoming second message is: ?x jbml:UnitID “2TF A TEAM”
[map_1: (?x jbml:UnitID ?a) -> entity_found(?x)] The map_1 rule now instructs the middleware to search for
a corresponding triple in the RTS which returns, in this case:
rts:1005 jbml:UnitID “2TF A TEAM” strategies in relation to incoming messages on the basis of
information obtained through earlier messages. The benefit of
As a result, rts:2005 is replaced by rts:1005 in all
using middleware along with rules built on the basis of a well-
corresponding triples in the new message. The final output is
structured ontology such as our C2-Test-Ontology (itself an
shown in Fig. 5.
extension of UCore SL), is that, if changes occur, for example
At this stage, all triples of the incoming message are in in the format of the military messages or in our understanding
accordance with the RT principles, and the message triples of military reality, changes will need to be made only in the
are ready to be inserted into the RTS database in addition to rules and ontologies, and the need for further software
the triple (rts:1005 jbml:UnitID “2TF A TEAM”) which is changes will thus be reduced. Another benefit of this
already present. architecture is that the system can be re-used with other
information systems pertaining to other Communities of
At the end of these steps, an unambiguous representation of
Interest (CoI). The only changes we need to make are: (1)
the data – at least in terms of the C2-Test-Ontology – is
building an appropriate ontology for each new CoI, (2)
obtained, and additional reasoning over the data now becomes
writing a new parser to analyze the information coming from
possible.
the corresponding information system, and (3) defining
appropriate rules for that domain.
D. Step 4: Reasoning to Validate Incoming Messages
In this step, data validation rules are executed over the RTS We also did not use rules that provide alternative
database used by the middleware to check for any interpretations of inconsistent data. Note for instance that the
inconsistencies that may arise when inserting the content of inconsistency as concerns the location of the 2TF A TEAM
the new message into the RTS. discussed above might result from a false assumption about
which entity the name ‘2TF A TEAM’ in fact denotes – either
Imagine a scenario under which the RTS is in the state perhaps it denotes different units in different messages, or
shown in Fig. 3, and now the triples shown in Fig. 5, because in some messages typing errors have been made.
corresponding to a new planned mission for the 2TF A
TEAM, are ready to be inserted. The new mission involves The approach can be used not only to reason with messages
the movement of the team from location #2012. Because the in given formats, but also to integrate messages with different
new starting position is different from the current position of formats. Future work should be based on fully axiomatized
the unit as recorded in the database, it is not possible for the forms of the various ontologies. The C2-Test-Ontology
military unit to carry out the mission unless the starting point should also be dramatically extended to include not only
can be reached in due time. In this case, the middleware will JBML, but relevant content from JC3IEDM, and NIEM with
provide an alert warning of potential inconsistency of the the objective of creating fully automatized interoperability
data. corridors, establishing a model for further work not only on
more comprehensive collections of messages, but also on
To perform the reasoning necessary for such an alert to be information of other types.
generated, rules of type 4 are executed. The middleware
executes these rules by communicating with the RTS and the REFERENCES
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