Mathematical model of IRIS replication mechanism for the simulation of tactical networks

Abstract

The Multilateral Interoperability Programme (MIP) was established to promote more successful and better harmonized operational functions for international peace-keeping forces. The C2IEDM/JC3IEDM (Command and Control Information Exchange Data Model) ensures the interconnection of Command and Control Information Systems (C2ISs) throughout all levels, from the corps down to the lower ranks. The usability of C2ISs highly correlates with the capacities of data information carriers, and the need is growing for greater capacity and reliability of transmission media and cryptographic message security. Simulation of tactical networks is an important task in planning military missions. Such methodologies assure a higher probability of success during critical tactical operations. This article focuses on a new radio network modeling method for the C2IS, which is verified by the OPNET simulation environment. This modeling method can be used in tactical radio network planning and optimization processes.

Introduction

Today, the world faces many crises that demand military intervention with international peace-keeping forces. The Multilateral Interoperability Programme (MIP) was established in 2001 by fusing the predecessor MIP with ATCCIS NATO in order to advocate successful and harmonized operational functions for international peace-keeping forces. The aim of the MIP is to achieve international interoperability for Command and Control Information Systems (C2ISs) at all military levels, in order to support multinational, combined, and joint operations, and the advancement of digitization in the international arena [1].

C2ISs, working within the MIP, are founded on databases. Data flowing between databases are defined by the unique C2IEDM (Command and Control Information Exchange Data Model). JC3IEDM is an evolution of the C2IEDM standard that includes joint operational concepts. The overall goal of JC3IEDM is to specify the minimum dataset that needs to be exchanged during coalition or multinational operations. Each nation, agency, or interested community is free to expand its own data dictionary to accommodate additional information exchange requirements, with the understanding that the added specifications will only be valid for the participating nation, agency, or interested community. This data model enables users to decide which information to provide, to whom it should be given, and when [1]. The success of this C2ISs is highly correlated with the capacities of the data information carriers. Modern military operations have an increasing need for greater capacity and reliability of transmission media and cryptographic message security. We focus here on tactical radio networks as a communications infrastructure [16], where most exposed problems are limited to bandwidth, long round-trip delays and the influence of terrain and node mobility on radio link conditions. Simulation of tactical networks is an important task in military mission planning. Such methodologies assure a higher probability of success during critical tactical operations.

Along with the evolution of computer and communications technologies, systems have also rapidly developed to aid the tactical planning process. Existing literature [17], [18] introduces tactical planning expert systems based on expert databases and soft computing methodologies, but does not consider the communication viewpoint of mission planning, which is very important in contemporary combat. One of the early papers about tactical radio systems simulation presents a solution [19] where a specialized FORTRAN program is developed to simulate radio propagation effects, interference, SNR, etc. Similar capabilities also use state-of-the-art communications simulation tools such as the OPNET Modeler [4], used as a basic tool in our work. The results from such simulations can be used when evaluating the performance of tactical communication networks [20].

There are two concepts when planning tactical networks. The first concept is based on simulating those communications systems where the communications infrastructure and tactical activities are modeled by the simulation environment. The best-known representatives of this concept are the NETWARS and INCOT tools, which were developed specifically for the simulation of military tactical networks. NETWARS [5], [7], [9] is the most advanced tool and enables simulation of different tactical simulation scenarios by using diverse combinations of tactical network devices and military concepts. The second tool, INCOT [6], [8], is a specialized tool for the optimization of communications networks. Both are based on the well-known OPNET simulation tool. The problem with this concept is not in modeling of the communications infrastructure, but in modeling of the data sources in the application layer protocols used by C2IS. This can be a very difficult task. Simplified stochastic traffic models are normally used. The second concept of tactical network planning is System-In-The-Loop (SITL), which combines parts of real tactical, networks (tactical computers with C2IS software) with simulations (simulated communications infrastructure). Such a solution is given in [10]. The problem with this solution is that real C2IS equipment must be available for simulation purposes.

It is difficult to develop universal tools for tactical network planning because armies usually use different C2ISs and communications infrastructures. This is the reason why we have developed our own system, whose concept relates to the first of the above-mentioned concepts. This paper presents the research project’s results from C2IS’s modeling. The intention of this project is to develop methods for optimizing hierarchical tactical radio networks. The C2IS of the Slovenian army is based on a mechanism for controlled replications (IRIS replication mechanism) between C2IEDM databases. We have developed a mathematical model for the mapping of data sources, along with the contracts of the IRIS replication mechanism to network traffic in OPNET communication simulation tool. The mathematical model has been incorporated into the TPGen application. This application provides a user-friendly tool for preparing tactical network simulations, entering required parameters of military units and radio devices, defining data sources, and defining contracts between military units.

This paper is organized as follows: Section 2 starts with a summary presentation of C2IS, as used in the Slovenian army. Section 3 briefly presents the OPNET simulation environment and describes the possibilities of modeling data sources in different ways using this simulation tool. Then, a mathematical description is given for modeling IRM contracts and application delays. These models are used by the TPGen application to map IRM application traffic to the OPNET environment. The use-case of OPNET simulation for tactical hierarchical radio networks is described in Section 4. Section 5 contains the simulation results of a test tactical network, which were validated by a mathematical model developed for mapping IRM contracts to OPNET traffic generators. Section 6 draws conclusions and guidelines for further work.