Military planners are aggressively developing network-centric warfare platforms that use wireless communications as a force multiplier. The aim of these programs is to provide warfighters with the best equipment and technology to achieve tactical dominance as soon as practical.

Software virtual networks (SVNs), built with emulation technology, enable wireless network designers to evaluate new components and technologies faster and at much lower cost than previously possible. SVNs are high-fidelity emulations of physical networks - exact digital replicas of real network components. Until now, there has been no efficient, scalable, and low-cost method for design and analysis of mobile wireless network systems.

The Net-Centric Kill Chain Training Scenario. The design objective of this kill chain is to enable the sequence from initial intelligence discovery to final missile launch to happen in a matter of minutes.
A software program called EXata creates SVNs with high levels of realism. Any hardware, software, or human user connected to the SVN is not able to tell the difference between a real network component and its emulated counterpart.

This high level of realism makes SVNs suitable platforms for operations training, much like the flight simulators used to train pilots. The figure depicts a net-centric kill chain training scenario. In this example, the chain of command starts with on-the-ground troops and moves through intelligence links like satellite and predators, and then out through satcom links to the weapons systems. The design objective of this kill chain is to enable the sequence from initial intelligence discovery to final missile launch to happen in a matter of minutes. It covers a wide geographical area and a broad spectrum of roles. Leveraging the same SVN used to design the kill chain as the training platform adds substantial cost efficiencies and dramatically shortens time to deployment.

An SVN that delivers exact digital replicas shares the following characteristics with the real network it replaces:

  • Same Behavior and Logic. For instance, a real router can't discern between emulated network nodes and real ones. To achieve this, the protocol stacks, middleware, network-centric services and applications in an emulated environment must be equivalent to the real network systems.
  • Same Interaction and Language. Same interaction means the response from an emulated network has the correct content, or language, including byte order, packet contents, packet headers, etc. An exact digital replica allows the real network to interact with it on whatever layer of the protocol stack is called for. In other words, emulators must support cross-layer technologies.
  • Same Response and Timing. Response time is critical in emulation. In order to respond like a physical network, the emulation must process network events no slower than, or no faster than, real time. The concept of timing synchronization granularity means that the emulation must represent packets and time at a level fine enough to perfectly synchronize with the external world.

A software or hardware system developed or evaluated in EXata plugs into a real network, because the code that runs in EXata can also be migrated into the deployment environment. That means that no additional man-hours are needed to rebuild a prototype system in the software so that it can run in a real network.

When emulating a network, you can examine network performance on three levels or planes:

  • Network Effects - The Network effects plane looks at the network in terms of aggregate performance, such as end-to-end delay and throughput. Looking through the lens of Network Effects, the emulated network is a black box whose responsibility is limited to determining latency for each packet transmitted by the applications. This mode is useful for embedding an emulated network between two or more physical hosts running applications. The most common use case of this mode is observing the performance of applications or network services under the diverse and varying network conditions. The Network Effects Plane supports the Same Behavior requirement of emulation.
  • Protocol Effects - The Protocol Effects plane looks at network performance based on protocol logic. In the Protocol Effects Plane, network performance is determined by routing, Medium Access Control, data rate control, topology management, and traffic flow shaping. The Protocol Effects Plane is the only plane through which you can view network performance with some model abstraction. An abstracted protocol model is a lower fidelity approximation of the true protocol.
  • Network Services - In the Network Services plane, the emulation processes packets for applications and middleware by receiving, sending, decoding, and encoding, all without the rest of the network noticing that emulation is taking place. The software runs services or middleware in their native source code within the emulator. The source code of these services can be ported, with very little to no modification, into the emulator.

Emulations developed during test and evaluation of alternative network design solutions give operations teams a ready-made platform with which to conduct highly realistic scenario training exercises.

This article was contributed by Scalable Network Technologies Inc., Los Angeles, CA. For more information, click here .