The client, Cubic Corporation, supplies realistic live combat and virtual training systems for military forces. Some of its recent projects require a number of different locations and simulations to be interlaced to create a multi-role simulation. In linking these together to create a virtual theatre Cubic is able to offer a truly realistic scenario that enhances Warfighting capabilities and mission readiness. In this application the Mercury system is primarily designed to accommodate radio’s and link together a number of radio conferences and analyst workstations over IP. The system is ultimately scalable allowing for expansion to take in any number of workstations. In this guise Mercury been an enabling technology in the Initial-Homestation Instrumentation Training System (I-HITS) and the Alaska Training Range Evolution Plan (ATREP) program’s.
Cubic Corporations Defense and Security Group supplies realistic live combat training systems for military forces and virtual training systems, advanced laser technology and transportation security systems. Cubic's defense communications business provides search-and-rescue avionics and tactical data links and surveillance receivers for "C4ISR" applications. Cubic's government services businesses provide live, virtual and constructive training services for defense and security agencies, as well as force modernization, battle command training and education, weapons effects modeling, and maritime security services.
Cubic Corporation has developed a number of new simulation and training products over the past few years and these have generated a need for radio communications to be passed between multiple locations over an IP network. Flexibility of design and scalability are key drivers of the system due to its need to adapt and evolve to the simulation needs of the many branches of the military.
The challenge the system posed was that a number of operators needed to be able to listen to any combination of 16 radio conferences each with any number of participating radio’s. Every operator needs the capability to speak to any radio, listen to any radio and hear any other operator who speaks. This must be done in such a way that the number of available IP channels is never entirely used up thus ensuring that these speak and listen routes are always available.
The system must operate with the operators using Push-To-Talk (PTT) to speak to a radio, they must also have ‘safety of flight’ side tone at all times (see explanation) and all communications, speak and listen must be recorded.
Trilogy’s solution has a number of independent systems linked together, each system comprising an MIU typically hosting 16 radios each in their own conference and a number of operator workstations. Each workstation consists of a PC or laptop running a virtual control panel via a full length PCI card or a USB adaptor. The 16 radios hosted by each MIU equipped with either a E&M (Ear & Mouth Board) and AEB (Audio Expansion Boards) cards or RIB cards (Radio Expansion Board) can be located in almost any geographic location with no requirement to be near each other. The signals are instead passed back to a central MIU through third party E&M equipment.
Each workstation’s virtual panel hosts up to 16 radio conferences, the exact number being determined by the number of radio’s connected to the system. As a result of there being no limit to the number of operators on the system a conventional multicast environment could potentially run out of DSP’s. Therefore the system has been specifically configured with each radio conference split into a speak conference and a listen conference where all of the speak activity is aggregated and then retransmitted onto to listen conference. This means that the number of channels remains static and therefore remains constant.
Operator workstations always have one channel set listen which means that as long as one workstation is initialized then all of the radio conferences are open to multicast traffic. All conferences are set to display the presence of audio by ‘Dimming’ regardless of whether that conference is actually being listened to although all conferences that are initialized are recorded by Stancil recorders.
In this application all speak functions are facilitated by the use of a PTT (Push To Talk) switch which is either connected to the work stations serial port or in the latest equipment configuration to the GPI of the PCI card or USB adaptor.
One final key element of this system is the provision of ‘Safety of flight sidetone’ which is of critical importance to Cubic as these are live combat and virtual training systems for military forces. The system delivers configurable ‘Safety of flight sidetone’ where users can manage which ear it is delivered to, at what volume and for how long.
To assure themselves that their voices are being transmitted correctly, controllers speak into their headset microphone which sends the voices through a range of multiplex communications equipment and back into the headphones of controllers - a facility known as "on-air sidetone."
When controllers hear their own voices in their headphones, they have an added level of confidence in knowing that their equipment is functioning and that their voices are reaching pilots. Without the sidetone facility controllers might shout, as if speaking into a telephone without hearing your own voice.
Source: ComputerWeekly.com; The Swanwick air traffic control centre "sidetone" problem, 01/272000
JT3
JT3 (JT3 is a joint venture company created for the purpose of providing engineering and technical support to the J-Tech (Joint Range Technical Services) test) has a similar configuration as Cubic, notably used during USAF’s “Red Flag” aerial combat training exercises, both at Nellis Air Force Base, Nevada and Eielson AFB, Alaska.
RED FLAG is an advanced aerial combat training exercise hosted at Nellis Air Force Base, Nevada and Eielson Air Force Base Alaska. Since 1975, air crew from the United States Air Force (USAF) and other U.S. military branches and allies take part in the exercises, each of which is six weeks in duration.
The Red Flag exercises, conducted in four-to-six cycles a year by the 414th Combat Training Squadron of the 57th Wing, are very realistic aerial war games. The purpose is to train pilots from the U.S., NATO and other allied countries for real combat situations. This includes the use of "enemy" hardware and live ammunition for bombing exercises within the Nevada Test and Training Range.
