Seamless communications: the challenge of tactical command and control

Affordability, interoperability, COTS, easy connectivity between services and command echelons, and support for mobile forces over a wide zone of battle are only a few of the qualities that top military leaders will require in their new communication systems

Jan 1st, 1997
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Affordability, interoperability, COTS, easy connectivity between services and command echelons, and support for mobile forces over a wide zone of battle are only a few of the qualities that top military leaders will require in their new communication systems

By John Rhea

One of the imperatives of the modern combat leader is enabling his forces to exchange information easily between all services, at all echelons in the chain of command, and in all forms of information - voice, textual data, graphics, images, and video.

It follows that the overarching requirement of future tactical command, control, and communications systems is to offer seamless operation among a mixture of heterogeneous hardware systems so that the flow of information from the top commanders to the individual soldier in the field will appear transparent to everyone along the way.

Planners at the U.S. Department of Defense (DOD) say their future communications system must at least be able to provide wide- and narrow-band data and voice communications to mobile forces throughout a battlefield at least 62 miles (100 kilometers) deep, with seamless connectivity between ground, air, and naval elements dispersed as far away as 124 miles (200 kilometers). DOD officials outline this requirement in their 1997 defense technology plan for information systems, updated late last year.

The "on-the-move," or OTM, part of this requirement means that communications systems must be able to link squad-level units and even individuals into a mobile communications environment, and poses the most severe technical challenge.

The communications media will be wireless battery-operated devices bearing a remarkable resemblance to cellular telephones, laptop computers, and many other new products of a booming consumer electronics industry.

The DOD master plan for information systems also stresses affordability and interoperability with U.S. and foreign commercial infrastructures, thus offering substantial opportunities for implementing commercial off-the-shelf (COTS) technologies.

DOD perception of the role of the commercial telecommunications industry supports this view. "The military is leveraging literally billions of dollars of commercial investments in achieving objectives by active participation in standards bodies, promotion of commercial development, and appropriate DOD-specific research," the updated report notes.

Specifically, DOD officials are looking for industry help in 11 technology areas:

(1) Communications equipment interoperability in multi-vendor, multi-network, joint/combined force, and commercial environments;

(2) framing protocol for tactical Asynchronous Transfer Mode (ATM) links;

(3) protocols for high-rate data communications in subscriber loops subject to sporadic disturbances;

(4) forward error correction for tactical ATM;

(5) building a fully Internet-compliant tactical packet network using legacy radios such as the Single-Channel Ground and Airborne Radio System;

(6) integration of data and voice over low bit-rate links;

(7) heavy multipath and deep fade effects;

(8) security;

(9) development of network management and control protocols that can withstand jamming attacks;

(10) increases in transmit efficiency and jam resistance; and

(11) development of conformal arrays for airborne and on-the-move antenna applications.

To tackle these technical challenges, DOD officials have launched three advanced technology demonstration (ATD) projects, one at each service.

Under their Data/Voice Integration effort, Navy officials will explore the technology to provide integrated services in low-rate data tactical communications systems using common hardware and networks. The idea is to achieve what DOD leaders call "nearly direct industrial production" of deployable systems, taking into account the problems of commercial solutions at the low data rate of 2.4 Kbit/s with high error rates introduced from outside factors.

Army officials have a somewhat more ambitious project in their Digital Battlefield Communications effort in which their forces must maintain communications with mobile units.

Army leaders also hope to rely heavily on COTS technology. "These new services leverage services introduced to the commercial world and will supplement some and replace other legacy communications systems," the report notes.

This ATD began in 1995 and introduced a wideband packet radio called the Surrogate Digital Radio to add capacity to the tactical Internet. The next step is to integrate commercial ATM technology into such systems as the Army`s Mobile Subscriber Equipment to provide "bandwidth on demand."

The ATD will also research Direct Broadcast Satellite technology through a series of coordinated experiments intended to develop a global broadcast services capability for all the services.

Also, to extend ATM multimedia services to forward tactical units, Army technical managers will prototype and test a "radio access point" high-capacity trunk radio that provides mobile communications through a wideband airborne relay communications package. Army experts will test the airborne relay initially at a bandwidth of 45 Mbit/s and then at 155 Mbit/s for moving units and 600 Mbit/s for stationary units.

The Air Force ATD, known as Information for the Warrior, aims at meeting the extremely wide bandwidth requirements to support next-generation mission planning. This means some combination of undersea and land-based optical fiber cables and satellite communications. For the ATD, the Air Force will experiment with communications to tanker and airlift aircraft.

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The future U.S. military communications system must provide wide- and narrow-band data and voice communications to mobile forces operating over a wide area, with easy links between ground, air, and naval elements.

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The handheld radios of tomorrow`s infantry soldier won`t be simple walkie-talkies. They must be difficult to detect, and be able to send voice, data, video, and still images.

BBN demonstrates wearable LAN

Engineers at BBN Corp. in Cambridge, Mass., last month demonstrated the initial capabilities of a local area network (LAN) that individual soldiers can wear on the battlefield to enhance their situational awareness. This LAN would integrate a variety of sensors with commercial off-the-shelf microprocessors and data links into a Warfighter Monitoring System.

The effort arose out of DARPA`s Smart Modules Program, and BBN`s role is to develop a prototype known as the BBN MicroPathfinder - a wearable, visual communications and navigation system designed to support the dismounted soldier.

The system consists of two elements: a small hand-held display that shows a map and graphical user interface, and a wearable computer attached to a Single-channel Ground and Airborne Radio System radio. The two components communicate with each other via the low-power wireless BodyLAN, which BBN engineers developed in recent years with a combination of its own money and DARPA support (originally from the Tactical Information Assistant Program).

The capabilities demonstrated last month, both of which originated in the Smart Modules project, are navigation with shared mapping and communications capabilities and tracking support using the global positioning system.

In June BBN executives expect to demonstrate a personal inertial navigation support system. Future planned additions include health monitoring sensors (body temperature, pulse rate, etc.), wireless earphone and microphone devices for voice communications, and weapon monitors to track their use or loss.

The idea behind BodyLan centers on its open-system architecture to accommodate a variety of personal computers, sensors, and communications equipment. The architecture consists of a star network with a central hub and a full duplex transceiver with a 90 Kbit/s aggregate data rate RF link. Power consumption is in the tens of microwatts.

BBN engineers expect to begin seeking suppliers next summer for the electronic components necessary to move this technology out of the laboratory and into operational use. - J.R.

Speakeasy: `PC of radios`

A key component in the tactical command and control systems of the future, the Speakeasy next-generation tactical radio, is to be more than "just a radio." This is to be a multifunction communications system with considerable non-military applications that its supporters call the "PC of the radio world."

The joint services research and development program by the Air Force`s Rome Laboratory in Rome, N.Y.; the Army`s Communications and Electronics Command at Fort Monmouth, N.J.; and the Defense Advanced Research Projects Agency in Arlington, Va., will compete at the module level.

Among the technologies DOD officials are looking for are memory, signal processing, software, I/O interfaces, programmable filters, routing/networking, encoding/decoding, and RF engineering.

The current phase focuses on developing the architecture for a six-channel multiband, multimode radio, of which four channels are programmable, one is a global positioning system receive-only channel and the sixth is a commercial cellular phone channel.

The bus backplane will be the Personal Computer Memory Card International Association or PCMCIA format. Production units are expected to weigh 30 pounds, occupy less than half a cubic foot of space, and require 60 watts total power when Speakeasy becomes available around the year 2000.

Because the channels are reprogrammable in bands anywhere from 2 MHz to 2 GHz, the Speakeasy units are expected to be compatible with Single-channel Ground and Airborne Radio System and other existing systems and also accommodate cellular telephony, air traffic control, and other civil aviation applications. - J.R.

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The Speakeasy radio, which this early prototype depicts, will be a land-mobile radio as well as a satellite navigational device with the ability to communicate over cellular telephone bands.

Canadian system phasing in COTS

Experts are incrementally phasing commercial off-the-shelf (COTS) technology into Canada`s Tactical Command Control Communications System (TCCCS), known as Iris, which launched in the pre-Cold War era in 1989 before the current trend away from rigid military specifications.

This is a $1.4 billion (Canadian) program due to be completed in 2000 to outfit six brigades of the Canadian army for overseas deployments in peacekeeping missions.

The prime contractor and system integrator for Iris is Computing Devices Canada (CDC) in Calgary, Alberta. Operational systems engineer Kim Grant explains that the first move toward COTS was the use of industrial-grade parts in the switching boxes. However, company engineers decided that some critical components, such as the digital signal processors (DSPs) would have to continue to meet mil specs.

The Canadian system is a good example of seamless communications spanning radio, telephone, cellular, and satellite links, mostly for mobile land forces. The entire land force amounts to just one division, but it spreads over a large geographic area. This includes 6,400 "platforms," including 10,000 combat net radios for squad-level units and 4,000 hand-held radios. About 200 of the units will go into helicopters and another 50 to the Canadian navy.

This is also a turnkey project with CDC integrating a variety of British and American hardware and software and delivering the finished systems to six user sites, where company experts will conduct training and provide logistics support. Shipments of the hand-held units, produced by Litton Data Systems Division in Woodland Hills, Calif., and identical to U.S. Army units have been in progress since 1991. Deliveries of the vehicle-mounted units will begin next August.

Other COTS items include the long-range satellite terminals (C, Ku, and X band) from TRW in Redondo Beach, Calif., the Unix operating system from SCO in Santa Cruz, Calif., Microsoft Office from Microsoft Corp. in Redmond, Wash., for the message terminals, and the Genamap digital mapping system from Genasys 2 in Fort Collins, Colo.

Last April the Harris Corp. RF Communications Division in Rochester, N.Y., won a $16 million subcontract from CDC to provide the HF transceiver systems (real-time voice and data) in portable manpacks, vehicular radios, and larger systems integrated in protective shelters.

An innovation of the Canadian system is dual fiber optic trunk lines between vehicles and within communications headquarters. This is an interconnected packet switching system built to NATO standards and produced by Northern Telecom`s British operations. In the field the systems operate at 2 megabits over distances of 15 to 20 kilometers and within headquarters operations, at 8 Mbit/s over distances of half a kilometer or less.

Grant says he expects to achieve 153 Mbit/s in the future using ATM and without changing the fibers. - J.R.

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The Canadian Iris communications system from Computing Devices Canada, will span radio, telephone, cellular, and satellite communications links for mobile land forces.

Fibre Channel and ATM in brief

As the embedded computational power in weapon systems and commercial information processing systems grows to meet ever-demanding user-imposed requirements, the data links that route information within the systems and to the outside world are struggling to keep pace.

A rule of thumb for this situation is known in the industry as "Amdahl`s Law" (named for former IBM executive Gene Amdahl), which states that a megabit per second of I/O capability is necessary for every million instructions per second of processor performance.

With gigabit processing speeds necessary for such advanced military applications as imagery, the data links threaten to become bottlenecks between the source and the soldier on the battlefield who needs it.

There are two approaches to this problem: Fibre Channel and the Asynchronous Transfer Mode (ATM). Both have their roots in commercial data processing and thus offer sufficient economies of scale to make them attractive to the military.

Fibre Channel (the name is somewhat misleading since it includes copper wires as well as optical fibers) originated in 1988 from a decision by the American National Standards Institute (ANSI) to seek a new serial communications link with adequate bandwidth and distance capability to meet growing I/O requirements.

A supporting industry organization, the Fibre Channel Association (FCA), says the Fibre Channel market grew from $2 million in 1993 to more than $50 million last year and will accelerate to $2.5 billion by the year 2000.

Fibre Channel bridges the gap between the two principal data communications methods: channels and networks, note experts at Systran Corp. of Dayton, Ohio, who prepared an explanation of Fibre Channel for the FCA.

A channel is a point-to-point link between processors or peripheral devices, which is hardware-intensive, has lower overhead than a network, and is limited to fixed links. Channels can disseminate data broadly among nodes such as file servers and workstations, but are software-intensive and thus have higher overhead than networks.

The Fibre Channel solution is a hybrid of channels and networks in which an intermediary, known as a fabric (also called a "cloud"), serves as a generic transport mechanism.

All a Fibre Channel port has to do is manage a simple point-to-point connection between itself and the fabric. The transmission is isolated from the control protocol so designers can implement different topologies, such as point-to-point links, rings, multidrop buses, and crosspoint switches. The fabric is also self-managed.

FCA officials compare this approach to a telephone exchange, which serves as the intermediary between telephones, fax machines, and modems. Fibre Channel can support 16 million nodes on a single fabric at distances as far as 6.2 miles (10 kilometers) per link. Currently supported data rates range from 133 Mbit/s to 1.06 Gbit/s. Fibre Channel adapters and switches are now in production.

ATM, meanwhile, is a scalable communications technology in which all traffic (data, voice, and video) flows in cells. Each 53-byte cell consists of two parts: a header of 4 bytes plus a 5th check byte that routes the message to its destination and a 48-byte payload.

ATM is scalable because it can chop any size transmission into 53-byte cells and send at whatever speed the system operates, from 64 Kbit/s to 2.4 Gbit/s. ATM also has its supporting organization, the ATM Forum, founded in 1991.

ATM is compatible with existing networks, such as Ethernet and the Fiber Distributed Data Interface, better known as FDDI, says John Grant, development director at K-Net Ltd., in Yately, England, and also serves the same function as a telephone exchange.

In ATM, the connection between the terminal and the communications system is specified as a standard known as the User-Network Interface. Each user has a cable from his computer to an ATM network, and these networks don`t have to be homogeneous; different terminals can have connections at different speeds.

Before he can use the ATM network, however, the user must create a "virtual circuit" to the desired destinations. This is done in software and only has to be done once. This is called a "connection-oriented" approach (like the telephone system) and all subsequent connections are done entirely by hardware.

Therefore, once the path has been established, designers can upgrade the hardware at will. This technology is part of local area networks in university campuses in Europe and the United States. - J.R.

Rome Lab developing communications planning tool

When future American forces conduct an overseas mission such as the current Bosnian deployment, they will have a mathematical model to enable them to tailor their communications systems to the local situation and the available assets.

That`s the goal of a five-year, $24.5 million program at the U.S. Air Force Rome Laboratory in Rome, N.Y., and known as the Joint C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance) Architecture Planning/Analysis System.

It`s a 1997 new start for which a prime contract is set for April, but already all nine of the unified commands and such other DOD agencies as the National Imaging and Mapping Agency and the National Security Agency have signed up to use it when it becomes available. The laboratory is currently writing the statement of work for the project.

What the users will get is a set of essentially COTS software running on Unix-based systems to do their C4ISR planning before the deployment, explains Michael Wessing, chief of Rome Lab`s Command Development Branch.

This software package will be hardware-independent, and Wessing says he anticipates that future versions will also be able to run on Windows NT. The package will also be compatible with DOD`s Defense Information Infra- structure. All the users need is their own server.

In operation, the system would provide a graphics interface to hook into existing databases to let the users know what communications are already available in theater and what they will have to bring with them.

The project is funded incrementally to make limited features available as soon as possible, and Wessing says he anticipates that imagery will be the first function. The tool set will eventually access all facets of the global command and control system. - J.R.

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