THE SILENT SERVICE IS ON THE AIR

How Advanced Communications WUI Revolutionize
Submarine Warfare

Introduction

Communications with nuclear-powered submarines have been historically difficult and are often frustrating, particularly when conducting coordinated task group operations. Operational constraints normally require that submarine communications period be either brief and infrequent while at periscope depth, or slow and unidirectional (shore-to-ship only) while deep and on patrol. The difficulty in talking to us is perhaps one of the (many) reasons why we are called 1he Silent Service. But the introduction of reliable, high-bandwidth communications equipment is putting submarine operations at the cusp of a revolution, and with commercial-off-the-shelf (COT’S) technology, we are doing it now.

History

Modern submarines are designed to operate submerged for extended periods of time; hence, any effective submarine communication scheme needs to optimize the submarine’s ability to remain at search depth. Communications are possible for submarines at search depth, but are currently limited to relatively slow shore-to-ship communications using very low frequency (VLF) and extremely low frequency (ELF) bands. Reception of these signals mandates that the submarine moves slowly and trails a floating wire antenna, which limits the ship’s maneuverability. While this is acceptable for a ballistic missile submarine (SSBN) on patrol, it places too many operational constraints on the attack submarine (SSN).

A better alternative is to have the submarine communicate at periscope depth (PD) and to limit the length of communications. This alternative allows the submarine more tactical freedom while at depth and has minimal impact on submarine operations if the PD periods are kept streamlined and infrequent.

In the mid-l 970s, the Submarine Force inaugurated the Submarine Satellite Information Exchange System (SSIXS). This system used ultra-high frequency (UHF) high-speed satellite communications and it radically improved submarine operations. Now, instead of waiting at PD for hours to copy the broadcast at the VLF rate of 50 baud, the submarine skipper could come to PD, copy his traffic within minutes, and return to search depth. With a data transfer rate of 4800 baud and a buffer of 64 Kbytes, you could copy and transmit up to 15 single-spaced pages at a time in a just few seconds. While this was impressive in the 1970s, the system became severely overtaxed in the information-rich 1990s, and this was especially apparent in submarine battlegroup operations.

Baby Steps

Battlegroup operations are, without question, the ultimate test for submarine communications. In an effort to streamline battle-group submarine communications, the Submarine Force introduced the Battlegroup Information Exchange System (BGIXS). Although this system used the same UHF satellite communication equipment as SSIXS, putting the equipment on the battlegroup flagship eliminated the middleman and speeded up messages getting onto the battlegroup broadcast. Still, the BGIXS system had the same data rate limitations as SSIXS and was, like SSIXS, limited to sending text only. Furthermore, the BGIXS installation on the aircraft carrier was complex, expensive, and permanent. With few units to go around, moving the BGIXS equipment from carrier to carrier became a major proposition. What was needed was something that was simple, cheap, and portable.

The solution was BGIXS II. BGIXS II uses COTS computer technology, some specialized software, and existing UHF satellite communication circuits to produce error-free data transfer of any kind of digital rue. although the system, whose hardware consists of a laptop computer, a modem, and some cables, was designed to be portable, the low cost (approximately $25K) allowed all battle-groups and all submarines to have the system permanently. In addition, the ability to transfer all file types far outweighed the lower data rate (2400 baud for BGIXS II vice 4800 baud for SSIXS). Submarines now routinely send pictures, graphics, even video clips to the battlegroup commander who can use the information in near-real-time to more effectively employ his. forces.

Still, BGIXS Il has limitations. First, the system is stand-alone, requiring an operator to manually transfer information to and from the BGIXS II computer using diskettes (a.k.a. sneakernet). Second, the data transfer rate is very slow when compared to what is required to support interactive graphics and web pages. Third, the system is a victim of its own success, and the increased number of users and data volume threatens to overload it. 1 The next logical step would be a system that would have a data rate to allow web browsing, be compatible with the military’s secure Internet (Secure Internet Protocol Router Network, or SIPRNET), and of course be simple and inexpensive and available now.

A Giant Leap

In early 1999, the Submarine Force experimented with a new system known as Asymmetric Communications (Asymmetric-COMMS) that met all the above requirements. Much like BGIXS II, the Asymmetric-COMMS system uses COTS technology to leverage significant performance improvements from existing communications systems. Asymmetric-COMMS uses cable modems and routers that allow one-way data transfer of 33 kbps with a 2.4 kbps reach back for data transfer and error checking; hence the term asymmetric. Best of all, it costs only $160K per installation.

In addition to maximizing the use of the existing submarine communications infrastructure, Asymrnetric-COMMS allows access to the military’s new SIPRNET network. Much like the cable modem that hooks into the Internet in many homes, Asymmetric-COMMS hooks up to the SIPRNET ashore at the Navy’s regional telecommunications center (NCTAMS). Now, the submarine can communicate directly with anybody in the world who has a SIPRNET address (and vice-versa).

Using the SIPRNET and the attendant e-mail capabilities has a significant impact on how we conduct submarine communications. First, the Internet protocols assure error-free delivery of the messages. Second, the messaging system is entirely automated and keeps track of where messages are and where they have been. Third, it is compatible with the new standard military messaging system that is based on SIPRNET e-mail. Finally, messages no longer have to be screened off the submarine broadcast. Indeed, because of the higher data rate, the submarine can get the information necessary for superior situational awareness in less time. Bottom line: Most of the manual intervention and effort necessary to run a submarine broadcast can be eliminated and the submarine can get more information and spend less time at PD.

And yet, this prompt jump inefficiency is only the beginning. The true power of this enabling technology is in understanding and using the efficiency inherent in the network-centric communications that this medium allows. Network-centric communication allows actions and decisions to take place in parallel vice series, enabling our forces to respond faster and with greater effectiveness. And this power has been recently demonstrated in the Navy’s latest Fleet Battle Experiment.

Revolutionize ASW? WeCAN!

Fleet Battle Experiment ECHO was conducted in March and April of 1999 off the California coast. Part of the experiment was to test and validate the concept of Network-Centric communications as applied to anti-submarine warfare (ASW), and one of the great successes of the experiment was the use of web pages and web browsing technology on the SIPRNET to fight the undersea war. Indeed, the Web-Centric ASW Network (WeCAN) proved to be useful beyond all expectations.

The WeCAN is simply a website posted on the SIPRNET that serves as a central location for ASW information. The information available on the site including such things as environmental, search planning, commander’s intentions, the common tactical picture, and acoustic prediction models. The most exciting parts of the site, however, were the chat rooms. Here were online chats of prosecutions, contact reports, tactical decisions, material issues, and (not the least) communications with submarines at PD. In fact, by using the chat rooms, submarines conducted all their communications at PD without using voice. The commander and submarine were able to routinely pass contact reports, commander’s orders, water space management, even blue-on-blue deconfliction; all without the errors that typically result in multiple “say again” over the voice nets. Thus, the submarine accomplished in 15 to 20 minutes what typically takes an hour or more.

The WeCAN also enabled the planners to develop integrated search plans using all available sensors, and then allowed them to modify the plans in near-real-time to respond to changes in the environment and tactical situation. As one example, planners on the command ship were able to link their computers up with the sonar operators’ computers on a surface ship and collaboratively plan sonobuoy patterns using a shared electronic whiteboard. This allowed the planners to update the plan while the aircraft was en route so that the modified plan could be executed when the aircraft arrived at the station.

The most remarkable event, however, was the efficiency that was created by using the SIPRNET, WeCAN, and e-mail. Information was distributed in parallel vice series, enabling the watchstanders to act independently, quickly, and quietly without waiting for someone else to first handle the information.

Too Good To Be True?

While Asymmetric-COMMS and WeCAN are very powerful technologies, there are limitations. First, Asymmetric-COMMS needs two satellite channels to operate, and only one submarine can communicate at a time. Satellite channels are scarce and obtaining the necessary channels will most likely mean giving up something else. Even if satellite channels are made available, multiplexing and/or timesharing schemes must be worked out in order to have a viable force-wide communication system.

Second, Asymmetric-COMMS and the WeCAN are not programs of record and, as such, are not currently funded or supported with parts and training. Many argue that this method of bottom-up procurement is wrong, and certainly lack of sponsorship raises logistics issues. On the other hand, BGIXS II started out as an unsponsored program and it is now sponsored, largely due to its success in the field and its ability to meet current needs. Asymmetric-COMMS and the WeCAN have a beginning similar to BGIXS Il, and initial indications are that these systems will be even more successful. It’s hard to argue with results.

Finally, the bandwidth for Asymmetric-COMMS, while significantly greater than existing communications systems, is still relatively small by commercial standards. As such, it could easily be overloaded by transferring large amounts of data (mainly 106 graphics). Efforts must be made to keep the data lean and thought must be given to the type of data that is being transferred.

On The Air

To push forward with the submarine communications revolution, I have the following recommendations:

First: Develop an infrastructure to support Asymmetric-COMMS. This would involve outfitting select submarine Broad-cast Control Authorities with Asymmetric-COMMS to SIPRNET gateways and identifying available satellite channels. Shore installations would be approximately $180K each, and low priority circuits, such as SUB OTCIXS, could be used for Asymmetric-COMMS. Additionally, work should continue on developing time-sharing and multiplexing schemes so that several submarines can share one channel.

Second: Equip all deploying submarines with Asymmetric-COMMS. This would phase in Asymmetric-COMMS over a two (or so) year period and would give the greatest return on investment.

Third: Implement and activate the WeCAN on a worldwide basis. The WeCAN is currently a dormant website that gets activated for specific exercises. CTF-12 is planning to permanently activate the We CAN in the Pacific, but more should be done. Each theater ASW force commander should activate and manage a WeCAN site permanently, and should set policy and control the web page design. Memorandums of understanding between the theater ASW commanders and the numbered fleet commanders should be signed that would allow the use of the WeCAN by the battlegroups for area ASW.

Conclusion

[T]rue military revolutions have occurred only twice before in history, and there are strong reasons to believe that the third revolution-the one now beginning-will be the deepest of a11 The Submarine Force is now standing at the cusp of this revolution. The equipment is readily available, but that is only part of what is necessary to be successful. We also need to develop the 107 training, the tactics, and most importantly, the thinking that will enable us to capitalize on this opportunity, and we must have the courage to act now.