Designed to build combat capability and foster cooperation between multinational forces and government agencies, Saxon Warrior 11, an exercise led by the United Kingdom's Flag Officer Sea Training (FOST) organization, was conducted off the southwestern coast of England in May 2011.
Several phases made up the eight-day exercise. The initial phase consisted of primarily single-mission scenarios, including surface, submarine and air combat, and several maritime security operations, such as counterpiracy, and visit, board, search and seizure. The exercise concluded in a full-scale "Thursday War" on May 26.
Although U.S. and U.K. forces responded to fictional geo-political and military scenarios, Saxon Warrior gave the "Bear Aces" of Carrier Airborne Early Warning Squadron 124 (VAW-124) the chance to carry out sustained and coordinated military operations with NATO partners. As part of the exercise, multinational aircraft squadrons practiced in low-level flight operations, air-to-air engagements, long-range strikes and close air support of surface combatants.
Other U.S. forces included Carrier Strike Group Two (CSG-2), Carrier Air Wing Eight (CVW-8) and Destroyer Squadron 22 (CDS-22), while United Kingdom participation involved various elements of the Royal Air Force and Navy.
To facilitate the integration of U.S. forces into the existing U.K. link architecture, the Space and Naval Warfare Systems Center (SPAWARSYSCEN) Pacific's network design team and the Joint Data Link Management Organization (JDLMO) created a Joint Tactical Information Distribution System (JTIDS) network library (JNL) for Link 16 to allow a common communication structure between all surface, air and land assets. With Link 16, military aircraft, ships and ground forces can exchange their tactical picture in near-real time. Link 16 also supports the exchange of text messages, imagery data and digital voice communications.
Link Architecture for an Airborne Early Warning Squadron
JTIDS was developed to improve previous datalinks, bringing increased bandwidth, combat redundancy and greater geographic coverage. Through the use of a frequency agile receiver-transmitter and time sharing, large numbers of individual units can participate, monitor or relay tracks with no time delay. The key to this versatility lies in the software algorithms, which assign transmit and receive times, as well as the ability to select the data to be transmitted during these periods.
There are several versions of JTIDS software, each tailored to various mission requirements. Every version is assigned a number within the JNL system. For example, a JTIDS network library designed as a primary air defense datalink will have increased bandwidth and transmission time for units possessing air surveillance radars and increased priority for the transmission of return tracks from interceptors to controlling units.
On the other hand, a ground-centric JNL, where air superiority has been achieved, will trade air defense priorities for increased ground unit participation with an accompanying shift in bandwidth availability. Keep in mind that compatibility between different JNLs is possible, with smaller "nodes" being established within the entire network. In addition to being network specific, the JNLs also use software specific to the participating platform.
While it may be an oversimplification to say that the United Kingdom uses the JTIDS as its primary air traffic control network, it is accurate to say that it plays a major role in providing big-picture oversight regarding flight safety and national defense. As a result, JTIDS operations in the U.K. are highly regulated by the JDLMO, and non-compliance with procedures results in expulsion from the network. In fact, prior to conducting any link operation in the U.K., a platform must be granted permission to operate by the U.K. Civil Aviation Authority.
The architecture of JTIDS in the U.K. is similar to that of a U.S. Navy carrier strike group with network time reference (NTR), a highly accurate system time used to coordinate transmission and receive times, held by remote terminal modules (RTMs). Participants contributed either through direct contact with the remote terminal module or through units acting as relays or data forwarders.
By direction of the JDLMO, surface combatants used airborne assets as "air bridges" to provide an extended line of sight. These air bridges consisted primarily of the E-3D airborne warning and control system (AWACS) and E-2C Hawkeye aircraft, but any Multifunctional Information Distribution System (MIDS) capable aircraft can provide the relay needed for entry and full participation in the network.
The JNL specifically constructed for Saxon Warrior met all of the information exchange requirements of the participating units, but also remained within the constraints of the U.K. Frequency Clearance Agreement, as well as the operating restrictions of the U.K.'s tactical datalink (TDL) policy.
The Saxon Warrior JTIDS network library and platform specific loads were released for U.S. assets in the weeks preceding the exercise, but arrived too late to be included in a scheduled link exercise prior to mobilization. As a result, the first operational trials between U.S. units occurred during the trans-Atlantic voyage; no interoperability tests took place until arrival in the exercise area.
Tests between U.S. forces were marginally successful, with the USS George H. W. Bush (GHWB) acting as the network time reference node. Test metrics were measured through Fine Sync indications at individual terminals and the successful transmission and receipt of precise participant location and identification (PPLI) symbols and JTIDS voice communications (J-Voice).
Although all participants received hardware indications that synchronization was achieved, no consistent level of communications existed between units. In the E-2C, hardware indications of Coarse Sync were displayed without PPLI symbols, but two-way voice communications were possible using the voice circuit. This condition was contrary to the system knowledge possessed by the typical crew member. Additionally, where hardware indications showed Fine Sync, voice communications were not possible even while PPLI symbols were present.
Line-of-sight considerations because of range prevented direct entry of surface assets into the U.K.'s link architecture. To maintain a recognized air and maritime picture, the aircraft carrier assumed the role of the network time reference node when airborne assets were not available. Without line of sight to the RTMs, this surface node was able to operate independently in several operating areas without interfering with frequencies used by shore-based facilities.
Upon commencement of flight operations, the intent was for the E-2C Hawkeye to establish itself in the link with the shore remote terminal module at Tregantle Fort in southeast Cornwall. GHWB relinquished its role as the NTR and entered the U.K. datalink architecture via the relay option incorporated in the Hawkeye's software load.
As MIDS aircraft would launch, the connectivity between the GHWB and remote terminal module was further enhanced by virtue of the network configuration. The air bridge would allow the transfer of information as long as the E-2C could receive system time from the remote terminal module and transmit that system time to the GHWB.
With these two single points of failure and an untested interface between forces, the stage was set for troubleshooting over several variables and operating conditions. Of note, it was discovered only during the last few days of the exercise that one of the four E-2C aircraft was unable to transmit JTIDS data because of a damaged transmission line.
Another aircraft could not transmit because of a faulty control unit. The two aircraft were able to "passively" enter JTIDS, but did not relay any timing data or their own precise participant location and identification symbols.
Additionally, reliability issues with the RTM at Tregantle Fort prevented timely troubleshooting for the E-2C system's degradation.
Problems that arose during the first few days of Saxon Warrior led to the systematic analysis of various hardware and software configurations, as well as contact with SPAWARSYSCEN Pacific regarding the stability of the E-2C's JNL. While link connectivity was achieved between the carrier strike group and U.K., it was unreliable and did not provide a useful tactical picture.
Specifically, it was apparent that the E-2C was not relaying PPLIs from surface combatants to the U.K., and the carrier strike group did not receive any air tracks present in the U.K. datalink. After reviewing the parameters of the existing JTIDS network library, SPAWARSYSCEN Pacific released a revised version of the software, ensuring that a PPLI relay feature was entered and activated. This new software configuration proved moderately successful, and with the discovery of the faulty JTIDS equipment in the E-2C, link operations improved. However, with the end of the exercise near, limited data were collected to prove the validity of the new software build.
The successful integration of non-organic nodes with pre-existing data architecture is the key component to any effective command, control, communications, computers and intelligence (C4I) structure. To achieve successful integration, two single points of failure were incorporated to bring the GHWB Strike Group into the U.K. datalink. Even under the most ideal situations, this is a risky proposition, and combined with a lack of reliable communications between shore facilities and the E-2C aircraft for troubleshooting indications on both sides of the links, there was little that could be done at the operator level.
The incorporation of reliable very and ultra high frequency voice communications between the E-2C and ground stations is an absolute necessity. Additionally, communications between the ground station command elements and remote equipment locations would greatly decrease the time needed to troubleshoot equipment and increase the time allotted to focus on software anomalies because of the limited endurance of the aircraft.
While the JDLMO liaison officer aboard GHWB proved invaluable in relaying information to the remote terminal module when UHF communications failed, the lack of sufficient operational evaluation of the JNL and common technical language between aircrew and ground operators did not contribute to the success of this operation. Overall, the successful execution of this exercise was generally achieved in spite of, rather than because of the quality of the datalink. While conducting large force operations, U.S. forces usually create a standalone datalink for their own operating area, with minimal interaction with CONUS shore-based facilities required. In the U.K. operational environment, this is not an option because of the strict regulation of Link 16 operations. To improve the performance of JTIDS during joint exercises, prior planning, combined with dedicated troubleshooting, are two simple solutions to the problems encountered during Saxon Warrior.
While an embarked JDLMO liaison officer greatly helped with the integration of carrier strike group assets with the U.K. datalink structure, on-site representatives from the strike group were not present at any of the remote terminal module nodes or any other ground stations. Specifically, a representative from the E-2C squadron familiar with the operation of JTIDS would have provided the real-time assessment needed for various troubleshooting steps that are unique to the E-2C, and the common technical language that was lacking could have been mitigated through this liaison officer.
Prior to the commencement of the exercise, operational testing should be performed through the use of an actual E-2C to gauge the compatibility of the software load. The role of the liaison officer would be integral to this phase as well, providing specific technical characteristics which would aid in the resolution of any problems that might arise. Attendance and participation of a liaison at the initial planning conferences and through the execution phase would provide a single point of contact and technical expertise to bridge the gap between the strike group and allied forces.
Optimally, these recommended solutions would contribute to the overall success of JTIDS operations. If this is not feasible, even implementing one of the recommendations would pay great dividends toward improving interoperability between systems and foster the spirit of cooperation necessary to the success of any allied operation.
Lt. Dennis A. Szpara is an E-2C naval flight officer with the VAW-124 "Bear Aces."