Data Links within C4I

Data Links within C4I SUMMARY This paper explores how Tactical Data Links in general and Link 16 in particular, have evolved to meet the interoperability challenges of modern C4I systems. Having been originally developed around specific operational needs for particular battlespace requirements, TDL standards have evolved to expand their capabilities and to allow information sharing across different data links. This has in turn led to the dominance of Link 16 for Joint Operations. However despite the plethora of very capable systems, there are still limitations and does not take away the need for experts within the command structure who understand the limitations of the C4I TDL infrastructure. Therefore the need for careful management of the TDL infrastructure is key. ROLE OF DATA LINKS WITHIN C4I Tactical Data Links (TDLs) support the continuing requirement to exchange data within Command, Control, Communications, Computers and Intelligence (C4I) systems; they exist to support Command and Control (C2), Intelligence, Surveillance and Reconnaissance (ISR) functionality. They should be seamless, transparent exchanges of data with the primary C4I or other systems used by each platform. C4I infrastructures are necessarily complex as shown in the figure below which maps out the TDLs that are being used by assets in current battlespace arenas. These TDLs have architectures and require careful management. An appropriate organisation is required to carry out these tasks and a Joint Data Link Operations Centre (JDLOC) or Joint Interface Control Officers Cell (JICC) is as the diagram shows, ideally suited to execute these responsibilities. The diagram shows the intricate paths TDLs take and how joint the battlespace is in reality. Page 1

Tactical Data Links in C4I TDLs have, at least to some extent, been stove-piped; the evolution of the standards and technologies were developed often around platform specific needs, for example, Link 11 is predominantly used for maritime applications (long range, low data rates) whilst Link 16 is based around air operations (high data rates, short range, high speed). The demand for TDLs to provide information exchange across an entire spectrum and geographical area of operations is as high as ever. Many platforms from Air, Maritime, Land and HQs now require relevant data from legacy and future TDLs over secure gateways using recognised secure protocols. To meet these interoperability needs across land and sea, the TDLs standards have evolved and modern Commanders are greeted with a wide range of systems, standards and technologies that can be used to create a fully interoperable architecture. As an example, within the Link 16 TDL, the Joint Range Extension Application Protocol (JREAP) has been created to allow Link 16 networks to have access to data from outside the immediate area. For the Joint Task Force Commander (JTFC) to fully understand his battlespace, a data link validated operating picture is essential. Today Link 16 data received from assets within operational networks as well as other sources such as Intelligence, Meteorology, EW and Imagery results in a Joint Operating Picture (JOP). This is a combination of the Recognised Air Picture (RAP), Recognised Land Picture (RLP) and Recognised Maritime Picture (RMP) contributing to Combat ID and enables the JTFC to make effective measured decisions from multiple sourced C4 architectures. Page 2

INTEROPERABILITY ISSUES AND SOLUTIONS However, several factors may affect and limit interoperability in operations. Landline or microwave bearers have been used for legacy TDLs, but a suitable telecommunications infrastructure must either already exist or be created. Traditional, radio frequency bearers will have advantages and limitations for their operating bands; Link 16 uses UHF and has a limitation of line-of-site. HF will suffer from interference and ionospheric effects. SATCOM bearers will be subject to satellite field of view and channel availability, it is commonly known this will only have a marginal effect on the TDL Operations; it is actual satellite availability that can be the concern. Gateways are secure and reliable when establishing and maintaining connectivity amongst Link participants. Platforms have often arrived in a theatre of operations with only limited data link capability. This raises the issue of data forwarding. This is the process of receiving data on one data link and out putting the data in the proper format and protocol of another data link. The forwarding units of each link will be detailed on the OPTASK Link. To enable platforms without Link 16 to exchange information, Data Forwarding platforms need to be employed. Data forwarding is the process of receiving data on one Data Link and the outputting the data in the proper format and protocol. During the process information is translated from one message format to another. E.g. Link 16 J -Message format to Link 11 M - Message format. Page 3

Where data forwarding capable units are not available, Concurrent Interface Units (CIU) may be employed. CIUs allow tactical data from common sources such as a platforms own sensors and mission systems to be transmitted to different networks simultaneously. CIUs do not data forward but allow data to be transmitted on two different networks from a common source. Link 16 has become the most prominent data link because of the employment of gateways, protocols and SATCOM. This has complimented the traditional RF Link 16 and provided additional redundancy. Therefore the location of participants in large land mass nations such as US, Canada, Australia or mountainous terrain nations has been largely overcome, although challenges still remain. Link 16 possesses the capacity, speed and resilience to enable timely exploitation of tactical data essential to achieving mission aims in an evolving tactical situation. Specifically, the capability makes Link 16 a critical enabler and force multiplier for Battlespace Management (BM), Shared Situation Awareness (SSA) and the wider C2 functions. Data Link authorities embedded within Combined Air Operations Centres, Air Operations Centres and Ground HQs especially the JICCs pro-actively manages the wider C4 architectures through gateways and protocols. European DLOCs presently only manage the integrated C2 architectures within their own infrastructures. The management of C4 architectures primarily manipulates TDL data; although Link 16 data is the primary tactical link that supports the total force mission objective in major national, NATO and Coalition operations. The emphasis for JTFC s for the future is to move away from stove-piped solutions to network enabled solutions that successfully deliver the correct operational data to the correct user quickly, accurately and in an effective efficient manner. The future battlespace is already being shaped whereby gateways will move away from legacy TDLs (Link 1 and Link 11) and employ the use of TDLs such as Link 16, VMF, Link 22 and also ISTAR Data Links. Nations experienced in Link 16 only need secure SA layers of Link 22 and VMF. New nations initially may only be able to afford early entry basic MOTS/COTS software with a light training burden to enable them to have access to Link 22 and VMF data. VMF is procedurally managed by data link authorities presently, whether direct management of this link and others takes place, only time will tell The significant increase in ISTAR data links such as Common Data Link (CDL) and High Integrity Data Link (HIDL) has been aimed at providing a family of interoperable secure data links for use with manned and unmanned aerial vehicles (UAV). The proven advantages of UAV has been evident in recent operations in the remote regions of Afghanistan where the passing of radar, imagery, video and other sensor information to ground stations has been identified as a smart way of gaining intelligence on enemy activity in order to prosecute mission objectives. The heavy bandwidth usage of HIDL and CDL is challenging but the intelligent introduction of flexible gateways and routers could overcome these challenges. Page 4

Watchkeeper uses ISTAR Data Links In the battlespace environment today it is important for TDLs to be successfully implemented through C4 architectures. TDL Network Managers whilst tactically managing and monitoring TDLs such as Link 16, additionally need to closely monitor and manipulate the C4 connectivity architectures through secure gateways. This results in accurate data from other data links reaching the Commander in a timely manner. There are processes that accommodate this such as being able to split connectivity between platforms via multiple data links (e.g use Network Management Systems connectivity displays could be used to display communications architectures). Systems could have planning and monitoring functionality that show communications paths of the forwarding of TDL data to participants. Network Managers, supported by robust procedures can analyse and respond to weaknesses in communication networks. Their assessment of unserviceable radio hardware on platforms or in HQs will avoid broken architectures. The monitoring will enable the efficient management and smarter use of comms paths, back-up hardware and software. This will only be achievable if the adherence to recognised standards is agreed and that software releases are compatible to support the successful exchange of operational data. The future requires a system of systems where by the management and monitoring of theatre communications architectures (protocols, radios and gateways) compliments the tactical management and monitoring of TDL data already established in DLOCS and JICCS. The specialised personnel could become C4I/TDL Network Managers having a complete overview of the comms architectures and tactical networks in the battlespace that adhere to correct standards and a remit to control them. CONCLUSION The paper sets out to explain the challenges and complex requirements that are needed to incorporate TDLs, specifically Link 16 into C4 environments supported by communication architectures. It is important that C4 architectures are robust and interoperable with each other. The present and future roles of data link authorities to manage communications architectures and TDL networks will be refined in the future. The future could be Multi TDL and Communication Management and Monitoring systems enabling DLOCS and JICCs to control, manipulate and monitor complete architectural backbones that ensure TDL operational networks users can exchange data as required. Page 5