The aim of SP2 is to provide the list of system requirements and constraints to be considered within the project as well as to integrate the other SP outputs and define an overall system architecture supporting the IPS network solution, the IMR (including the new AeroWiMAX airport link) and integrated antenna solution. The requirements definition will be largely based on existing work from previous projects but will have to take into account more recent advances in communication technologies, integrate and consolidate the detailed requirements coming from the different SP (SP3, SP4, SP5, SP6). The system architecture will be defined in several steps allowing concentrating the activity at the re-quired time and to capturing the progress of SP3-6. The system usage and operational aspects will be defined during the first activity period. Then, global system architecture will be defined in the second activity period based in particular on the preliminary network architecture from WP3.2. Finally, the sys-tem architeture will be consolidated based in particular on the final version of the network architecture from WP3.2. The main outputs of SP2 will be:

• Consolidated set of requirements as well as a list of constraints (regulatory, certification, opera-tional) and scenarios that will serve as framework for the rest of the project
• Reference system architecture and implementation approach of the network solutions proposed in SP3 in the different entities (on-board and on the ground).

The main objective of SP3 is the specification of a Service Oriented Architecture (SOA) and networking solutions allowing integration and interoperability at different levels, with IPv6 as unification point: interworking of different data link technologies (ground-based, satellite-based, airport systems as main streamline for validation, air-to-air MANET as long term extension), interoperability of network and transport technologies (ACARS, ATN/OSI, IPv4, IPv6 networks), and integration of operational domains (ATS, AOC/AAC, APC).

The main outputs of SP3 will be:

• Consolidation and derivation of detailed network requirements and detailed network architecture including solutions for network interoperability based on the system description from SP2.
• Middleware specification as common interface to applications for service integration.
• Specification of global security concept
• Specification of the integrated IPS network, including solutions for network management, resource management, mobility management and IPv6 naming and addressing.
• Integration approach of future aeronautical MANETs into the SANDRA system.
• IPS network design validation and performance assessment by means of simulation.

Router prototypes implementing the specified networking solutions and interfaces will be developed and tested for overall integration in the SANDRA test-bed in SP7. Middleware solutions will be partially implemented. DLR has lead of SP3 and partners involved in SP3 activities are: SCOM, DLR, SSI, TAS, THAV, AATN, UniBRAD, DASSAV, DFS, INRIA, SITA, SLOT, TGS, USBG.

SP4 will design and test a prototype IMR system capable of interfacing with sufficient bearers to prove all of the concepts derived and developed in the SANDRA communications system. The IMR will be integrated in the overall SANDRA test-bed in SP7. The top priorities of this development will be to demonstrate the ability to:

• Reconfigure automatically in the event of failure of any of its constituent elements to give priority to the preservation of the highest criticality links currently in operation. This will require some management of the protocol stacks across the IMRs to maintain some harmonization of their statuses. Transparent fault tolerance of the SANDRA communications system will be validated in SP7.
• Seamlessly transfer between the bearers. From the list of prototype bearers that will be implemented in SANDRA, it can be seen that there is one bearer for each airspace type. A simulation will be made of a flight between these airspaces, and the SANDRA communications system will be shown to transfer between the respective airspace bearers in a seamless fashion.

The steps taken in SP4 to achieve these objectives are:

• Synthesize the architecture of the IMR.
• Identify the implications and advantages of the SANDRA communications system on future aircrafts’ avionics architectures.
• Establish and design link resource management functions.
• Identify and design the interfaces between the IMR building blocks.
• Establish processing requirements and specify a COTS processing platform and RTOS for use by the SANDRA IMR
• Implement the IMR for the 4 bearers and the resource management functionality
• Integrate and test the IMR sub-systems.
• Analyze the results of the programme and propose a definitive IMR solution for civil aircraft standardization.

The primary objective of SP5 will be to design and develop a prototype phased array antenna to receive and transmit L-band SBB Satcom and to receive Ku band DVB Satcom. The antenna will be integrated and validated in SP7 to prove the overall SANDRA system concept. The work to achieve this objective in SP5 is as follows:

• Consolidation of the requirements for the integrated antenna.
• Definition of the overall antenna package’s form fit and function. Electrical interfaces to the aircraft are expected to conform to existing standards, but if new interfaces are required, they will be developed here and delivered to other SPs as required. Synthesis of the phased array geometry of patches and radiating elements, the layout and multiplexing of the element feeds, and the technology and architecture of the beam forming phase shifters.
• Derivation of the detailed requirements for the optical beam forming (OBFS) system and for detailed design of the Triplex based optical beam forming chip.
• Detailed design of the optical beam forming sub-system and controller, including the interfacing with the aircraft.
• Perform a feasibility study on the use of MMIC technology for beam forming as an alternative to the OBFN.
• Fabrication of the OBFN chip and its packaging, and characterization of its performance.
• Design, development, and fabrication of an electro absorption modulator array for incorporation in the OBFN.
• Integration of the complete OBFN system.
• Manufacture of the complete prototype antenna.
• Testing, validation, and certification of the complete antenna system.

The main objective of SP6 is the design of an aeronautical standard based on IEEE 802.16e (WiMAX) and using the MLS sub-band for airport surface operations, following the Future Communications Study technology assessment recommendations and taking into account the possibility of inputs to WRC 2011. Dedicated WiMAX trials will be done in a realistic airport environment in SP6, the airborne WiMAX sub-system will be integrated in the IMR in SP4, and the overall WiMAX system will be integrated in SP7. Main outputs of SP6 will be:

• requirement analysis and high level system design with strong contribution from all the users (WP6.1);
• development of the new profile description, validation by means of simulation (WP6.2);
• deployment approach addressing the aircraft platform and the ground system planning issues (RF planning, capacity planning, antennae issues, interference. problems), development of a collaborative view on industrial exploitation of the AeroWiMAX (WP6.3);
• development of prototype AeroWiMAX airborne and ground subsystems in strong collaboration with WP4.3.3 (IMR AeroWiMAX module) for validation of the sub-systems in dedicated trials in a realistic airport environment and for overall integration in the SANDRA test-bed in SP7 (WP6.4/WP6.5).

An overall test-bed for validation purpose of the overall SANDRA concept and architecture will be implemented. SP7 test-bed integrates the results from other SPs, especially SP3, SP4, SP5, and SP6. On-ground and in-flight trials are used to show and prove the integrated SANDRA approach and its benefits with respect to existing aeronautical communications systems based on single radio technologies, thus incapable to overcome limitations of individual radio access systems, e.g. limited coverage of direct A/G data links, high delay of satellite systems, etc. The validation activity in SP7 will be organised as follows:

• Definition and planning of validation activities.
• Selection and implementation of representative applications for the validation activities.
• Integration of the sub-systems (airborne and ground components) individually developed and fully tested within the other SPs: router prototypes, IMR, integrated antenna, Aeron-BGAN, Ku-Band and WiMAX ground systems, OSI/VDL2 legacy sub-system, applications
• Validation of the SANDRA concept through overall test-bed in on-ground and in-flight trials.

DLR has lead of SP7 and partners involved in SP7 activities are: SCOM, TAS, TAUK, THAV, TRT, AATN, UniBRAD, DASSAV, DFS, INCS, E&Y, MONS, SITA, TGS, USBG.

First aim of SP8 is to make sure that the project approach and findings will be transferable to a real world system. SANDRA recognizes the existence of higher level initiatives like SESAR, so SANDRA approach will be to:

• Investigate in a collaborative manner some key themes from FCS to speed up Standardization and adoption
• Develop transition and exploitation concepts integrated with SESAR approach
• Directly contribute technological results and preparatory work envisaging standardization and exploitation effort being finalized in SESAR.