Workstream 1 (WP2). Obj. 1.1 have been covered in D2.1. The deliverable provided an overview of the prior state-of-art in the areas of selected ABs, of interest for improving capabilities of the Adaptable Communication System (ACS). A set of candidate communication technologies are investigated as potential ones for railway applications. The methodology is based on the most important communication features not only from a technological perspective (i.e. standard, protocol, security, and performance) but also considering (but not limited to) other factors as maturity, ease of development and deployment costs, together with economic and business implications.
Obj. 1.2 and Obj. 1.3 have been covered in D2.2 and D2.3. Deliverable D2.2 assessed the selected AB, rejecting some technologies (e.g. short range IoT and those not mature) because they are not suitable for the scenarios and traffic service classes of ACS. The following technologies have been selected as eligible from this analysis: Free Space Optics (FSO), High-Altitude Platform System (HAPS) and Low-Earth Orbit satellites (LEO). In D2.3 the economic analysis and business plan for deployment have been presented for all three AB technologies that have passed the technical verification (in D2.2). Also, in D2.3. the performances offered by the selected AB technologies have been compared with those of the TBs. In addition, the integration of AB with TBs in the various railway scenarios (metro, regional, mainline) has been discussed.
The WP2 activities in the second period of the project started with the market scouting of technologies and devices for selected ABs. Due to the unavailability of devices, we considered a simulation-based approach. We have developed three simulation software tools. The results in D2.4 assess the applicability of FSO, LEO, and HAPS as ABs for ACS.
Workstream 2 (WP3). Obj. 2.1 has been covered in D3.1 by reviewing and identifying the appropriate transport and application protocols, while Obj. 2.2 has been covered in D3.2 studying and proposing some strategies for allowing the IPv4 and IPv6 interworking. Obj. 2.3 has been covered by the development of the emulator at IP level, thus providing the emulation/simulation support to investigate the transport and application protocols. The emulator development and related tests have been described within the D3.3.
Obj. 2.4 has been partially covered in task 3.4 (M9-M13). In particular, the corresponding deliverable D3.4 (M13) covers the analysis of the transport protocols for services such as constant bit rate, variable bit rate and file transfer. Cases on transport protocol coexistence is also considered. The rest of Obj. 2.4 (i.e. analysis related to the application protocols) will be covered in the next period.
The WP3 activities in the second period of the project have continued and concluded the activities of Obj. 2.4. In particular we started with the analysis of options for transport and application protocols planned in Task 3.6 concerning the analysis of secure versions of the transport and application layer protocols.
The analysis concerned the secure versions of the TCP with the novel QUIC protocol. The HTTP and FTP and their secure versions have been also analyzed. Protocol performances were assessed using the emulator developed in Task 3.3 (D3.3). We observed that the TCP BBR and QUIC protocols offer better performance and are resistant to packet loss. Finally, we analyzed the security aspects of the considered transport and application protocols. We observed that the robustness against the threats in Table 5 in D3.3 of the application protocols is related to the secure features of the underlying transport protocol. All results are reported in deliverable D3.5.
