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EMULATION OF RADIO ACCESS TECHNOLOGIES FOR RAILWAY COMMUNICATIONS

Periodic Reporting for period 1 - EMULRADIO4RAIL (EMULATION OF RADIO ACCESS TECHNOLOGIES FOR RAILWAY COMMUNICATIONS)

Reporting period: 2018-12-01 to 2019-08-31

EMULRADIO4RAIL (EMULation of RADIO access technologies for RAILway) project will provide an original testing and evaluation platform combinng hardware and software. It will connect directly the real radio access equipment to be tested, the radio channel emulators (physical systems), the Network emulator and the network simulators to mimic Railway network. Initially, we planned to support multiple emulation instances (GSM-R, LTE, Wi-Fi/802.11 5G and SatCom). After discussion with X2RAIL-3 WP3 partners, GSM-R was excluded because industrial partners do not consider it in the Adaptative Communication System (ACS) in development. ACS will replace GSM-R. In addition, as 5G technology is still in development, the solution chosen to emulate 5G system (Open Air Interface-OAI) does not guaranty today the availability of all the 5G NR features. Nevertheless, the methodology developed for LTE using OAI will be transposable to OAI 5G NR as well as OAI 5G Core, with basic software updates, when available.
The project will directly contribute to the development and testing activities for the adaptable communication system for all railway technology demonstrators as defined in the Shif2rail MAAP (TD2.1) in IP2. It will contribute to the cost reduction targeted by the TD2.6 “zero on-site” testing activities. This will reduce time-to-market for RAT for Railways and contribute to greener testing solution by avoiding field trials.
The overall EMULRADIO4RAIL concept is translated into 5 specific project objectives that are addressed in the project work packages.
• Obj1: Applications requirements and railway scenarios for the foreseen RATs
• Obj2: Radio access emulation solutions and radio access emulation tool design, implementation and validation
• Obj3: Assessment of communication capabilities and modelling of IP impairments
• Obj4: Support for integration of the radio access emulation tool in the verification labs of the S2R members
• Obj5: Contribution to Shift2Rail tests strategy
Based on the preliminary specifications and key performance indicators of the applications coming from X2RAIL-1, NGTC and FMRCS, the EMULRADIO4RAIL project has analyzed the different communication characteristics perceivable by the applications and services. The work is summarized in Deliverable D 1.1.

A literature survey of possible interferences that can affect the communications was conducted. The main representative ones have been selected for MS2. Possible volunteer interferences such as electromagnetic attacks are taken into account. The methodology for implementation in the channel emulators is also proposed. MS2 document has been discussed with X2RAIL-3 WP3 partners.

Based on a large literature study, the consortium has investigated existing radio channel models. A first set has been selected and synthetized in MS3 document. These channels models were chosen accordingly to the characteristics of the physical layer emulator, and also to the specific details of the railway-related environments (hilly terrain, tunnel, cuttings, viaducts and rural scenarios). MS3 document has been discussed with X2RAIL-3 WP3 partners.

The project has identified of possible technical solutions for the emulation of the radio access technologies (RAT). This is in addition to the corresponding development of models for IP impairments taking into account the different railway environment scenarios. We have considered the following radio access technologies: Wi-Fi, LTE, LTE-Advanced, Wi-Fi/802.11 SatCom. D2.1 describes the proposed radio emulation tool architecture at high-level. It defines the different modules that will make it up and the way they will be connected.

IP impairments models versus various railways scenarios will be both based on theoretical models, simulations and experimental data obtained in Task 3.2 of WP3 with the platforms. Due to difficulties in physically emulating the satellite radio link in Task 3.2 of WP3, the corresponding modeling of IP impairments will be based on a theoretical/simulated approach over realistic propagation scenarios. We expect to deliver statistical models for key parameters at IP level such as End-to-End delay, jitter, packet loss, packet error, bandwidth, etc. It is important to guaranty the statistical representativity of the experimental assessment.

The objectives of WP3 during the reporting period 1 were: (1) to develop and implement the different building blocks of the radio access emulation tool; (2) to validate the tool with the experimental assessments of the IP parameters in different railway radio channels, corresponding to different environments and interferences identified in WP1. The work is quite finished. The different bricks are ready in the partner labs and we need to plan integration before the end of the year. The modules are for the terrestrial RAT: channel emulators, Open Air Interface Platform, Riverbed module for the backhaul. The satellite emulator subsystem is IP native and it can emulate the performance of existing end-to-end satellite network. The experimental assessment has started. The integration with the prototypes developed in X2RAIL-3 WP3 has not yet started.

The project Website has been open. A first leaflet has been prepared for distribution in different congress and was distributed at WCRR2019. A paper describing the project has been presented at Nets4cars/nets4trains/Nets4aircraft workshop in Colmart in May 2019 with a paper published in LNCS series. A poster describing the main platforms in preparation has been presented at SmartRacon workshop in Lille in June 2019 and in WCRR2019 on Ifsttar booth in front of Shift2rail booth. A paper has been submitted to Eucap 2020 and one at TRA2020. The WP4 progress is in line with what was planned. Data Management Plan (D4.1) and the Dissemination plan (D4.2) have been submitted.

Four F2F meetings were organized and several phone meetings for progress monitoring. Each WP leader has also organized phone meetings wh
Two states of the art on existing representative electromagnetic perturbations for wireless communications and on existing radio channel models in the Railway environment has been performed. Two set of perturbations and radio channel models was chosen and will be implemented in the channel emulators. The novelties proposed in EMULRADIO4RAIL are first to consider coupling between RIVERBED Modeler and Open Air Interface (OAI) instead of considering classical Network Emulator, second to connect channel emulators to OAI platform. The test bed can offer a full-stack (from physical layer to IP level) test environment for Shift2Rail customers.

The expected results before the end of the year 2019 will be:
- Implementation of several radio channel model + perturbations in the channel emulators available in the project.
- Connection of the channel emulators to LTE and WI-Fi equipment to test the methodology proposed for “experimental assessment of IP impairments”
Results expected at the latest in January-February 2020
- Connection of the channel emulators to the OAI interface platform (DTU and IFSTTAR)
- Connection of Riverbed module to OAI (DTU and IFSTTAR)
- Proposal of preliminary IP models as results of the experimental assessment.

The expected impacts remain the same than those highlighted in the DOW.
IKL set up
ULille Test bed
DTU set up