Satcom for Railway Communications - Benefits in a Bearer Flexible Scenario

Transcription

1 Satcom for Railway Communications - Benefits in a Bearer Flexible Scenario ETSI Workshop "Developing the Future Radio for Rail Transport 4-5 July 2018, Sophia Antipolis - France 1

2 Table of Contents Brief introduction to Satellite Communications (SatCom) SatCom as a complement of terrestrial systems in a multi-technology environment SatCom challenges in the railway environment Recall of ERA Study outcomes - Key messages from the ERA Study Final Report Current projects: Iris for Railway Communications Conclusions 2

3 Introduction to Satellite Systems Orbit Types Medium Earth Orbit (MEO) Altitude: km Low Earth Orbit (LEO) Altitude: km Geostationary Orbit (GEO) Altitude: km Highly Elliptical Orbit (HEO) 3

4 Introduction to Satellite Systems: Coverage Types Key Design Parameters: - Type of coverage (system designer) depending on the requested service area (customer) - Spot beams dimensions => gain and frequency re-use - Satellite antenna dimensions and typologies vs performance and accommodation platform and launcher - Type of orbits 4

5 Introduction to Satellite Systems Typical SatCom System Architecture Space Segment Mobile Links Fixed Links Feeder Links TT&C Links Inter-satellite Links Fixed Terminal User Segment Mobile/Portable Terminal SCC Ground Segment NCC NMC Operator Segment GW Terrestrial Core Networks GW: Gateway MS: Management Station NCC: Network Control Centre NMC: Network Management Centre SCC: Satellite Control Centre 5

6 Introduction to Satellite Systems: Frequency Bands 6

7 Benefits of SatCom Main benefits Global connectivity: anywhere, anytime Costs are distance insensitive Service to mobile users Wideband capability to support High Speed Data and Digital Services Freedom from natural barriers (island, mountains, deserts) Better coverage of rural and underdeveloped areas Easy service deployment Highly reliable and predictable 7

8 8 Recent Thales Alenia Space heritage on LEO & GEO Satellites - State of art Satellite <reference> Launch Date SICRAL 1 07 Feb ATLANTIC BIRD 1 28 Aug COSMO-SkyMed 07 June 2007 COSMO-SkyMed-2 08 December 2007 RADARSAT-2 14 December 2007 COSMO-SkyMed-3 23 October 2008 SICRAL 1B 20 Apr COSMO-SkyMed-4 6 November 2010 ATHENA FIDUS 26 Feb SENTINEL-1A 03 April 2014 SICRAL 2 26 Apr SENTINEL-1B 22 April 2016 SENTINEL-3A 16 February 2016 SENTINEL-3B 2018 SENTINEL-3C 2021 SENTINEL-3D 2022 COSMO 2 nd Gen PFM Q1/2018 COSMO 2 nd Gen FM2 Q1/2019 SENTINEL-1C 2021 SENTINEL-1D 2021 Mirror 05/04/2018 GovSatCom 2022 SICRAL COSMO-SkyMed ATLANTIC BIRD 1 SICRAL 1 8 RADARSAT-2 SENTINEL-1 SENTINEL-3 SICRAL 1B SICRAL 2 ATHENA FIDUS

9 SatCom Systems: examples of existing and planned 9

10 Mobile and Portable SatCom Terminals Mobile and portable SatCom Terminal types Handheld: mobile Personal: portable (briefcase, laptop, palmtop) Vehicular: mobile (car, train, ships, aircrafts etc.) Key Design Parameters: - Compactness - Light weight - Mechanical strength - Easy installation - Radiation - Ability to track the satellite Satellite Tracking for Mobile and Portable SatCom Terminals Satellite tracking depends on the terminal antenna features (directive or omnidirectional) Tracking functions need Beam steering Mechanical Electronic 10

11 SatCom as a complement of terrestrial systems in a multi-technology environment SatCom, FRMCS and 5G SatCom in the FRMCS architecture SatCom is considered in FRMCS as another RAN The overall objective is that SatCom is entirely transparent to the user, who perceives an increased coverage and availability Towards 5G SatCom currently considered as a purely non-3gpp RAN SatCom foreseen to converge as part of 5G according to 3GPP TS QoS has to be ensured in order to achieve the expected End-to-End performances 11

12 SatCom challenges in the railway environment Technological challenges (1/3) Availability Challenges Coverage gaps due to tunnels, mountains, etc. Higher frequency bands (Ku, Ka) provide more bandwidth but signal is degraded with weather (e.g. rain). Lower frequencies (L band) more robust (better for safety applications) but have less bandwidth. Periodic signal degradations due to obstruction by the railway infrastructure (e.g. posts, catenary, etc.) Solutions Gap fillers resend information from the satellite to an area without satellite visibility (and vice-versa) In a multi-technology environment, gaps can also be covered by terrestrial technologies More robust waveforms for mobile SatCom in challenging environments 12

13 SatCom challenges in the railway environment Technological challenges (2/3) Latency Challenges Railway Critical applications (e.g. ETCS and also voice-related applications) require a relatively short delay Solutions Eventual revision of latency requirements in certain areas (i.e. remote/rural for railway) Geostationary satellites have a longer round-trip delay with respect to terrestrial systems due to their distance Double hop (terminal 1 sat hub sat terminal 2) may be required in some configurations, adding more delay 13

14 SatCom challenges in the railway environment Technological challenges (3/3) Terminal Size, Weight and Power (SWaP) Challenges Solutions Lower frequencies Higher frequencies Railway voice services imply the use of a handheld terminal. That imposes: stringent limitations in terms of reachable bandwidth constraints in the frequency band of operation Performance for handhelds to be analysed more in detail but will depend on the satellite constellation type and used frequency band Handhelds, even with GEO satellites, are possible for low data rate services but they are not meeting the current availability requirements Consider SatCom mostly for only safety data (e.g. ETCS) applications Consider use of a wifi terminal connected to the local train network, which then uses the appropriate bearer. Outside the train, either cellular communications or wifi terminal connected to a flyaway satcomequipped vehicle. Note: Higher frequency bands are more suitable for performance and business applications 14

15 ERA study of SatCom Recall of ERA Study outcomes Key messages from the ERA Study Final Report 2017 ERA Study on feasibility of SatCom for railway communication 11 different satcom systems analysed including different orbits, commercial and potential systems The most demanding criteria for SatCom solutions are: availability, latency and handhelds There is no SatCom solution (i.e. neither deployed nor planned) meeting all the simultaneous criteria for railway safety applications (i.e. critical) Narrow band Satcom are good candidates for satisfying the safety DATA applications (i.e. ETCS) Out of the existing/planned systems, Iris FOC is the best positioned to meet the criteria list for critical applications 15

16 ERA study of SatCom Recall of ERA Study recommendations Recommendations Follow the same approach as in the aeronautical environment, where performance requirements depend on the airspace domain (e.g. airport vs. remote oceanic) Stringent requirements for airports with mandatory multilink; more relaxed for oceanic with only satellite Consider the possibility to use SatCom to provide only ETCS data (i.e. not considering voice services) or keep also voice but only for regional lines and/or remote areas Continue research: railway traffic estimation, analyse the Iris system (used for Air Traffic Management), etc. 16

17 Current projects: Iris for Railway Communications Main objectives The aim is to perform a feasibility assessment of the Iris SatCom solution, specifically defined for the aeronautics domain, in the railway operational scenario Identified Key Objectives 1. To assess the suitability of the Iris service provision concept for the aeronautics domain in the railway domain, highlighting differences and complementarities 2. To identify voice and data railway applications supported simultaneously by SATCOM solution according to railway safety critical applications requirements 3. To develop a railway traffic dimensioning tool to allow the estimation of communication traffic for a specific region 4. To identify the technical requirements and system architecture of a SATCOM based solution (space, ground and user segment) 5. Provide a roadmap of development and testing in line with ERA program and taking into account the necessary homologation/certification steps Start date of the Study: April 2018 End date of the Study: January

18 Iris Program: some highlights ESA ARTES program aiming to supply a validated satellite-based communication solution for the European Air Traffic Management (ATM) System Part of a broader push to modernise air traffic management in close collaboration with the SESAR Joint Undertaking launched in 2006 by EUROCONTROL and the European Union Iris will complement existing and planned systems, supporting the growth of air traffic Deployment and certification of the Iris Initial Operation Capability in 2019 Satcom for ATM over European Continental Area Design and Development of Iris Full Operation Capability worldwide service in 2028 Iris will enable 4D trajectory management via satellite, for both continental and oceanic airspaces, as a safe, reliable and secure service Robust data links to be used by the vast majority of aircraft, complemented with conventional voice communications between pilots and controllers The space component is part of a much larger system, tuned to the needs of external partners and endusers who are not always familiar with satellite technology Inmarsat is the Iris Prime and the Iris Service provider TAS Italia is Iris Core Team member, Space Segment Prime and System Design contributor TAS Italia and INDRA are actively contributing to SatCom for ATM definition in EC/SESAR 18

19 Main topics for Iris applicability in Railway Communications Iris for ATM Radio resources: dual link, multilink Different CoS (Class of Service) and QoS (Quality of Service) Constraints for SatCom terminal accommodation/integration with other equipment Complementation of existing networks with Satcom for improving availability and capacity Under evaluation for applicability to Rail environment in Iris for Rail Communications Constraints on costs Safety of Life (SoL) certification Evolution towards IP protocol Communications + Navigation integration 19

20 Iris for Railway Communications Main Activities and Work Logic Solution Design System Requirements Satcom Criteria for Railway Technical requirements for FRMCS Iris Design Suitability Analysis for Rail Architecture and Operational Scenarios Traffic dimensioning tool Suitability Analysis of the Iris IOC and FOC for the required capacity and coverage (European/World coverage) o SatCom in railway propagation channel, QoS, Handover, Multi Access Core Network MACN Gaps and issues Roadmap Viability Analysis Suitability of Iris service provisioning for Rail Approach for OPEX and CAPEX estimate Liaison with Standardisation Groups 20

21 Conclusions This presentation has provided highlights on Satellite Communications main concepts SatCom as a complement of terrestrial systems in a multi-technology environment SatCom challenges in the railway environment ERA Study outcomes and recommendations Current projects: Iris for Railway Communications The Iris for Railway Communications study will provide Assessment of the required SatCom capacity for railway critical safety communications Assessment of Iris Satcom solution capacity of meeting all the simultaneous criteria for railway safety applications Possible solutions for the integration between satcom and terrestrial solutions in a Multi Access Core Network (MACN) Possible solutions for exploiting SatCom in railway environment The Iris System is candidate solution to complement existing and planned terrestrial communication system for rail Recent and ongoing studies (ERA and ESA Iris for Railway Communications) represent a significant step to this aim 21