TETRA in Railway Communications and Signalling

TETRA – Digital wireless evolution in Railway Communications & Signalling; local and global insights to Rail, Metro and Light Rail
(November 2017)

This paper has been prepared with input from main contributors of The Critical Communication Association TCCA, the Critical Communications Broadband group UK and members of the Australasian TETRA & Critical Communications Forum ATCCF .

Introduction
Modern rail transportation is a vital pillar for driving the economic development of cities and nations. Linking increasingly complex supply chains through corridors of commerce and managing the reliability, safety and security of millions of journeys, while simultaneously delivering a personalized experience for each individual and the timely delivery of every freight.
With increasing automation and integration of public and private rail, metro, light rail, short and long haul freight services, the need for secure, mission-critical digital communication technologies has never been more important in ensuring efficient, un-interrupted, safe and secure rail operations supporting critical person-to-person, person-to-machine, and machine-to-machine information exchanges.

There are Complex Business Drivers that includes change/migration/technology selection for ageing infrastructure and technology obsolescence, improving line capacity and modernization programs that include New Greenfield transportation projects and the integrations with existing services
Service Delivery Demands (Concession KPI’s)
 Radio Spectrum reforms/availability
 Regulatory/ Safety Compliance
 Business Efficiency/ROI (Opex- Capex)
 Outsourced operation/ maintenance /service delivery/ financing
 Unified Communications Solutions
 Intermodal considerations (public and private rail/freight services)
 Accommodation of legacy operations

The challenge
Operators, globally, are facing network replacement through obsolescence, infrastructure renewal or expansion.
Business and operational demands are dictating enhanced and secure voice and data capabilities in ensuring un-interrupted transport operations and integrated customer information services.

It is clear that the use of IT and digital communications throughout the transportation industry is becoming ever more complex with operators seriously reviewing, considering and protecting their end-to-end systems to ensure that they are reliable, available and not vulnerable to interference, breach of security and cyberattacks.
Reliability, safety and security of passenger and freight travel must be guaranteed while reaching new heights of service, productivity, and profitability.

Digital Telecommunication Technologies (Voice & Signalling)
Central to delivering on the promise of Intelligent Rail Transportation Solutions is a single, converged TETRA Rail communications architecture solution that is capable of supporting the full array of mission critical and business critical rail communications requirements.

a. TETRA Solution
The latest releases of the multi-vendor ETSI, developed and supported TETRA Voice + Data wireless technology offers a wide range of transport services that include voice, SDS, packet data and circuit data – boosted by embedded services at the transport layer that allows for efficient AVL, voice and data applications and railway signalling applications such as ERMTS, CBTC and PTC.
TETRA digital rail networks will mobilize intelligence and deliver real-time situational awareness across stations, railway lines, railway carriages and operational control centers by utilizing a state-of-the-art, critical voice and converged IP data transport network that serves the entirety of rail operations.

TETRA Rail applications are a suitable alternative to support the wireless data requirements demanded by the signalling applications such as ECTS, CBTC or others. Railway signalling via TETRA provides a continuous data transmission (On-board < > Wayside Equipment), high availability and reliability, line capacity optimization and reduced number of wayside equipment.

Globally TETRA has emerged as most used radio standard for transportation providing efficient and cost effective communications that meets service availability and safety expectations as TETRA (5.0) provide following functionalities:
Voice services with driver, passengers (PA), security and maintenance personnel and the ability to integrate with external communications networks e.g. Police and Public Safety for which the Mission Critical standardisation is progressing through organisations such as the 3GPP, ETSI and the support of the TETRA and Critical Communications Association.
Non-critical data for on-line video surveillance, for applications to increase security and safety in rail vehicles and passenger stations and depots.
Critical data for interconnection with on-board control systems (TCMS), rolling stock monitoring and alarms & event management, vehicle diagnostics, train identity assignment, vehicle location and emergencies, and the integration with passenger information systems (PIS).
Vital data to support railway signalling applications such as ERMTS, CBTC and PTC (8.0) assuring comfort, punctuality, availability, and the security and safety for passengers and freight, managing the driving conditions of the trains.
Cellular based roaming is built into the TETRA Air Interface standard allowing TETRA radios to self-learn of neighbour cell details, enabling seamless and synchronised radio handover when travelling between repeater sites to ensure no drop-outs of voice or signalling.
Secure Authentication ensures all radio devices on the network are truly authorised for secure voice or signalling.
Complimentary Broadband radio access layer to support applications such as:
real-time video to monitor status inside the trains and fixed video surveillance of external items (tunnels, crossings and stations) and file transfer between the train Control Centre and trains/staff.

b. DMR Solution
An alternative to TETRA is the lower tiered DMR digital radio solution.
As a result of the DMR standardization coming from same European standards body ETSI and following the same interoperability regime as TETRA that this digital open standard is enjoying growth opportunities.

DMR compliments TETRA and has some overlapping opportunities dependant on the end user customer requirements.
Importantly it gives customers a broader choice of open standard multivendor products. There are distinctions in functionalities and maturity between TETRA and DMR given that DMR is a more recent published open standard and product innovations and interoperability are still evolving.

c. TETRA and Hybrid LTE Solutions
The role of mission-critical digital communications in transportation must address functionality, reliability, safety and security in any rail and light rail environment.

LTE is a very capable technology for what it was designed to do but very different from what mission critical digital PMR technologies such as open standard TETRA and P25 are designed to do.

For services requiring high-bandwidth solutions to facilitate applications such as video streaming, internet access and advanced mapping a digital TETRA solution can be complimented with LTE data.
Currently a number of vendors provide hybrid solutions that offers both TETRA and LTE.

Meanwhile the LTE mission critical standardization is progressing through organisations such as the Third Generation Partnership Project (3GPP) standardizations group, ETSI and the support of The Critical Communications Association TCCA.
This will lead to the ultimate release of future fully featured mission critical LTE systems.

Evolution
In Europe following the announcement of obsolescence of the current GSM-R technology by the European Railway Agency (ERA) there are moves by railway organisations to migrate communications from GSM-R to lower cost TETRA and private/professional and or possibly commercial LTE networks that provides an entirely new set of options beyond the current GSM-R technology replaced because of age, availability and spectrum issues.

E.g. In Finland, the Finnish Transport Agency made the decision to migrate to TETRA and public mobile networks (commercial LTE) has already been referred to as the “Unified Railway Communication and Application” (URCA).
Continued importance of Standards to Rail operations/interworking
GSM-R is preparing for End Of Life.

LTE/Broadband standardization work for rail and mission critical operations are still incomplete but progressing positively however commercialization and proven rail compliant and hardened solutions will take time.

The ETSI specified TETRA Standard is heavily adopted for railway operations (mature Voice and Data including ETCS capabilities and GSM-R like replacements and rail proven product innovations is continuing with complimentary hybrid broadband solutions emerging from several international suppliers.

Importance of Open Standards
There is no doubt that a proprietary technology solution can be brought to market in less time than a solution conforming to a recognised open standard.
However, large user organisations, especially those in the public sector, have recognised that some proprietary solutions can meet their needs but the ‘tie in’ to a single supplier can have significant disadvantages. All of the foregoing has been clearly proven over many years by the success of ETSI standards such as TETRA, GSM, UMTS and many others.

Risks of proprietary solutions include: Fragmented markets, potentially even negating global standardisation efforts by creating ‘de facto standards, potentially costly and technically risky due to single-source lock-in. Traditionally, LMR/PMR rail providers are gravitating solutions to ETSI open standards such as (TETRA, DMR), IP based and gateway, control, bridging- products and applications with VoIP/RoIP/broadband/bluetooth/Wi-Fi and legacy technologies.

Standards are central to the enabling of the digital evolution & substantiate significant stakeholder investment. As an example TETRA networks can grow cost effectively at the same pace as rail operations expand over time.
GSM-R is facing a number of challenges:

Becoming end of life, with vendor support uncertain beyond 2030 or earlier.
Extra data transmission bandwidth is required in some areas to support railway operations
Rollout of European Rail Traffic Management System (ERTMS) has increased strain on GSM-R networks
Successor technology required by 2020 for trials and by 2022 for commencement of deployment
A rather similar timeline to those of other critical communications users such as Public Protection and Disaster Relief (PPDR) services globally

Meanwhile the International Railway Union (UIC) has published a user requirement specification: “Future Railway Mobile Communication System – FRMCS”. The TETRA and Critical Communications Association (TCCA) and the International Railway Union (UIC) are cooperating in 3GPP and other bodies to pursue the development and adoption of common, global, mobile broadband standards and solutions for users whose operations are mission or business critical includes all current TETRA and GSM-R, etc. PMR/LMR user groups, e.g. PPDR and railways.

The 3GPP WG SA1 has completed an initial study (3GPP S1-161588) which:
a. identified which Future Railway Mobile Communication System (FRMCS) requirements are in the working scope of 3GPP
b. completed a gap analysis against existing functionality in 3GPP Rel-14 defined additional work needed to accommodate FRMCS in 3GPP Rel-15.

The 3GPP group is propelling the trials and deployments of mission critical LTE.
3GPP Releases 13 and 14 (2016/17) introduced enhancements features, such as mission critical push-to-talk (PTT), LTE device-to-device communications and LTE broadcast. Globally LTE solution vendors have started to address the rail market (caveat emptor in advance of standards).

Alternatives to GSM-R.
The TETRA rail solutions in terms of cost, spectrum consumption, functionality and safety are a real economic alternative to GSM-R as it addresses ERMTS requirements.

TETRA has inherent advantages of operating mission digital radio. TERA include better voice quality, fast call set-up time (<500 msec), improved data services (packet data), more efficient radio spectrum and using less infrastructure than GSM-R that delivers lower implementation, operational and maintenance costs. The further advantage is that a digital TETRA solution can be complimented with a Broadband radio access layer (TETRA + LTE hybrid solution) currently available from various vendors. Suggested Implementation & Migration strategies The following issues are becoming established on the continuum for implementation & migration strategies: The U.K, United States, and South Korea will host the world’s first three operational public-safety or mission critical LTE networks early 2018.
Almost certainly implementation of nationwide 4G/5G networks dedicated to critical communications for transport, etc. will prove cost-prohibitive for many authorities.
Adequate and viable spectrum may not be available for dedicated 4/5G services anyway.
Thus commercial MNOs with an interest in the business case for critical services will likely play an increasing part in critical broadband provision for the future, perhaps as part of hybrid public / private networks, spectrum / network assets sharing agreements, and more.
Mission critical users globally including transport continue to invest in or upgrade to new digital narrow & wideband radio technologies such as TETRA (incl. DMR), and P25 (6.1) while alternative “rail proven” broadband standards and products mature.
Currently private/professional LTE solutions are beginning to compliment starting with non-vital broadband data e.g. as part of a hybrid approach combining TETRA and LTE towards a mission critical broadband future.
Rather than to swallow a broadband LTE project whole, some critical radio users are taking it gradually, keeping what is best about their current networks and building incrementally for the broadband future.

Global Experience
Globally TETRA has emerged as one of the most used radio standard for transportation with many successful installations providing efficient digital communications that meets service availability, reliability, and safety expectations for train operations with the flexibility for dynamic optimisation for moving passengers and goods quickly, efficiently and safely that are a daily challenge for rail operators.

Experiences with Metro, Urban and Light Rail systems are now transferred to other rail services around the world including long haul and freight rail services with examples in the Australian resources sector.

TETRA vendors around the globe provide high level of customization of on-board equipment including signalling to adapt to different railway manufacturers and integrators that include driverless trains in both Europe and Asia. (1.5)
Technology adaption in Australia

Examples of the successful adoption of TETRA digital radio solutions in the Transportation sector in Australia include: – – Fortescue Project and Royhill long haul freight rail mining projects that utilize TETRA in Western Australia, and the long distance Aurizon freight rail project in Queensland.
Light Rail services include Sydney NW Rail, Sydney Light Rail and the Gold Coast Light Rail projects that use TETRA solutions.

Conclusion
TETRA’s ability to support railway signalling standards such as ETCS, paves the way for
Australian rail networks to introduce more affordable advanced train communications and control systems with next generation rail communications.

With a state-of-the-art, converged IP data transport network serving the entirety of rail operations and powerful TETRA radio and LTE broadband data connections, users can mobilize intelligence and deliver real-time situational awareness across stations, lines, cars and operational control centers.
Mission critical Long Term Evolution (LTE) will most likely hit the mainstream markets after 2020 as trials and deployments gain momentum across the world.

Many countries will likely follow suit, either through a dedicated public-safety LTE network or a hosted or shared infrastructure model e.g. TETRA + LTE. Coexistence with legacy public-safety protocols is crucial, as legacy protocols, such as TETRA, DMR and Project 25 (P25), are still being deployed by agencies across the world.

Mission critical LTE guarantees features that generate augmented user experience for both public-safety agencies as well as secure and safe railway operations through mission critical push to talk (PTT) voice, LTE device-to-device communications, LTE broadcast, video streaming, file sharing and real-time analytics, without compromising security.

These cutting-edge digital solutions leverage the power of technologies to tackle the daily operational challenges and high long-term capital costs of rail networks moving across the significant distances and urban and light rail networks in Australia towards a mission critical broadband future.

Reference list of Australian TETRA Rail Installations

Fortescue Rail – 280 km heavy rail network from mine to Port Hedland, Western Australia that utilises a voice and data TETRA system along the railway corridor connected via integrated backbone optic fibre transmission system.
Roy Hill Rail Project – 344 km single line, heavy haul railway from mine site to Port Hedland, WA, Pilbara Region. Project utilizes integrated Voice and Data Mobile Radio Services comprising >28 sites to provide extensive wireless coverage along rail corridor from mine to port (350 km). Integrated main backbone and way side backbone transmission systems, Voice + basic Train Control System (TCS) railway signalling. Migrating in future to Driverless Automatic Train Operation (ATO)
Aurizon Qld Freight Rail System (New project under contract)
Light Rail Systems (Australia)
o Gold Coast Light Rail, Australia
o Sydney Light Rail, Australia
o Sydney North West Line, Australia
Collection of International TETRA Rail Installations (random selection)
o London Underground , U.K
o Paris Metro, France SAMPOL
o ETRA – FGV Valenciana railways, Spain
o Mexico D.F. Metro Line 12, Mexico
o Beijing Metro lines, PRC
o Mallorca Metro, Spain
o Mexico D.F. Metro Lines 2 and B, Mexico
o Beijing Capital Airport Express Rail, PRC
o Stockholm Metro, Sweden
o Barcelona Metro Line 9, Spain
o Rio de Janeiro railways, EFACEC, Brazil
o GuangZhou Metro Corp -PRC
o StorStockholms Lokaltrafik, Sweden
o Madrid Metro, – Spain
o Santiago Metro, Lines 4 and 4A, Chile
o Nanjing Metro Corp – PRC
o Helsinki City Transport, Finland
o Bilbao Metro – Spain
o Buenavista-Cuautitlán, Mexico
o Shenzhen Metro – PRC
o Copenhagen Metro, Denmark
o Euskotren – Basque country railways
o Lima Light Train, Perú
o Shenyang Metro – PRC
o Danish State Railways, Denmark
o Tenerife light train, Spain
o North Atlantic Railway FENOCO, Colombia
o Wuhan Metro – PRC
o SNCF -French Railways, France FCC –
o Zaragoza tramway, Spain
o Transporte masivo Metrolinea, Colombia
o Ningqi Railway Company – PRC
o Wuppertal Schwebebahn, Germany
o New Jersey Transit Authority, USA
o Shanghai Metro, PRC
o Bayerische Zugspitzbahn, Germany
o Metro Transportes do Sul Portugal
o Toronto Transit Authority- Canada
o Chengdu Metro, PRC
o Chemnitzer Verkehrsbetriebe, Germany
o Warsaw Metro Line 2, Poland
o MENA Kunming Metro, PRC
o Dresdener Verkehrsbetriebe, Germany
o Metro de Argel, Algeria
o Xian Metro , PRC
o North-Rhine Westphalian Germany
o Oran and Constantine tram, Algeria
o Taiwan High-speed Rail, Taiwan
o Verkehrs AG Nürnberg Germany
o Budapest Metro Line 4 Hungary EFACEC-IKUSI –
o Algeria Daegu Subway, Korea
o Würzburger Straßenbahnen Germany
o Budapest public transport (BKV) Hungary
o Korea Airport Railroad, Korea
o BVG Metro, Germany
o Bergamo Public Bus Transport, Italy
o Mumbai Metro & Monorail, India
o MTRC Metro – HongKong
o T-SYSTEMS – Nuremberg Metro, Germany
o RUSSIAN RAILWAY – Line Moscu – St.Petersburg, Russia
o New Delhi Railway Corp – India
o Kowloon Canton &East West rail Hong Kong Bavarian Zugspitz Railroad, Germany
o Moscow Metro, Russia
o Penny Bay and HK Tram- Hong Kong
o Wuppertal Schwebebahn, Germany
o St Petersburg Citywide Network,
o Düsseldorf, Germany Mass Rapid Transit Authority (MRTA) MLY
o Made-berg, Germany
o Samsun Light Rail, Turkey
o Malaysia Express Rail Link – Malaysia
o Wiener Lokalbahnen, Germany
o Metro Bursa, Turkey
o Bangkok Metro, Thailand
o Bamberg, Bavaria, Germany
o Airport Skytrain Bangkok, Thailand
o Regionalbahn Bern-Solothurn, Switzerland
o Singapore MRT, Singapore
o Sytral – urban transit France
o KAZAKH RAILWAYS – RBTC, Kazakhstan
o North East & Circle Lines, Singapore
o Orleans Transport France
o Almaty Metro, Kazakhstan
o Marina Bay Line, Singapore
o RATP Railway & Metro & Tram – France
o Lille Metro & Tram – France