Investment in railways is increasing across the world as the rail industry targets competition with airlines. The trains themselves are becoming faster and more luxurious to reflect this. However, that has resulted in them costing more and therefore needing to be in use more often to justify that cost.
Rail networks, therefore, have an increasing need to manage and communicate with their fleets across their networks, along with ensuring personnel are available at the right time and maintenance is conducted in an efficient and timely way.
In Europe, in particular, the rail industry has relied on GSM-R, a development of the GSM standard specifically designed to address the needs of rail industry. However, that technology is now starting to age and, although there will be an upgrade path to the higher bandwidth technologies in the GSM family – namely LTE – that is unlikely to see deployment before 2020.
That delay is largely because of the vast areas that rail networks cover and the time it will take for rail operators to upgrade those networks. It will be a large and costly project and, today, GSM-R still provides an effective means to operate rail networks.
GSM-R is not the only option available to rail operators and, as a European-defined standard, it has had the greatest success in Europe. TETRA, which has had some success in metro networks, is being taken up in the Asia Pacific region, and has been adopted in some European markets to support the signalling and control function defined in rail industry standards such as ETCS – the European Train Control System.
‘In Europe, for example, GSM-R – which is an enhanced version of the GSM standard developed nearly twenty years ago specifically to deliver the cross-border transparency needed to support international train operations across the continent – is now showing its age with no defined evolutionary path for supporting higher bandwidths,’ says Tom Quirke, vice president and general manager of the Global TETRA Organisation, at Motorola Solutions.
‘In addition, its slow roll out in Europe and limited take up elsewhere in the world has led to a number of the original vendors pulling out of the market, restricting customer choice still further. That has also limited economies of scale and lower costs for both infrastructure and devices made possible by a global marketplace,’ says Quirke.
Others emphasise the technology’s specific strengths. ‘GSM-R is the only system designed for the railways by the railways, together with the industry,’ says Dirk Lewandowski, head of Nokia Solutions & Networks (NSN) Railway Solutions.
‘GSM-R is the only system, which is completely specified, developed and validated for railway purposes of up to high speeds of 500km/h. All national interfaces are available from public GSM allowing for international roaming and interoperability. The huge installed base guarantees a scale of economy and a qualified customer service support.’
Lewandowski points out that NSN has deployed more than 30 GSM-R networks in 21 countries serving some 50,000km of railways.
However, Quirke says that, when compared with TETRA, which was designed from its start to deliver mission-critical wide area coverage, GSM-R also involves more capital expense and greater operating costs.
‘Call set-up times can be both slow and variable, while data applications for train control in a predominantly IP-based world are difficult to support with the native circuit switched data service of GSM-R,’ he says. ‘TETRA, by contrast, has both MSPD (Multi-Slot Packet Data) and TEDS (TETRA Enhanced Data Service) to draw upon for these functions.’
P25 – the US digital public safety system – has seen limited take up, while many countries are still reliant on traditional analogue VHF/UHF systems to control rail operations.
Trains themselves are becoming increasingly smarter and their growing cost means that they must be used as much as possible. ‘TETRA-supported applications such as being able to automatically monitor the health and status of the various on-board systems such as air conditioning, lighting, wheel and brake wear – or remotely control them – can deliver valuable savings in both maintenance and repair while also contributing to overall safety and reliability,’ adds Quirke.
Lewandowski feels that GSM-R has just as much to offer. ‘When combining GSM-R and ETCS it will be possible for trains to get real time information about movement authority, thus minimising breaking and acceleration, reducing energy consumption and minimising emission of greenhouse gases,’
Location-based applications are a second key area for TETRA-enabled communications. ‘While GPS may operate effectively in open long-haul environments, it runs into difficulties in urban areas where tunnels, cuttings and tall buildings may block signals,’ says Quirke. ‘Here, alternative technologies such as wheel turn or trackside sensors using RFID or Bluetooth can be used to gather data for onward transmission.
TETRA also has the ability to communicate voice securely and reliably in a number of different ways through person-to-person, group and broadcast calls.
Systems can also be used to both remotely speak to passengers on train, accept calls from emergency help points on those trains, or broadcast messages on service status to on-train displays to keep passengers informed.
However, Lewandowski sees the eventual upgrade to 4G LTE resulting in GSM-R being able to offer rail operators more. ‘As with all mobile communications, Long Term Evolution (LTE) radio access technology is set to transform GSM-R with higher data speeds, improved user experience and more cost-effective, IP-based operations,’ he adds, while acknowledging there are challenges to overcome.
‘However, the change to LTE will require extensive technical and regulatory standardisation to ensure [the] required functionality, full interoperability and a seamless migration from GSM to the LTE platform. The transition is therefore not expected to be completed until around 2020.’
Mecca-Medina high speed line chooses GSM-R
Kapsch CarrierCom is supplying GSM-R technology to ensure safe train operations on the 450km high-speed line between the Saudi Arabian cities of Mecca and Medina. The technology based on ERMTS (European Rail Management Traffic System) level 2 will be used on the Islamic pilgrimage route.
The new high speed rail line from Mecca through Jeddah to Medina will connect multiple urban regions as well as the international King Abdullah Airport. The route features expansive stretches of desert with difficult climatic conditions and high temperature fluctuations.
In addition to the climatic and topographical challenges in construction and operation of the technical equipment along the rail line, consideration must be given to the religious and cultural significance of this route.
Islamic pilgrims from all over the world will in future travel through Saudi Arabia to the holy sites at speeds of up to 320kmh. Railway communication based on GSM-R technology is an important prerequisite for safe and smooth operation of this railway line.
In order to ensure this, a fail-safe architecture was designed with built in redundancy. The network coverage along the railway line is fourfold. In other words, if three base stations in a region fail, a fourth can still serve the entire area. ‘We were able to win this project in particular because security, safety and expertise were key criteria. We acquired experience with similar environmental conditions in a project in Algeria and we have already equipped multiple railway stretches with similarly advanced solutions supporting ERTMS Level 2 in high speed environments,’ says Michel Clement, vice president of railways at Kapsch CarrierCom, which will operate the GSM-R infrastructure for 12 years.