Article

Mind the Step-Change in Rail Communications

Rail Technology Magazine, Dec/Jan 03/04

The adoption of mobile technology is breathing new life into the train networks. And given the maturity of mobile communications, a step-change is imminent. The potential of mobile communications is nowhere more obvious than in the railways, especially since the rail network is now viewed as the backbone of a future inter-modal transport system. It is clear to many in the industry that communications technology developed outside the railway industry presents the opportunity to bypass generations of internal development.

As the railway industry becomes more open to sharing knowledge with other industries, new opportunities for revenue generation and efficiency will undoubtedly arise. The Railway Industry Association's 'Value Improvement Programme' recognises the potential of using techniques already proven in other industries. This applies equally to the application of engineering R&D previously carried out at no cost to the railway industry. Up to now the focus has been mostly on essential maintenance and renewal expenditure. But to build a network which will stand the test of time, railway project managers must embrace recent advances in communications engineering.

For example, although not yet in widespread use, some recent innovative uses of various technologies include :

• GSM-R
  European railways have adopted proven GSM technology for a railway-specific communications network, ensuring that public safety is not compromised. In comparison, the higher data rates of UMTS are not possible at very high speeds in multipath fading environments.

• London Underground 'Connect'
  London Underground uses TETRA for their 'Connect' communications network. Voice and text messages can be sent in real-time between train driver, station and depot staff, increasing the speed of response to potentially disruptive events.

• SMS- and Web-enabled remote monitoring
  The condition of tracks, trains, signalling systems and local weather can be monitored, allowing preventative maintenance and early detection of equipment failure.

• Customer Information Systems
  Wireless communication networks are used to update passenger information boards in real time, and to provide information to mobile phone users.

• On-board WiFi, and Wi-Fi 'Hotspots' at stations
  Wi-Fi facilities will help the railways exceed passenger expectations of customer service.

• E- ticketing
  The 'Oyster' smartcard scheme being rolled out by London Transport bypasses the need for conventional ticket offices and barriers. It also provides information on individual passenger journeys that could aid prioritised network development and targetted pricing schemes. The use of mobile phones for purchasing 'virtual' tickets is also being investigated, along with using Bluetooth-enabled phones to allow passengers to board a train.

All these examples will increase revenue generation either directly or through increased efficiency. Given the existence of advanced technologies and the need for increased self-funding however, the degree to which revenue generation ceases as soon as a passenger boards a train is still surprising - much revenue generation is still effectively left behind at the station. On the train itself the focus remains traditionally on revenue-protection. And all because trains move.

Innovation

Technical know-how is often used most effectively and efficiently where cross-fertilisation of ideas between industries can occur. Plextek has helped train operators, signalling and control companies such as Westinghouse Rail Systems, and London Underground introduce new technologies in this way. New examples of our technologies that have potential applications in the railway industry include:

• Long-life battery-operated remote monitoring
  Low power telemetry modules (fig. 1) - currently undergoing trails in 50,000 homes by British Gas -could be used for monitoring or control applications. Battery life of up to 10 years can be expected as a result of the novel radio interface and comprehensive power management. Together with sensors for monitoring infrastructure such as bridges and tunnels, this could provide reliable remote monitoring independent of interruptions in rail power supply or public telecommunications networks. Combined with other expertise including the development of a new ultrasound sensor design, or X-ray CCD imaging, similar technology can be used for a range of portable instrumentation equipment.

• Low cost portable radar
  'Blighter' combines a commonly available PDA and a novel electronic scanning technique in a low cost portable radar unit. Operating from the driver's cabin, or as a safety system for track workers, this could provide cost-effective detection of obstructions or early warning of approaching trains with a range of up to 10km independent of local weather conditions.

• Asset location tracking
  Using our long-range, low power radio technology we have designed a location tracking system. Such technology transferred to the railway industry could enable 'fit and forget' radio systems for asset tracking, as well as monitoring for the effects of vandalism.

• Mesh Networks
  A highly innovative broadband radio access network - since commercialised by telecommunications company Radiant - employs a "Mesh" network of point-to-point microwave links between "Nodes" at customer premises, forming a distributed trunking network over which voice and data services are routed using ATM technology. This technique ensures minimal capital expenditure by creating a self-healing and expanding network.

Technical Constraints

The railway industry faces a unique set of challenges in using mobile technology. In particular it faces the technical challenge of distributing real-time information to both rural areas and also to the trains. This means that practical experience of antenna measurement (fig. 2) and of assessing a variety of rural and urban landscapes by RF surveying (fig. 3) is frequently necessary. In addition, a detailed understanding of the many modulation schemes available is required to determine the most appropriate technology. For example, fig. 4 shows the important trade-offs between some of the modulation schemes considered for the so-called "TETRA Release 2". These new proposals are intended to keep TETRA attractive in the light of oncoming UMTS by offering far greater bandwidth.

The 'Radio spectrum management review' by Professor Martin Cave published in October 2002 has also impacted the use of radio technology. Significantly for the railways, it proposed that "Firms that do not utilise, or under-utilise spectrum will have an incentive to lease or sell it". Increased deregulation is also to be accompanied by spectrum trading, which requires intelligent forecasting of use, revenue and a high degree of technical expertise in spectrally efficient and effective modulation schemes. Such requirements mean that strategic technical consultancy is often a necessity rather than a luxury.

Our engineers have carried out projects in a variety of industries including public transport, aerospace, defence, and medical. A common factor here is physically robust, technically demanding design and extreme reliability standards. Design for obsolescence is also a key issue to many such industries, leading to many implementations with in-field programmability. Physical robustness is ensured by the design and testing for shock and vibration endurance. Environmental testing such as repeated thermal cycling and testing for EMI and EMC compliance are essential for achieving a well-engineered system.

It is no big secret that funding in the railways is still not truly at an all-time high and must continue to be used with great care. A technical design house with experience of separating the wheat from the chaff in the use of technology across a range of industries is therefore invaluable.

Written by Esther Ford