Track To Train CCTV System

Track To Train CCTV System

Our proven microwave system transmits high-quality dynamic images from the platform CCTV cameras to drivers of Driver Only Operated (DOO) trains as they approach and leave stations. In-cab monitors clearly show the entire length of the train and platform interface until the whole train has safely departed the station. The system is suitable for surface, sub-surface and underground railways, and platforms of any types both with and without platform edge doors.

Global Railway Operators using Ogier Equipment

Advantages Of Microwave Transmission

The video transmission system does not compromise resolution or frame rate, with the picture quality guaranteed and measured using quantifiable parameters. Spatial diversity is employed using separate antennas to ensure videos are unaffected by multi-path interference, even underground. Licensed frequency bands are utilised to guarantee interference-free operation.

The compact microwave transmitters are inside durable solid metal housings. The placement and position of the transmitters is subject to fewer limitations than for leaky feeder systems that must run the fragile feeder cable along the edge of the platform making it vulnerable to damage or misalignment.

Zero latency video displayed inside the drivers cab

The analogue PAL transmission employs wideband frequency modulation, providing the driver with real-time, zero-latency images of the platform. The video clarity can be observed in the image below, captured at a London Underground station during system commissioning.

Advantages Of Fixed Platform Cameras

On curved platforms, the cameras can be arranged strategically to achieve complete coverage. Platform cameras are positioned to avoid glare from platform lighting and railway signals.

Compared to train-mounted cameras, fixed cameras are not subject to vibration and can utilise larger, high-quality lenses and optics for bright, clear video. Train-mounted cameras often have to compromise due to restrictive loading gauges.

Up To 8 Live Camera Feeds Per Platform

The system can transmit one or two video channels, each of which can be used to show split screen displays of several cameras. Up to four cameras can be shown on a single screen, for a maximum of eight platform camera views across two screens, as utilised for some historic London Underground platforms with extreme curvature or obscured sight lines.

Operating Frequency Choices

Variants of the system can be supplied to enable operation in all the licenced bands up to 31 GHz. Thus, unlike Wi-Fi based systems that operate in the public, licence exempt bands, the system can be guaranteed to be interference free, which is particularly important for a safety related application of this sort. Multiple sub-channels are utilised as required to prevent crosstalk from adjacent platforms.

Digital DVB-T option

Either digital DVB-T or analogue PAL FM can be deployed. Both provide broadcast quality video. Digital modulation is preferred if long range transmission is required and there are many non line of sight conditions. There is however some latency due to the processing but this is reduced to less than 50 mS. Alternatively, if the ranges are moderate and there is generally a line of sight, analogue is recommended because there is no latency and no loss of resolution. To date, all of our customers have chosen to use PAL FM analogue modulation.

A Typical System In Daily Use

In London, the Ogier Microwave transmission system is currently in use on four sub-surface railway lines, including 240 platforms at 105 stations.

Every day 270 microwave transmitters send 650 live camera views to the fleet of 192 S-stock trains, all of which are fitted with Ogier microwave receivers.

The system has best in class reliability and picture quality.

Robustness and Reliability

Routine or scheduled maintenance is not required, reducing operational burdens. In the event of a reported fault, simple depot checks diagnose train-born equipment, ensuring smooth operation. Full status information for all platform equipment is output continually, enabling effective monitoring and management.

The microwave transmission system is not susceptible to environmental contamination for example from brake dust. The circuit boards are housed in rigid machined aluminium housings for protection from impacts, shock and vibration. O-ring gaskets are used to seal access panels, preventing water or dust ingress. Special attention has been paid to the power supply circuits to protect from the voltage spikes and power surges that are experienced in railway environments.

The result of our design efforts has yielded an enviably low mean time between failures (MTBF) for the equipment as demonstrated since first deployment in 2001.

Adaptable Design

The core design concepts are similar for every system, but a number of adaptations have been made to suit the particular requirements of each railway.

We have systems that use dedicated “ON” and “OFF” beacons to enable/disable the video. Other systems use a “ON” beacon and the receiver’s “squelch” function. Another railway uses train information system (TIS) and squelch, omitting beacons entirely.

We have a number of different operating frequency bands that are utilised for video transmission, ranging from 12 GHz to 31 GHz, resulting in a variety of antenna, frequency converter designs.

Most systems transmit directly to the front driving cab, but one particular system transmits to the rear cab, necessitating a further adaptation to the core design to overcome complications due to the intricate train routing and track layout at some stations on the line.

Furthermore, we have trialled a two way system in underground and over-ground environments that allow bi-directional data transmission as well as videos from on-board cameras to be transmitted to a central control point via trackside receivers. The microwave frequency bands have ample bandwidth to support additional data channels and two-way operation.

If you have a specific requirement or would like to discuss the system with us, please do not hesitate to contact us.

  • Underground Railways
  • Metro Systems
  • Light Rail
  • Trams
  • Driver Only Operation (DOO)
  • One Person Operation (OPO)
  • Driver Controlled Operations (DCO)

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