The Challenge
The Washington Metropolitan Area Transit Authority (WMATA) was created by an
interstate compact in 1967 to “plan, develop, build, finance, and operate a balanced
regional transportation system in the national capital area”. The Metrorail system
currently serves 86 stations and has 106 miles of track and, combined with Metrobus,
serves a population of 5 million within a 1,500 square mile jurisdiction. The Metrorail
system will eventually connect the region’s two main airports (Dulles International and
Reagan National) with the new Silver Line currently under construction.
WMATA operates a Comprehensive Radio Communication System (CRCS) in the 490MHz
band to service this large network. There is also the need for providing 800MHz radio
coverage for 1st responders for Arlington County. This means having to ensure radio
coverage in various challenging environments including underground in the metro tunnels
and stations, and above ground in the various parking garages and stock yards owned
and run by the authority.
Cobham Wireless has had the benefit of working closely with WMATA, being called in to
support their local DC System Integrator partners to solve some of these radio coverage
challenges. Since 2005 Cobham Wireless has been working closely with the authority to
support the on-going augmentations and retrofits to the legacy coverage systems by offering key design support and supplying the equipment required to make this happen.
The Solution
Cobham Wireless has been able to utilize its vast global experience in Metro Solutions to
provide support to our System Integrator partners on these project requirements.
Cobham Wireless was able to provide product and engineering support in the following
key areas.
- 490MHz line amplifiers to replace current obsolete units
- Outdoor channelized repeaters using state of the art digital signal processing
(DSP) technology for the in-fill coverage in the parking garages and stock yards
- Redundant head-end for the 490MHz/800MHz systems, incorporating a DSP
filtering technology ‘noise gating’ system, allowing for the balancing and
improvement of noise levels generated from the legacy fiber optic remote
system. Consequently improving the dynamic range of radio coverage from
below ground to above ground. This ‘gating’ is done by allowing channel
modules to activate on a pre-defined squelch level, resulting in decreased overall
noise levels and better performance on the system
- Fiber optic fed repeaters for coverage of the stations along the new Dulles
- 490MHz line amplifiers to replace current obsolete units Corridor network as well as 800MHz coverage for the legacy 800MHz FO system
- All of the above systems offer high ‘mean time between failures’ (MTBF)
performance thereby ensuring and supporting WMATA’s system reliability and
performance.
The Benefit
With an increased focus on safety for travellers and passengers in recent years not only
in the US but globally, ensuring a secure and reliable public safety communications
systems was vital for this project. Constant upgrades and improvements to legacy kit are
necessary to keep passengers and staff protected.
The WMATA benefits from a leading-edge communications system that will provide public
safety services with the means to communicate with each other in a secure and reliable
fashion.
The improvements made mean that the communications system is increasingly flexible
and future-proofed against technology upgrades and changes – and with the speed at
which technology evolves nowadays, this is no mean feat. The authority benefits from
Cobham Wireless equipment that has a global reputation for being of the highest quality,
while being dependable and reliable in terms of its performance out in the field. Cobham
Wireless’ communication equipment will continue to serve the emergency services and
the passengers of Washington for a long time to come.
