Welcome to part three of BAI’s blog series exploring the top five challenges of providing wireless service in underground environments. This week we’re looking at working in confined spaces.

Coping with confinement

Delivering high-speed wireless connectivity in any location means finding suitable places to install sensitive electrical equipment. This can present challenges in any environment, however, these are multiplied when dealing with underground railways.

By their nature, metro rail systems are confined environments, ceilings are often low, and space is at a premium. Any location used for telecoms equipment needs to provide interference-free communications coverage, protect equipment against damage, and restrict unauthorised access. Additionally, installations must meet the transport authority’s station aesthetic and layout expectations.

Plan ahead to get ahead

Unfortunately, there’s no one technology or approach that can address this issue – the solution requires highly detailed planning. This includes surveying every equipment location in every station and tunnel to ensure compliance with requirements.

As mentioned in a previous post, ensuring you have the right equipment enclosures is vital too – even if these have to be created from scratch. They need to be secure, compact, but also easily accessible for future maintenance. Getting this wrong can have significant consequences. Dust, humidity or unauthorised access all have the potential to cause equipment failure and even fire.

Accuracy and innovation

Technology can play a huge part in the planning process. During the roll out of one of Hong Kong’s metro communications networks, Radio Frequency Engineering (RFE), a BAI Communications company, needed to guarantee that trains would not strike the newly installed equipment. To provide the level of precision required, they conducted laser-based measurement of every site.

Meanwhile, in New York, Transit Wireless, a BAI Communications majority-owned company, introduced 3D visualization similar to that used by Google in its Street View application to speed up the entire planning process. Transit Wireless was able to show station planners how the installation would work once in use, highlighting the best locations for equipment whilst ensuring the right aesthetics were maintained. While this approach provided a highly accurate way of demonstrating compliance, it also saved the time, hassle and expense of frequent site visits.

The importance of education

This combination of in-depth preparation and high-tech solutions is at the heart of how BAI ensures complex deployments run smoothly and efficiently. In tricky environments it’s the only way to deliver reliable and high-performance mobile communications to passengers.

That said, there is one more consideration – equipment will often sit in shared spaces, making it challenging to control access by other groups. Something as simple as a contractor hanging a frame from a coax cable can cause a dip in performance. Providing support and education after installation is as important to ongoing performance as getting the deployment right in the first place.

Read more

In this five-part series, we discuss the five challenges of building communications network in underground networks

  1. Part one: Dealing with dust
  2. Part two: Running complex projects without disrupting passengers
  3. Part three: Delivering communications in confined spaces
  4. Part four: Developing subterranean skill sets
  5. Part five: Aligning transport and telecom business models