In early 2014, Sound Transit received seven proposals—which represent the majority of firms nationwide with the capacity to meet the requirements of the RFP [fund, design, build, operate and maintain an underground mobile wireless system for cell phones].

Mobilitie will pay [Sound Transit] ongoing monthly payments beginning when the wireless communication coverage is activated, at $7,500 per month, and as all four major carriers get enlisted the payments could grow to $10,000 per month, for the life of this agreement.