1. Short title This Act may be cited as the National Timing Resilience and Security Act of 2017 . 2. Backup global positioning system (a) In general Subject to the availability of appropriations, the Secretary of Transportation, in consultation with the Secretary of Homeland Security, shall provide for the establishment, sustainment, and operation of a land-based, resilient, and reliable alternative timing system to— (1) reduce critical dependencies and provide a complement to and backup for the timing component of the Global Positioning System (in this section referred to as GPS ); and (2) to ensure the availability of uncorrupted and non-degraded timing signals for military and civilian users in the event that GPS timing signals are corrupted, degraded, unreliable, or otherwise unavailable. (b) Establishment of requirements (1) In general Not later than 180 days after the date of the enactment of this Act, the Secretary of Transportation, in consultation with the Secretary of Homeland Security, shall establish requirements for the procurement of the system required by subsection (a) as a complement to and backup for the timing component of GPS in accordance with the timing requirements study required by section 1618 of the National Defense Authorization Act for Fiscal Year 2017 ( Public Law 114–328 ; 130 Stat. 2595). (2) Requirements The Secretary of Transportation shall ensure, to the maximum extent practicable, that the system established under subsection (a)— (A) be wireless; (B) be terrestrial; (C) provide wide-area coverage; (D) deliver a precise, high-power 100 kilohertz signal; (E) be synchronized with coordinated universal time; (F) be resilient and extremely difficult to disrupt or degrade; (G) be able to penetrate underground and inside buildings; (H) be capable of deployment to remote locations; (I) take full advantage of the infrastructure and spectrum of the existing, unused government long-range navigation system (commonly known as LORAN )