UK Building GPS-Alternative Network
The UK is launching an $180 million initiative to create a terrestrial timing signal network. The goal is to reduce reliance on vulnerable satellite-based timing (GPS/GNSS) for critical infrastructure like mobile networks and banking, underscoring the growing demand for engineers skilled in high-precision clocking circuits.
The initiative, known as the National Timing Centre (NTC) programme, is led by the UK's National Physical Laboratory (NPL). It aims to create a sovereign and resilient national timing infrastructure by developing and integrating various technologies, including fibre optic links, communication satellites, and terrestrial broadcasts. This move is designed to reduce the UK's heavy reliance on Global Navigation Satellite Systems (GNSS) like GPS. GNSS signals are susceptible to both natural and man-made threats. These include solar storms, atmospheric disturbances, and deliberate attacks like signal jamming, which overpowers the weak satellite signals, and spoofing, where false signals are transmitted to deceive receivers. A 24-hour outage of satellite navigation services is estimated to cost the UK economy around £1.4 billion. A key component of the terrestrial network is the Enhanced Long-Range Navigation (eLoran) system. eLoran utilizes high-power, low-frequency (90-110 kHz) ground-based transmitters that are less vulnerable to jamming and can penetrate locations inaccessible to satellite signals, such as inside buildings. The UK is investing £71 million to establish a national eLoran program, with an operational transmitter already located at Anthorn. To ensure precision, the NTC programme is also leveraging quantum technology. The UK Quantum Technology Hub in Sensors and Timing, a collaboration involving seven universities, is developing next-generation atomic clocks and sensors. These quantum systems aim to provide ultra-precise timing for applications like advanced radar systems and secure communications, independent of satellite inputs. The NTC is building a network of innovation nodes at universities like Strathclyde and Surrey to facilitate R&D for industries that rely on precise timing. For the financial sector, where transactions are time-stamped to the microsecond, the NPL already offers a fibre-based service called NPLTime® that provides a direct, GNSS-independent link to the national timescale, UTC(NPL). Recently, the NPL upgraded its Network Time Protocol (NTP) service as part of the NTC initiative. This involves increasing the number of stratum 1 servers, which are directly synchronized to atomic clocks, from two to five, located across three different sites to enhance resilience and provide a robust, ground-based alternative for synchronizing digital systems across the country.
