Which of the following is true of the Restricted Service?

When a phone shows your position on a map, it is working out where you are from the signals of satellites. For a long time, most of the world depended on satellite systems run by a few other countries. India decided to build a system of its own: the Indian Regional Navigation Satellite System, better known as NavIC.

As the word "regional" suggests, NavIC is not meant to cover the whole globe. Its primary service area is India itself and the region up to 1,500 km beyond India's borders. Within that area, it is designed to give a position accurate to better than 20 metres.

The system offers two kinds of service. The first, the Standard Positioning Service, is open to everyone. The second, called the Restricted Service, is encrypted and available only to authorised users.

The possible uses are wide. NavIC can guide vehicles on land, ships at sea and aircraft in the air, help manage disasters, track fleets of lorries, and give travellers and hikers a way to find their route. It can be built into mobile phones, and it can supply precise timing, which matters to many modern systems. Having a system of its own also means that India does not have to rely on another country's satellites for any of this.