Context: Recently, India's State-owned telecom operator BSNL has launched India’s first Direct-to-device satellite connectivity, a game-changing service that aims to bridge the connectivity gap in remote areas.

Key highlights

• This service utilizes advanced satellite technology to deliver high-speed internet directly to user devices, bypassing the need for traditional infrastructure.

• It marks a major event in extending satellite communications to everyday consumers which were earlier limited to emergency and military use.

• Global initiatives such as AST SpaceMobile, Lynk Global, Constellation Global, SpaceX- Starlink are also uses D2D technology.

Working of Direct-to-Device Satellite Technology

• Principle: Satellites act as cell towers in space, bypassing the need for terrestrial cell towers as used in traditional mobile connectivity.

• It uses satellites in orbit to transmit signals directly to devices on the ground.

• Non-Terrestrial Network (NTN) technology: It allows for seamless two-way communication between devices and satellites.

• BSNL uses Viasat’s Geostationary L-band satellites positioned 36,000 kilometers above which bypasses ground-based cell towers, making it ideal for remote coverage.

Significance

• Reliable connectivity: Uninterrupted internet connectivity, regardless of weather conditions.

• High-speed internet and wider coverage even in the remotest areas  where cellular or Wi-Fi networks are unavailable. 

• Support UPI payments: Empower people in rural or underserved regions to make digital transactions

• Emergency calls and SOS messaging: Communication in emergency situations where cellular or Wi-Fi networks are unavailable( useful for adventurers, travellers etc)

Challenges 

• Latency: Ensuring minimal delay for real-time applications like voice calls and video streaming.

• Regulatory Challenges: As D2D service may cross geographical borders

• Spectrum allocation: Obtaining sufficient bandwidth for seamless satellite-to-ground communication.

• Device compatibility: Ensuring technology works across various smartphones and operating systems.

• Propagation challenges: Overcoming signal loss and interference in diverse environments