Voice Over WiFi

Why in the News?

Bharat Sanchar Nigam Limited (BSNL) recently launched Voice over WiFi (VoWiFi) services across all telecom circles in India, enabling users to make voice calls and send SMS using Wi-Fi networks.
The nationwide rollout marked a significant step in BSNL’s network modernisation and aimed to improve call connectivity in indoor locations and remote areas with weak mobile signals.
The service was announced at the beginning of 2026, expanding digital communication access without additional cost to subscribers.

Voice over WiFi (VoWiFi), also known as Wi-Fi Calling, is a telecom technology that allows users to make and receive voice calls and SMS over a Wi-Fi network instead of a cellular tower.
It operates using the same mobile number and default phone dialer, ensuring a seamless experience similar to regular mobile calling.
The service does not require any third-party application, as it is built directly into the smartphone’s operating system.
VoWiFi is based on IP Multimedia Subsystem (IMS) architecture, which provides carrier-grade call quality, reliability, and security comparable to traditional mobile networks.

Wi-Fi connectivity enables call initiation, as the smartphone connects to a home, office, or public Wi-Fi network when cellular coverage is weak or unavailable.
SIM-based authentication verifies the user’s identity, ensuring secure access similar to conventional mobile calls.
Voice signals are converted into digital data packets and transmitted over the internet using Voice over Internet Protocol technology.
Seamless handover ensures continuity, as ongoing calls automatically switch between Wi-Fi and cellular networks without call drops when network conditions change.

IMS-based service architecture allows smooth transitions between Wi-Fi and mobile networks, maintaining call continuity.
Use of existing mobile number and dialer ensures familiarity and ease of use for subscribers.
No additional charges are levied, as Wi-Fi calls are treated like normal voice calls under existing plans.
Improved indoor and remote connectivity supports reliable communication in basements, offices, high-rise buildings, and rural areas.
Reduction in mobile network congestion occurs as voice traffic is offloaded from cellular towers to Wi-Fi networks.
Wide smartphone compatibility enables most modern devices to access VoWiFi through a simple settings option.

Enhanced connectivity in underserved regions supports digital inclusion, especially in areas covered by broadband initiatives such as Bharat Fiber.
Better call quality and reliability improve user experience in signal-dark zones.
Efficient use of network resources strengthens overall telecom infrastructure by reducing pressure on mobile towers.
Strategic public sector role of BSNL is reinforced in expanding affordable and resilient communication services nationwide.