If you own a smartphone in Nepal, you may have noticed notifications from telecom operators like Nepal Telecom (NTC) and Ncell about VoLTE and VoWiFi services.

While many users are curious, few fully understand what these technologies are, how they work, or why they matter. Some users have not yet enabled them, while others may already be using them without realizing it.

If your phone supports these services, you might see a small VoLTE or VoWiFi icon near the network signal. If not, enabling them is straightforward, but first, it is important to understand their purpose and benefits.

What is VoLTE?

VoLTE (Voice over Long Term Evolution) is a technology that allows voice calls to be made directly over a 4G LTE network, instead of dropping to older 2G or 3G networks as in traditional calling. In conventional systems, voice calls use circuit-switched networks (2G/3G), while data services operate over packet-switched networks (3G/4G). Without VoLTE, making a call on a 4G phone often forces the device to switch to 3G or 2G, temporarily stopping mobile data.

VoLTE overcomes this limitation by converting voice into digital data packets and transmitting them over the LTE network using IMS (IP Multimedia Subsystem) technology. This allows simultaneous voice and data use, faster call setup, and high-definition (HD) voice quality. VoLTE also enables video calling over cellular networks if both parties support it, and all calls are charged at the regular voice call rate.

Key Technologies Behind VoLTE: IMS manages IP-based voice services, SIP (Session Initiation Protocol) handles call setup and termination, advanced codecs like AMR-WB and EVS deliver HD voice, and QoS (Quality of Service) prioritizes voice packets for clear and stable calls.

Benefits of VoLTE include clearer and more natural-sounding voice, almost instant call connections, the ability to use mobile data while on a call, and more efficient network usage. However, it requires a compatible smartphone and support on both caller and receiver networks. Early implementations may slightly increase battery consumption.

What is VoWiFi?

VoWiFi (Voice over WiFi), also known as WiFi Calling, allows users to make and receive calls over a WiFi network instead of a cellular network. This service is especially useful in areas with poor mobile reception, such as inside buildings with thick walls, basements, offices, or remote locations.

VoWiFi also uses IMS technology but transmits calls via WiFi, securely encrypted using IPSec tunnels. Calls are still routed through the operator’s network, not third-party apps like internet calling apps.

Supporting Technologies: IMS handles call control, IPSec ensures secure transmission, EAP-AKA authentication verifies SIM-based identity over WiFi, and seamless handover allows switching between WiFi and LTE networks during ongoing calls.

Benefits of VoWiFi include the ability to make calls even in no-signal areas, improved indoor coverage, standard voice call charges with no extra cost, and potentially better battery efficiency in weak cellular signal zones. However, call quality depends on WiFi stability, and support may be limited on some devices or networks. Emergency call location tracking may also be less accurate than traditional cellular networks.

Why Operators Promote VoLTE and VoWiFi

Telecom operators like NTC and Ncell actively promote VoLTE and VoWiFi because these technologies improve overall user experience while reducing dependence on legacy 2G and 3G networks. They also optimize network usage, reduce congestion, and prepare infrastructure for future 5G deployment, ensuring better coverage and service quality for all users.

How to Enable VoLTE and VoWiFi

Most modern smartphones allow users to enable these services easily. Go to Settings → Mobile Network → VoLTE / WiFi Calling → Enable. In Nepal, quick activation codes are also available: for Ncell VoLTE, dial *123*11#, and for NTC VoLTE, dial *444*2#. Some phones may require a software update or operator provisioning before these services become active.

Conclusion

VoLTE and VoWiFi are not just marketing terms—they are the future of mobile communication. By enabling them, users can enjoy better call quality, faster connections, improved indoor coverage, and the ability to use mobile data while on a call. As Nepal moves toward advanced LTE and 5G networks, turning on VoLTE and VoWiFi ensures a smoother, more reliable, and high-quality mobile experience.