VoLTE (Voice over LTE) is more than just a technical upgrade; it is a fundamental shift in how your mobile functions. By treating voice as high-speed data, it unlocks a professional-grade calling experience that older 2G and 3G networks simply cannot match.
1. High-Definition (HD) Voice Quality
VoLTE utilises wider bandwidth and advanced "codecs" (audio compression) to deliver superior sound.
The Result: Crystal-clear conversations that sound more like a face-to-face meeting. Background noise is minimised, and the "muffled" audio of traditional mobile calls is eliminated.
2. Instant Call Connection
On older 3G networks, you might wait 5–10 seconds for a call to start ringing after hitting dial.
The Result: VoLTE routes calls almost instantly. This is especially critical for OnSim users with paired IP Deskphones, as it ensures both your mobile and desk phone ring simultaneously without any lag.
3. Simultaneous 4G Data & Voice
Before VoLTE, your phone had to "drop down" to 3G or 2G to place a call, which effectively throttled or cut off your internet connection.
The Result: You can stay on a call while simultaneously using 4G/5G data to check an email, look up a location on a map, or use a business app—all at high speed.
4. Improved Battery & Energy Efficiency
Operating multiple radios (switching between 4G for data and 3G for voice) drains your battery faster.
The Result: Using a single, modern 4G network for everything is more energy-efficient for your device. Furthermore, UK operators estimate that decommissioning old 3G infrastructure reduces total network energy consumption by approximately 20%.
5. Efficient Network Performance
By using one streamlined network for both voice and data, the carrier can manage traffic more effectively.
The Result: Better overall network capacity and fewer dropped calls, even in crowded areas where traditional 2G/3G bands might become congested.
6. Future-Proof Connectivity
As UK networks "sunset" (turn off) their 3G and 2G services, VoLTE is no longer just a luxury—it is the standard.
The Result: Ensuring VoLTE is enabled guarantees that your device will remain fully functional as older network technologies are retired.
How to Enable VoLTE
If you don't see the VoLTE or 4G icon during a call, you may need to activate it manually: