Terminology » LTE » LTE vs VoLTE: Key Differences Explained

LTE vs VoLTE: Key Differences Explained

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voice over lte
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This article delves into the distinctions between LTE (Long Term Evolution) and VoLTE (Voice over LTE), explaining how each technology handles voice calls within the framework of an all-IP network.

Introduction

LTE was primarily designed to support data-centric applications. However, it’s also capable of facilitating voice calls. Because LTE operates on an all-IP network, there are two primary methods for enabling voice communication:

  1. Voice over IP (VoIP) with IMS Support: This method leverages VoIP technology alongside the IP Multimedia Subsystem (IMS) to route voice calls over the LTE data network.
  2. Legacy Fallback: The device falls back to older cellular networks like 2G/GSM or 3G/CDMA for voice calls when VoLTE isn’t available.

Many mobile phones don’t natively support VoLTE, necessitating the installation of converter applications to utilize the VoLTE feature.

Benefits of VoLTE

  • Faster Call Setup: VoLTE boasts significantly faster call setup times compared to older 2G and 3G networks.
  • Improved Battery Life: VoLTE is designed to be more power-efficient, extending battery life.
  • High-Definition Voice Calls: VoLTE enables high-quality (HD) voice calls, providing a richer audio experience.

The diagram below illustrates the architecture of VoLTE using VoIP protocols through IMS.

VoLTE using VOIP through IMS

LTE vs. VoLTE: A Detailed Comparison

The following table summarizes the key differences between LTE and VoLTE.

SpecificationsLTEVoLTE
Full FormLong Term EvolutionVoice over LTE
Main applicationDeveloped primarily for data-only applications. LTE = Only Data TransmissionDeveloped to support both voice and data transmission. VoLTE = Call + Data Transmission
Quality of Voice transmissionVoice quality can degrade when a data connection is active.Voice quality remains excellent even with an active data connection.
Switching TypeUses packet switching exclusively.Leverages the existing packet-switched LTE network to deliver HD voice calls.
Call setupSlower compared to VoLTE.Much faster compared to LTE.
External application softwareRequires external applications like Skype or WhatsApp for video calling.Allows direct calls to anyone, regardless of whether they use an external application.
Free callingRequires a continuous internet data connection for free calls; the user can’t switch it off.Enables free calls even when the internet connection is switched off.
BatteryData and battery are significantly drained.Data and battery consumption are reduced compared to LTE.