Refresh the page

Internet calling: What hides under the terms HD Voice, VoLTE or WiFi calling?

Updated • Author: Ondřej Chabr

Technologies like HD Voice increase quality of phone calls. In addition, calling via WiFi or VoLTE allows you to make calls even in places where the operator' s signal is not ideal. What do you need in order to try these services?

Volání přes internet

Internet calling - HD Voice, WiFi calling and VoLTE - CONTENTS

  1. HD Voice technology for clear sound when making calls
  2. Telephone connection even with poor signal reception thanks to VoLTEE
  3. WiFi calling allows you to make calls, but also text only using the WiFi networkk

HD Voice technology for clear sound when making calls

As the name suggests, this designation speaks about technology of better sound transmission. In a conventional telephone call, audible noise is always present, and this connection is of course also greatly affected by the reception of the operator' s signal. HD Voice relies on the high-quality AMR-WB audio codec to transmit higher data rates and a wider range of frequencies.

i The range of standard telephone calls is 300–3 400 Hz, while the HD Voice range is much wider, namely 50-7,000 Hz.
This makes it possible to achieve a clearer sound without noise and ambient noise. Your voice will be heard much better by the other party, similar to as if you were standing next to each other.
HD Voice
Rozsah HD Voice s noticeably wider, so it is possible to transmit clearer sound without the ambient noise. Source:

Not only the caller, but also the called party must communicate with a mobile phone with HD Voice support. But don' t worry, HD Voice is automatically present in the vast majority of modern smartphones. You can check whether your phone also supports it in the manufacturer' s parameters, and if you have T-Mobile, just call 4004 to verify compatibility.

Operator support is also required. T-Mobile was the first to launch technology in 2011, and after 4 years Vodafone also joined it. You can call in their networks and between them. Function works without the participation of the O2 operator for now. You don' t pay anything extra to your carrier for this practical improvement of phone calls. All you need is 3G reception.

Telephone connection even with poor signal reception thanks to VoLTE

Operators are currently trying to expand the coverage of our country with a 5G signal for the fastest mobile internet. The previous 4G LTE technology is, of course, extensive in our territory. You can use this to your advantage not only for fast mobile data transfers, but also better calls via the VoLTE service. However, in addition to better sound, thanks to the transmission of voice over the data network, you can also call in places where the phone shows you poor or no signal reception at all..

i 5G network is rapidly entering the competition.

So you can call from the cellar, from the cottage in the deep woods or anywhere, where otherwise you would not be able to pick up the mobile signal at all. In addition, you can set up a video calls and this service is called ViLTE. And what is necessary for proper VoLTE functionality?

What is needed in order to use VoLTE?

  • LTE SIM card.
  • Phone, supporting this function. Support is stated in operator requirements and listed on the operators' website or in the device parameters.
  • VoLTE is supported by all 3 main operators, but make sure you have the active function and also the correct firmware update from the operator.

Am I paying anything extra? Is data from the data package used for it?

For a call via VoLTE (or ViLTE) you pay according to the operator' s price list in the same way as for a normal GSM call. The data used for the call is not counted as consumed from your data packet.

Is it possible to make calls from abroad?

This function is not supported abroad.

Do both parties have to meet the conditions for making a VoLTE call?

The called party does not have to meet the VoLTE conditions, they can easily have an older push-button telephone and you can still contact this person from anywhere with LTE reception. However, if the other party is also ready for VoLTE and is ideally in the network of the same operator, the voice transmission will be noticeably better. The individual parameters of the function differ from operator to operator.

The VoLTE and ViLTE services are therefore actually calls over the Internet using the LTE signal, yet you pay for them as for a normal telephone call in the mobile network.

WiFi calling allows you to make calls, but also text using only the WiFi network

Calling via WiFi, or also VoWifi, is in fact the same as with the use of LTE transmission. So you don' t have to rely on the presence of a mobile network at all. All you need is WiFi internet reception, a supported phone and the WiFi call function activated.

In addition to calling, our operators also support the option of sending text messages or switching to a video call. Everything is usually charged according to the operator' s price list as a normal telephone call.

How to set up a WiFi calls on a smartphone?

  • Android: Phone – Settings – WiFi calls
  • iOS: Settings – Phone – WiFi calls

What if the WiFi connection disconnects during a call?

The phone should switch to a standard call automatically, without disconnecting. You will probably notice the transition to a classic call via the GSM network by a deterioration in sound quality.

Aktivace Wi-Fi volání
Don' t forget to turn on the service in your phone settings.
i Might interest you

Calling using WiFi or LTE is suitable not only for those who want to call from places with poor signal coverage, but will come in handy to anyone who appreciates clearer audio and improved overall call quality. HD Voice technology will offer good quality call sound even via classic mobile GSM calls.

We care about your privacy a. s., Company identification number 27082440, uses cookies to ensure the functionality of the website and with your consent also to personalisage the content of our website. By clicking on the “I understand“ button, you agree to the use of cookies and the transfer of data regarding the behavior on the website for displaying targeted advertising on social networks and advertising networks on other websites.

More information
I understand Detailed settings Reject everything