How does VoLTE technology support both calling and data services? How is it different from 2G/3G?

1. What is VoLTE?

VoLTE (Voice over LTE) is a technology for making voice calls over 4G LTE networks. It allows users to make high-definition voice and video calls over 4G networks without relying on traditional 2G or 3G networks. With the introduction of VoLTE technology, users can use data services, such as surfing the Internet or using applications, while on a call without affecting call quality.

2. Advantages of VoLTE

 

VoLTE (Voice over LTE) is a voice call technology based on the LTE network, which offers many advantages, including:

1. Better Voice Quality: VoLTE adopts advanced voice coding technologies, such as AMR-WB (Adaptive Multi-Rate Wideband Coding), which can provide clearer and more natural voices, just like face-to-face communication.

2. Faster Call Setup: Compared with traditional call methods, VoLTE technology greatly shortens the call setup time. The time from dialing the number to hearing the ringback tone is significantly reduced, enabling users to communicate more quickly.

3. Concurrent Voice and Data: VoLTE technology allows users to enjoy high-speed data network services while on a call, such as looking up information online or watching videos while talking.

4. Support for High-Definition Video Calls: This provides users with a richer and more intuitive communication method. Whether sharing life moments with family and friends or having business video conferences, it can bring a better experience.

5. Improved Coverage and Connectivity: VoLTE can double the call connection speed compared to existing methods, and when there is no 4G signal, 2G and 3G connections are still available, which simply means a wider overall mobile coverage.

6. Better Battery Life: Anyone currently using 4G can find that their battery life increases with VoLTE. Without it, whenever you make or receive a call, your mobile phone has to switch from 4G to 2G or 3G because 4G calls are not supported, and then switch back again once the call is completed. All these switches, as well as the need to search for different signals each time, have a significant impact on the battery.

7. Support for Multiple Device Access: Telecom VoLTE supports simultaneous access by multiple devices, and users can seamlessly switch between devices such as mobile phones, tablets, and laptops. This brings a more convenient communication experience to users.

8. Low Latency: The voice call latency of Telecom VoLTE is less than 50 milliseconds, which is about 50% lower than that of traditional voice calls. This enables users to experience a smoother call when making voice calls.

9. High Speed: Telecom VoLTE adopts OFDM (Orthogonal Frequency Division Multiplexing) technology, which can achieve a downlink rate of 100 Mbps and an uplink rate of 50 Mbps. Compared with traditional 2G/3G networks, the speed is several times faster. This means that users can conduct data transmission while making voice calls, such as browsing web pages and watching videos.

10. Support for High-Definition Video Calls: Telecom VoLTE can not only achieve high-quality voice calls but also support high-definition video calls. This means that users can enjoy clearer and more realistic picture effects when making video calls.

3. Advantages Compared with Traditional 2G/3G Voice Calls

VoLTE (Voice over LTE) has the following advantages compared with traditional 2G/3G voice calls:

1. Higher Voice Quality: VoLTE adopts high-resolution codec technologies, such as AMR-WB (Adaptive Multi-Rate Wideband), which can provide higher voice quality than traditional 2G/3G networks, with the voice call quality improved by about 40%.
2. Lower Access Delay: VoLTE has a shorter call setup time and better user perception. Its access delay (waiting time after dialing) is 50% lower than that of 3G, approximately 2 seconds, while in the 2G era, this waiting time was 6 - 7 seconds.
3. Simultaneous Support for Data Services: VoLTE allows users to use data services while on a call, such as surfing the Internet and video calls. This means that users can freely browse web pages, check emails, and use social media while on a call without worrying that the network speed will be affected.
4. Low Drop Rate: The frequent call drops in the 2G and 3G eras have been improved with the advent of VoLTE, and the drop rate of VoLTE is close to zero.
5. High Spectral Efficiency: VoLTE uses IP bearer, which has higher spectral efficiency and helps operators increase network capacity.
6. High-Definition Video Calls: VoLTE supports high-definition video calls, which provides users with a richer and more intuitive communication method. Whether sharing life moments with family and friends or having business video conferences, it can bring a better experience.

4. Usage Conditions of VoLTE

To use VoLTE (Voice over LTE), the following conditions need to be met:

1. Mobile Phones Supporting VoLTE Function:

• Most modern smartphones support the VoLTE function, but some older or low-end devices may not. For example, Apple supports the VoLTE function on iPhone 6 and above models, while the iPhone 5s does not.
• Android phones of different brands and models also have different settings to enable the VoLTE function. For example, on Huawei phones, it can be enabled in "Settings - Wireless & Network - Mobile Network - VoLTE Call".

2. Activation of VoLTE Service:

• Users need to contact their operators to activate the VoLTE service. For example, Telecom users can send the text message "KTVOLTE" to 10001 to activate it, or log in to the Telecom online business hall or mobile business hall to activate it.
• China Unicom users can send the text message "DGVOLTE" to 10010 to activate the VoLTE service.

3. Mobile Phone Settings:

• Enable the VoLTE function in the mobile phone settings. For example, iPhone users need to upgrade the system to version IOS 13.3 or above, and then click "Settings - Cellular - Voice & Data - Click 4G, and turn on VoLTE".
• Android phone users can enable it in "Settings - Wireless & Network - Mobile Network - VoLTE High-Definition Call".

4. Network Coverage:

• The mobile phone needs to be within the coverage area of the 4G network, and the operator's network in the area supports VoLTE calls. In areas without VoLTE coverage, calls may fall back to traditional 2G/3G networks.

5. Both Parties Support VoLTE:

• The mobile phones of both parties on the call need to support and activate the VoLTE function; otherwise, they cannot enjoy the high-definition voice and video call services provided by VoLTE.

6. Tariff:

• The tariff for the VoLTE service is usually billed according to the voice calls in the user's current package, and there may be special billing policies during the trial commercial period.

5. Principle of VoLTE Technology in Improving Call Quality

VoLTE (Voice over LTE) technology improves call quality in the following aspects:

1. High-Resolution Codec Technology:

• VoLTE adopts AMR-WB (Adaptive Multi-Rate Wideband) codec technology, with a bandwidth of up to 23.85 Kbps, which is more than twice that of AMR-NB (12.2 Kbps) commonly used in 2G/3G networks.
• This high-resolution codec technology can capture a wider range of audio frequencies (50 - 7000 Hz), making voices clearer and more natural, especially better at capturing high-frequency sounds such as labiodental sounds.

2. All-IP Network Architecture:

• VoLTE is based on the 4G LTE network, which is an all-IP network architecture. Voice and data services are transmitted through the packet-switched network.
• This architecture eliminates the limitations of traditional circuit-switched networks, enabling voice calls to enjoy high-speed and stable network connections like data services, thus improving call quality.

3. Low Latency and High Reliability:

• VoLTE has a shorter call setup time, usually around 2 seconds, which is 50% lower than that of 3G networks.
• The drop rate is close to zero, thanks to the high reliability and stability of the LTE network.

4. Support for High-Definition Video Calls:

• VoLTE not only supports high-definition voice calls but also supports high-definition video calls, providing a clearer and more realistic video call experience.

5. End-to-End QoS Guarantee:

• Since it adopts IP-based communication methods, VoLTE can achieve end-to-end QoS (Quality of Service) guarantees, ensuring that the quality of voice calls is not affected by network congestion.

6. Seamless Integration with IMS:

• VoLTE relies on the IP Multimedia Subsystem (IMS) for session control and routing. IMS provides rich multimedia service support, ensuring high-quality voice and video calls.

7. Optimized Wireless Network Environment:

• To ensure high-quality calls of VoLTE, the wireless network environment needs to be optimized, including improving wireless coverage quality, reducing interference, and minimizing signal fading.

8. Efficient Signaling Process:

• The signaling process of VoLTE has been optimized to ensure fast call setup and stable call connections and reduce call setup delay.

Through the comprehensive application of these technologies, VoLTE can provide a higher-quality voice and video call experience than traditional 2G/3G networks and has become a key technology in modern mobile communication networks.

6. Differences between VoLTE and Traditional 2G/3G Voice Calls

Difference in Technical Principles: VoLTE (Voice over LTE) is an IP data transmission technology based on the 4G LTE network. It allows voice calls to be transmitted through the data network instead of relying on traditional 2G or 3G networks. In contrast, traditional 2G/3G voice calls are carried out through circuit-switched technology and require dedicated voice channels.

• Improvement in Call Quality: VoLTE provides a higher-quality voice call experience. Since VoLTE adopts high-resolution codec technologies, its voice quality can be improved by about 40% and supports a wider frequency range, making the call voices clearer and more natural.

• Enhancement of Call Stability: The call stability of VoLTE is better than that of traditional 2G/3G calls. Because VoLTE uses IP transmission technology, it can achieve lower latency and more stable connections, reducing the possibility of call interruptions.

• Reduction in Call Delay: The access delay (waiting time after dialing) of VoLTE is significantly lower than that of 2G/3G calls. The access delay of VoLTE is approximately 2 seconds, while in the 2G era, it was 6 - 7 seconds, which means that users can get through calls more quickly.

• Support for Multimedia Services: VoLTE not only supports voice calls but also supports high-definition video calls and other multimedia services, providing a richer communication experience.

• Utilization Efficiency of Network Resources: VoLTE can utilize network resources more efficiently. Since VoLTE is based on the IP network, it can simultaneously transmit data and voice on the same network, improving the utilization efficiency of the spectrum.

• Tariff Issues: The tariff model of VoLTE is similar to that of traditional 2G/3G calls. It is usually billed according to the call duration and included in the user's package. However, if you use VoLTE's video call service, you may need to pay an additional fee.

• Device Support: To use VoLTE services, you need a mobile phone that supports the 4G network, and the mobile phone must support the VoLTE function. With the development of technology, more and more mobile phone models begin to support VoLTE. Users can decide whether to activate the VoLTE service according to their mobile phone models and the service situation of their operators.

In summary, VoLTE and traditional 2G/3G voice calls have significant differences in technical principles, call quality, stability, delay, multimedia support, utilization efficiency of network resources, tariffs, and device support. VoLTE provides a more advanced and high-quality call experience.

7. Simultaneous Use of VoLTE Calls and Data Services

When using VoLTE (Voice over LTE) calls, you can indeed use data services simultaneously. VoLTE is a voice call technology based on the 4G LTE network. It allows users to continue using the data services of the 4G network during a call, which means that when using VoLTE calls, you can enjoy a high-speed network connection at the same time and seamlessly browse web pages, download files, or use other applications that require network connections.

The introduction of VoLTE technology has solved the problem that the traditional 4G network could not independently carry voice calls, enabling calls and data networks to be used simultaneously. This was impossible in the early 4G network because the 4G network at that time could only provide data services and could not carry voice calls.

To use VoLTE calls, you need to ensure that your mobile phone supports this technology and that your operator also provides VoLTE services. On devices that support the VoLTE function, users can enter the mobile phone settings interface, search for the "VoLTE" option, and then turn on the VoLTE function. After turning it on, the mobile phone will connect to the VoLTE network and allow the use of data services during a call.

It should be noted that although VoLTE provides the convenience of using calls and data services simultaneously, in some cases, such as insufficient network coverage or device compatibility issues, the normal use of this function may be affected. Therefore, when using VoLTE, users should try to choose areas with strong network signals to obtain good call quality and ensure that the device supports and has enabled the VoLTE function.

8. Application Status of VoLTE Technology

VoLTE technology has been widely applied on a global scale, and many operators have already launched services based on VoLTE. For example, China Mobile has been promoting VoLTE technology since 2014 and started its commercial use in 2018. China Telecom and China Unicom also began the commercial use of VoLTE services in 2018 and 2019 respectively.

9. Summary

By taking advantage of the high-speed data transmission capability of 4G networks, VoLTE technology has significantly improved call quality, reduced call latency, and enabled continuous data transmission during calls. These advantages have made VoLTE an important technology in the modern communication field, and it is being widely used all over the world. With the continuous progress of technology and the expansion of network coverage, it is expected that VoLTE will further enhance users' call experience in the future.