PARTNER FEATURE: A recent review shows that, while discussed less in comparison to trending technologies, including 5G, artificial intelligence (AI), and cloud, Voice over LTE (VoLTE) has played a significant role during lockdown.

Recently, common users have to rely increasingly on voice calls to keep in contact with their friends and family members, as well as colleagues. Enterprises also turn to voice services as a supplement to their video conference services. VoLTE boasts high quality voice services and enjoys a robust network guarantee, making it the optimal choice to fulfill these purposes.

Compared with 2G and 3G voice services, VoLTE’s advantages are obvious. It provides high definition (HD) experience and faster call connections. It also supports concurrent data and voice services, enabling users to make calls without having data services interrupted.

The excellent performance of VoLTE has consolidated the common understanding among global operators that building ubiquitous VoLTE networks will be a “lifeline” project to ensure voice services. This highlights the urgency of improving VoLTE coverage and the penetration rate.

Global Insights: Voice Calls and Data Traffic Sharply Increase Amid Pandemic

First reported at the beginning of 2020, the new coronavirus has already evolved into a global pandemic, inflicting significant losses upon people globally.

This pandemic has also dramatically flipped the way how we live, learn, and work. People across the globe have been stuck indoors, shunning away from crowded places, including office buildings in central business districts (CBDs) and school campuses. The sudden shift from physical contact to remote association leads to a variety of challenges. For telecommunication, this causes an unusual rise in voice calls as they are a more preferred alternative to boost communication and stay in touch.

Therefore, it is understandable that all regions have witnessed an abrupt level of voice call traffic growth. In Italy, Spain, and other European countries, voice call traffic increased by 20% to 30%. Based on Comcast statistics, voice and video traffic over its networks increased by 212% in the U.S.

Mobile World Live also reports that the confinement, as a result of the COVID-19 outbreak, has triggered people worldwide to adapt back to traditional voice communication services. The U.S. operators AT&T, Verizon, and Sprint have all disclosed a 10% to 44% surge in voice calls.

For example, Verizon has witnessed a 10% increase in voice call traffic and 15% increase in total call durations in a single week from March 12 to 19, 2020. “For years we’ve seen a steady decline in the amount of time people spend talking to one another, especially on wireless devices,” said Kyle Malady, chief technology officer at Verizon. “The move to staying at home has reignited people’s hunger to stay connected, voice-to-voice.”

VoLTE Enhances Voice Services in Comparison to 2G and 3G

Emergency call is important in our society today. Compared with over the top (OTT) services, voice call provided by operators is of a higher quality. Anytime, anywhere voice calling means a swift exchange of information, which is crucial for when making emergency calls.

Currently, voice calls are implemented on 2G, 3G, 4G, and 5G networks. Comparatively, voice calls over 4G networks, also known as VoLTE, are more mature than 5G and more advanced than 2G and 3G. VoLTE advantages are as formidable as ever.

Higher definition: VoLTE adopts enhanced voice services (EVS) algorithms, supporting a voice rate of up to 20 kHz, far exceeding 7 kHz of previous generations. This improves the quality of high-pitched sounds, ensuring an overall higher quality of voice services.

Data concurrency: VoLTE supports concurrent voice and data services, meaning users do not have to suspend data services, including game play, while talking on mobile phones.

Faster connection: VoLTE reduces connection time to between only one to three seconds, enabling users to enjoy an almost zero-waiting experience in setting up calls.

Video talk: VoLTE further supports high-quality video services, making communication efficient and convenient.

With 5G still in its infancy, voice over NR (VoNR) is still not fully developed in terms of both technology and ecosystem to a level where its potential can be fully explored. It is easy to see that 5G users must depend on VoLTE for voice services over the coming three to five years.

Therefore, VoLTE will be essential to provide voice services for 5G networks and take over 2G and 3G networks as they become obsolete. We believe in the importance and necessity of operators in accelerating VoLTE construction and improving its coverage. VoLTE investment will continue to pay off for an extended period of time even if 5G has arrived.

VoLTE Accelerates Exit of 2G and 3G Networks to Save Energy and Reduce Cost

To date, target wireless network architecture has been determined in terms of standards and network services. 4G and 5G will continue to coexist for quite a long time. 2G and 3G services will be migrated to 4G to promote 2G and 3G sunset and spectrum refarming.

The surge of scaled 2G and 3G phase-out has already kick-started in the industry. With 4G reaching mobile users around the world, more than 100 2G and 3G networks have already or are being phased out for simplifying networks and increasing return on investment.

Experimentally, user migration constitutes the most challenging element for phasing out 2G and 3G networks. Shutting them down will not be completed overnight. Rather, it requires adequate preparations from global operators.

Encouragingly, VoLTE has already reached above 70% of global 4G networks, and 98% of post-2018 new mobile phones are VoLTE capable. In addition, VoLTE mobile phones priced at approximately USD 15 to 20 are already available in the market.

The mature ecosystem from VoLTE access networks, core networks, and terminals has enabled operators to achieve remarkable achievements in VoLTE deployment. For example, more than 50% of voice calls are running over VoLTE for China’s three largest operators. This means that VoLTE has become a major contributor to implementing mobile voice services in China.

China Mobile has been attaching great importance to VoLTE. Since 2015, it has been prioritizing investment towards VoLTE to promote its maturity and deployment. This helps consolidate its leading position in the market. By the end of 2019, it had developed 521 million registered VoLTE users. In the city of Hangzhou, nearly 80% of voice calls have been made by VoLTE users.

China Mobile has also successfully developed innovative applications to take advantage of the full potential of VoLTE. For example, China Mobile Zhejiang provides a video conference system based on VoLTE video for mobile phones. Assisted by cloud-network synergy, this system enables users to initiate and join conferences with simple touches on mobile phones.

China Telecom and China Unicom have made no exception in their VoLTE development over the past two years. Corporate-level strategies are implemented, touching upon networks, business, and marketing, to vigorously drive forward VoLTE growth. In 2018, China Telecom announced its decision to deploy VoLTE as the default voice solution, with a further move proposed in 2019 to call for the industry to develop VoLTE mobile phones priced as low as USD 15.

The experience and strategies attributing to the VoLTE success of China Telecom are a valuable reference to other global operators. These include building nationwide LTE networks, terminating the support for 2G (CDMA) on 5G terminals, and working with industry partners to provide affordable VoLTE phones and promote VoLTE as the default voice solution.

Moving forward, there are still challenges to further expand VoLTE. LTE network coverage must be increased to prevent voice services from falling back to 2G and 3G networks. Operators must improve VoLTE penetration rate by promoting VoLTE to be turned on by default and also as a standard configuration for mobile terminals.

In conclusion, VoLTE is a “lifeline” of voice communication, particularly in case of a pandemic crisis. The exploration and practice of VoLTE in China and other countries is valuable reference for global operators. VoLTE will reach global users in the near future.

Huang Haifeng