LTE will continue to underpin the mobile broadband experience even as the industry pivots to 5G, helping operators migrate from 2G and 3G, offer services such as VoLTE and NB-IoT and run more efficient networks.

During the MBB Foundation Summit at Huawei’s Global MBB Forum this year, operators were keen to point out that LTE has played a key role during the coronavirus pandemic and its quality of service and ubiquitous coverage mean it will serve as an important counterpart to 5G in the years ahead.

Understandably in a year when the number of 5G commercial launches has accelerated, the focus has been on next generation connectivity as the likes of Apple announced its own compatible iPhone.

However, there is still a considerable growth opportunity for 4G LTE. According to the recent GSMA State of Mobile Internet Connectivity report, published in September 2020, 4G accounts for more than half of global mobile connections but there are 3.4 billion people who live in areas with data coverage but who do not use mobile internet.

Opening the session, Huawei’s Yang Chaobin said global mobile broadband development continues to be uneven, pointing to China and South Korea, where 4G accounts for more than 80% of connections, and Latin America, where this figure is only 47%.

He said a successful 4G network will have the knock-on effect on an operator’s 5G plans as it will have advantages in terms of site location, spectrum acquisition and access to fibre. He added: “4G is still the basic MBB network in many countries for a long time…The LTE network will become the basic network for voice, IoT and data services in the 5G era.”

To support this, he said operators need to migrate their networks from 2G and 3G to LTE services. Deutsche Telekom was the most recent high profile operator to set an end date for 3G. It plans to turn off the network in the summer of 2021. Chaobin said: “The LTE network is complete and the ecosystem is mature. The time has come to replace the 2G/3G network.”

LTE is the mobile broadband foundation
Henry Calvert, head of future networks at GSMA, agreed and said by the end of this year 54 operators will have closed down their 2G and 3G networks. By 2025 a further 78 operators will have done so.

Calvert outlined how LTE has been playing a crucial role in supporting people and businesses during the coronavirus pandemic. He said capacity growth and network traffic has grown by more than 20% in some markets as people turn to mobile networks for home working and home schooling. This would not have happened if it wasn’t for LTE’s maturity and associated technologies such as carrier aggregation, he reflected. “The world came together and [unlimited data] zero-rated plans seemed to be fairly ubiquitous to allow people to get along with their work. But most importantly, education seems to be one of the major drivers for usage at home.”

Calvert is confident operators are working to connect this untapped market of 3.4 billion unconnected people, especially given there is only a coverage gap of seven percent. The GSMA predicts by 2025 4G will reach 56% penetration worldwide.

In a separate presentation, Mohamed Madkour, Huawei’s vice president of global wireless marketing and solutions, said LTE was the foundation for a successful 5G network and without it, it would be impossible to guarantee quality of service in future. He said every dollar invested in 4G is also an investment in 5G. Technology such as fixed wireless access, voice over LTE and the Internet of Things were innovations of the 4G generation that will endure through 5G’s lifetime.

He said: “[4G] is the foundation when it comes to the traffic. It is the foundation when it comes to services. But it also is the foundation to have great 5G. Remember, a great 5G can only be cultivated on a good soil of 4G. They are naturally decoupled together. You cannot put 5G in a room where you don’t have 4G. How would you know? How is it going to make perfect business sense? It will not.”

Low band coverage boosts service development
Shen Shaoai, adviser to the technology innovation department at China Telecom, showed just how quickly demand for 2G and 3G was declining. At China Telecom, 3G data usage has halved in just over nine months and voice over LTE traffic has exceeded the volume of 2G calls.

She said 2G and 3G shutdown will be driven by the need to free up the “golden spectrum” of lower frequency bands that will give deeper coverage. But she stressed this will be used as much for 4G as it will for 5G. She said: “If these lower frequency bands are refarmed to 4G and 5G networks, wide and deep coverage can be achieved with fewer base stations thus reducing the total cost of network investment and operations, as well as VoLTE and NB-IoT development can be boosted.”

Carlos Bardon, director of network planning at Telecom Argentina, also emphasised the high quality of a successfully rolled out 4G service. He said: “As a telco it starts with the network and we ensure the best possible future proof network is in place. In the upcoming 5G era, an LTE network with coverage and quality is must.”

He was an advocate of low-band 4T4R, saying that the operator was using it alongside Massive MIMO to deliver high coverage and high quality without making its network overly complex. It is using 4T4R at the 700MHz band and plans to roll out dual band 4T4R in 2021 for the 700MHz and 850MHz bands. Massive MIMO will be used in highly congested areas at a high capacity frequency. He added: “We believe that all of these bring us a highly-cost efficient LTE network and also better coverage. This has allowed us to ramp up 5G deployment next year.”

He said Covid-19 has changed how people have used their mobile phones. “People tend to watch higher resolution videos for study, social, entertainment, etc, he said. The shift to indoor usage has required low band frequency spectrum, which has better propagation. It was necessary that operators further explore the likes of carrier aggregation and massive-MIMO in order to meet the demands of users.”

Smart ways of sweating assets
In addition to the existing and forthcoming technology benefits of LTE, operators speaking elsewhere in the forum were keen to highlight the financial advantages of continuing to manage a high performance 4G network. Andrey Kuzin, CTO at Cambodian operator Smart, said: “We have to find ways to sweat our assets better to improve our capex efficiency.”

He added that the cost benefits of using 4G in the 5G era were as important as its user experience advantages. In a separate presentation, Nassir Jama, wireless director at Zain, said 4G continued to offer “high throughput, high speed and very accessible latency” and said this was crucial for when a user is handed over from 5G.

Delegates also heard how there was innovation still to come with 4G technology. MTS’ Director of RAN said the Russian operator has deployed Huawei’s smart 8T8R solution in Moscow. He said the technology, which offers twice as much throughput gain and capacity compared to 4T4R solutions, means that it can better manage traffic, offering greater capacity, higher download speeds and an overall improved user experience.

4G is the best choice for universal connectivity
Ken Ayers, Director for the Emerging Device Strategies at Strategy Analytics, said the industry needed to come together to open up 4G to low income consumers. He highlighted cooperation between operators, handset manufacturers and smartphone manufacturers in some markets, giving the examples of Indonesia and Thailand, where the partnerships were helping to open up services to previously unconnected subscribers. He predicted more operators will follow those markets’ leads in future as giving consumers access to cheap smartphones today will serve as a runway to 5G networks tomorrow.

He also leant his voice to fellow speakers who were calling for operators to switch off their 2G and 3G networks. added: “Transitioning from sunsetting 2G and 3G networks in transition to 4G offers clear benefits. They’re financial, they’re spectral, reducing opex and creating new revenue opportunities via new devices and different devices that simply were not available in 2G.”

Concluding the forum, Li Nan from industry group GTI, which built the TD-LTE ecosystem, said ubiquitous connectivity is a key contributor to the United Nations’ Sustainable Development goals. “Broadband can help people achieve good health and well-being and good quality education, decent work and the economy will [then] increase.”

Because of the maturity of 4G, he said that operators can achieve strong revenue growth with relatively little investment. He outlined how LTE traffic has surpassed that of desktop and laptop PCs. More crucially than that, he added: “Due to its high affordability and high availability, mobile broadband is the first choice [for many] to access the digital world. It may be the best choice and only choice for low income users.”

However, he warned that more needed to be done to overcome the obstacles to successful widespread 4G deployment, which will be the subject of a forthcoming white paper from GTI. Access to the right kind of spectrum, sites for infrastructure, backhaul were all highlighted as challenges. In contrast to other speakers, GTI’s Nan said that while smartphone prices are falling, they are still an issue for those on low-incomes. More needed to be done to overcome digital illiteracy in some markets, he warned, as many people still lack the confidence and skills to use the mobile internet effectively.

In order to solve these problems, he said governments need to do more to give operators access to low frequency spectrum as well as sites for infrastructure and foster a universal broadband policy. Additionally, manufacturers should further lower the price of entry level phones while operators need to refarm their 2G and 3G spectrum to LTE to meet demand for mobile connectivity.

He concluded: “When we finish all of these things, I think we can have a bright future in the worldwide deployment of 4G.”