Strengthening LTE foundation to maximise 5G potential

Partner content: The pace of 5G deployments accelerated in 2020 and the ecosystem is maturing rapidly, with 140 commercial 5G networks deployed in 59 countries. More than 800,000 5G sites have been rolled out worldwide, and the price of compatible handsets has dropped to as low as $350. 

Data from GSMA Intelligence forecasts in four or five years 5G will account for as much of half of total mobile connections, which means LTE networks will continue to support the majority of data traffic in many countries for at least another decade as it remains the underlying pillar for the user experience. 

For nations yet to roll out 5G, LTE coverage will be even more important, since it is the foundation for mobile broadband connectivity. 

These were some of the key takeaways from speakers at the Wireless Foundation Summit held at MWC Shanghai 2021, who discussed how to build the wireless foundation network of the future, which has to be powerful, simple and efficient to support a profitable business for mobile operators. 

5G corner stone 
Mohamed Madkour, Huawei’s VP for Global Wireless Networks Marketing and Solutions, said that while the industry is firmly in the 5G era as the numbers from China demonstrate, depending on what spectrum you have, how advanced your infrastructure is and how developed your market is, there has to be different strategic paths to reach the target network. 

The consensus is every country and every operator should be eyeing 5G right now. But while that is happening, he said much of the data will still be carried by 4G, which should be considered as a universal technology for everyone. 

He explained the key driver for LTE is the overall ecosystem, with prices of handsets falling to as low as $15 and the high efficiency of the technology itself that will make it the main technology for mobile broadband for years to come. 

There is no doubt 4G connections are still expanding. With LTE technology certain to be around for a very long time, 4G will continue to do the heavy lifting as data usage keeps growing, he said. 

“Every investment in 4G is an investment in 5G as well. And what matters is how overall we put 4G and 5G together in a coordination manner, so that we can benefit the experience.” 

Madkour noted that LTE and New Radio (NR) collaboration includes Smart Anchor, which can intelligently select anchors to increase the 5G activation rate up to 100 per cent. In addition, E-UTRA-NR dual connectivity (EN-DC) can significantly improve the 5G user experience, especially for users in 5G cell edge area, while dynamic spectrum sharing (DSS) can share spectrum between LTE and NR to meet fast 5G deployment and LTE traffic growth requirements. 

Capacity evolution 
Farooq Raza Khan, Head of Network Planning Department at CMPak (Zong), said operators in the country face extremely high spectrum costs, spending around 10 per cent of revenue on spectrum, which is one of the factors slowing mobile broadband development in Pakistan. 

Despite many obstacles, over the past two years, 4G penetration increased three times from 23 per cent to 65 per cent, which he noted indicates the high demand for data in the country. Over the same period, its traffic jumped almost 200 per cent, with the number of high-usage sites rising rapidly and requiring immediate capacity expansions to maintain the user experience. 

Adding to its challenges is the difficulty in upgrading equipment on shared sites due to tower space limitations. 

To meet the rapid LTE traffic growth and its specific requirements resulting from more than a third of its sites built on shared tower, the operator opted for Huawei’s FDD Smart 8T8R solution, which includes 1800MHz and 2100MHz dual-band 8T8R RRUs and software defined antennas. This improved the customer experience and expanded LTE cell capacity using twin beams, enabling dynamic beamforming for more gain after upgrading to NR. 

In 2018, TIM Brasil faced a spectrum gap compared with its two main competitors, which restricted the data speeds it could deliver to customers. 

Leonardo Capdeville, CTIO at TIM Brasil, explained that simply adding more base stations was not an option as it’s expensive to acquire new sites and the country has strict requirements limiting the number in cities. 

After the major deployment of a Massive MIMO solution, the operator was able to improve the capacity at sites by three to five times. 

TIM has deployed Massive MIMO in 200 cities. Capdeville believes that deployment is also very important for the future, because when 5G is launched, the 5G spectrum can be aggregated with lower bands, which will allow TIM to have the best mobile network in Brazil. 

Improved coverage 
China Telecom plans to expand 5G service using the 2.1GHz band re-farmed from LTE to improve suburban and rural coverage and mmWave spectrum for urban applications. 

Chief Expert at China Telecom Qi Bi said the use of low-frequency bands could allow superior coverage for all applications, including voice and IoT, while high-frequency bands could use Massive MIMO technology for more capacity. 

The operator’s LTE network on the 800MHz band has more than 400,000 sites, which Qi said greatly facilitated the delivery of NB-IoT and VoLTE services nationwide. The company upgraded its NB-IoT network to R14 in 2020 to improve capacity and throughput. 

“As a result, we saw a 100 per cent growth rate from 2019 to 2020. Currently, China Telecom has the largest number of NB-IoT connections worldwide, with more than 80 million connections supporting a rich set of NB-IoT applications,” Qi said. 

The operator also encouraged vendors to provide VoLTE default-on software on handsets, which resulted to upgrading more than 200 handset models within six months. To further drive 2G and 3G to VoLTE migration, the company helped launch low-priced VoLTE feature phones. With these efforts, it achieved 200 million VoLTE users in two years. 

Meanwhile, AIS in Thailand expanded its LTE network using the 900MHz band from 5MHz to 10MHz, with an eye to improving the voice experience. 

Wasit Wattanasap, Head of the Nationwide Operation and Support Department at AIS, said VoLTE is the foundation of 5G voice service, which is “the reason why VoLTE is quite important to us”. 

He noted the main benefit of VoLTE is it increases handset battery life by about 40 per cent and it also speeds up call setup time. “Other services that can be added at a later phase include RCS or other multimedia services,” said Wasit. 

Low-band coverage is essential to the migration of legacy services to LTE. However, low-bands are narrow, and with many users preferring its better coverage compared with mid-bands, congestion can occur, resulting in a poor user experience, especially for cell edge users. In Madkour’s presentation, he recommended using the low-band 4T4R+SingleCell solution to enhance low-band experience. 

“SingleCell schedules user traffic in the middle of the cell to mid-bands and lets low-bands focus on serving cell edge users. By doing this all the bands would be scheduled as one cell, and the specialty of mid-bands and low-bands can be fully exploited,” said Madkour, who noted low-band 4T4R+SingleCell can bring average user experience gains in low-bands of 50 per cent to 80 per cent. 

Moving to LTE 
Sebastien Codeville, CEO of KaiOS Technologies, highlighted that roughly 2 billion people still use 2G feature phones, suggesting “affordable internet-enabled phones are needed to fully migrate these 2G users to 4G”. 

He explained that while some people are not connected to the internet by choice because they want to use a simple device, most are not connected because they cannot afford an internet-capable device. 

Codeville cited GSMA data finding that to own a smartphone you need to be have income of at least $10 a day. In emerging markets, the affordability of the device is the main issue. 

“A new category of feature phones solves this piece of the puzzle. It provides internet access for the next billion at an affordable price, while facilitating 4G or even 5G migration.” 

Smart feature phones run on KaiOS and support LTE networks with access to KaiStore, which hosts more than 900 popular and essential apps, allowing users to benefit from valuable digital content and connect with friends and family, he said. 

After three years of working with Reliance Jio in India, about 26 per cent of the operator’s subscribers use a KaiOS-enabled device.