Strategy Analytics presented recently at the MBB Foundation Summit at Huawei's Global MBB Forum 2020. We spoke on "Capturing the Opportunities of 4G LTE Migration," drawing on research from our complimentary report "Low Cost 4G Handsets: Market Dynamics and Opportunities." As much of the world has its attention focused on 5G there is still significant work taking place on 4G: as a foundation for 5G networks, as an enabler for network migration away from 2G and 3G (and more efficient spectrum use), and as a major contributor to additional voice and data capacity requirements.
The speakers at this event echoed Strategy Analytics' view of 4G's key role in the mobile ecosystem. From a network perspective there are still many developments taking place to enhance the 4G experience and suitability across high-bandwidth broadband services and low-bandwidth voice and IoT, and it was encouraging to hear from a range of operators who are evolving and expanding their 4G networks to position themselves for future growth. We would highlight the following trends as central to a successful 4G network migration strategy on the path to 5G.
Firstly, LTE in low bands is needed to deliver strong coverage to facilitate the migration of voice and IoT services and to improve the indoor user experience.
The device ecosystem has evolved rapidly to support affordable 4G, with 4G smart feature phones costing as little as USD15 and 4G NB-IoT modules as low as USD3. Both the VoLTE and NB-IoT ecosystems are mature and well-established, with widespread carrier support on existing LTE networks. Work by operators needs to continue to ensure 4G can match and exceed the coverage of 2G or 3G networks, with the use of low-band obviously critical here.
- China Telecom highlighted its focus on 4G expansion into low-band spectrum (initially 800 MHz) to offer coverage for rural areas, deep urban areas and indoor, replicating the 2G coverage footprint. This has helped it to grow VoLTE subscriptions from 85 million in 2019 to 127 million (45% of its 4G users) by May 2020, and also build one of the world's most successful NB-IoT services, with subscriptions growing from 40 million in 2019 to 70 million in October 2020.
- Telecom Argentina's work to enhance indoor performance on 4G, critical as Covid-19 impacts customer mobility, has involved upgrading its 700 MHz 2T2R 4G sites to 4T4R. Next year it will be deploying dual-band 700/850 MHz 4T4R.
Secondly, 4G LTE networks need to evolve to maintain and improve the user experience as data traffic multiplies.
The majority of operators are a number of years away from peak 4G traffic levels and will need to continue to invest in the 4G network experience, ideally in a way that complements 5G deployment plans. For these operators revenue growth lags the explosion in data traffic, putting significant pressure on the "data efficiency" of network investments.
- Cambodia's leading 4G operator, Smart, has 77% of subscribers on 4G and an average data usage of 22 GB/month (compared to 9GB on 3G). It has had to rapidly evolve its 4G network to cope with the challenges of huge data loads and high levels of resource utilisation in the busy hour, and an inconsistent user experience between spectrum bands both in terms of coverage and in terms of network loading (it operates 1800, 2100 and 2600 MHz FDD and 2300 and 2600 MHz TDD). Upgrades have focused on DL 2-layer MU beamforming for 2300 MHz TDD, using B40 8T8R soft cell split solution to offer a ~30% capacity boost (compared with 8T8R), introduction of 64T64R sites offering a 3x capacity boost, and upgrading many sites to a 4T4R 6-sector (4T6S) single antenna solution to deliver improved multi-band spectrum efficiency.
- For Telecom Argentina, its response to recent data traffic growth has focused on AWS+PCS dual band massive MIMO upgrades at 2T2R sites in high traffic locations, delivering a more than 4x increase in capacity.
- In Russia, MTS has deployed FDD 8T8R RRU with software defined antenna to enable 3 and 6-sector multi-RAT operations (2T3S for 2G/3G, 4T6S for LTE, and 8T3S for 5G NR) delivering a 1.7-2x capacity gain.
Finally, 4G LTE will be a critical foundation for 5G.
4G's anchor role for non-standalone 5G is obviously is a given, a continues anchor coverage is a prerequisite for 5G coverage, beyond which it can also supplement the 5G experience with 4G-5G dual connectivity (EN-DC). For standalone 5G, 4G's importance is not at all diminished; it provides continuity of coverage and experience outside of the 5G SA footprint, and current 4G network assets are the basis for future re-farming toward 5G. Every dollar spent on 4G should be viewed as an investment in 5G, so 4G deployments need to focus on 5G-ready hardware. The initiatives above, delivering a seamless low-band coverage layer and upgrading performance and capacity with multiple antenna technologies, are key measures to optimize this foundation. 4G's role in a 5G world also involves significant efforts in 4G-5G co-ordination.
- Zain has already deployed 5G in a number of its markets in the Middle East and Africa and recognizes the need to build a stronger layer of 4G to support this. It is using 4CC aggregation across its four 4G spectrum bands (800, 1800, 2100 and 2600 MHz), together with 4T4R and 256QAM, to deliver up to 1 Gbps throughput and providing a support layer in preparation for 5G growth. "Our aim is whenever the customer goes to the 5G, to have a layer of 4G where it will provide a good experience in case of hand over from 5G to 4G."
- Telecom Argentina emphasized that sub-3 GHz spectrum was as important as C-Band for its 5G evolution. It is pursuing a multi-antenna evolution for higher spectrum efficiency and in the 5G era this will involve the use of highly integrated modules to deliver its target network of 4T4R and massive-MIMO sites.
Across all of these operators there was a clear message that a solid LTE foundation is important before entering 5G era: it helps to accelerate the use of VoLTE and NB-IoT to migrate lower-value legacy business away from 2G and 3G networks and deliver the greater efficiencies needed to succeed in 4G and 5G; helps to address 4G capacity and experience challenges to maximize network value; helps to build the foundation for future 5G networks and protect operators' investments.
— Philip Kendall, Director of the Wireless Operator Strategies Service, Strategy Analytics
This content is sponsored by Huawei.