In the Age of 5G, LTE Remains an Important Anchor

ABI Research forecasts Long-Term Evolution (LTE) to generate the most data traffic globally up until 2025, at which point 5G will overtake by 2026 (LTE and 5G combined will generate 1,600 exabytes of mobile data globally by 2026). As such, LTE still remains responsible for the majority of the data traffic for the next five years and will still be an essential technology to enable Mobile Broadband (MBB) in emerging markets. For developed markets, an extensive LTE network is foundational as an anchor for 5G Nonstandalone (NSA), and higher LTE coverage can serve rural areas and improve the initial user experience for 5G as users will experience LTE and 5G concurrently on the same spectrum through dynamic spectrum sharing, in which areas with limited 5G coverage will switch to LTE to ensure a consistent flow of data traffic.

To accommodate LTE’s data traffic, there is a need to optimize spectrum capacity and efficiency. Most LTE access spectrum is deployed in the sub-6 GHz band (which includes both low band and mid-band)—a well occupied spectrum due to its narrow bands and high coverage—therefore making spectral efficiency very important.

Huawei’s innovations in its LTE business solutions serves to meet these demands and are geared toward increasing coverage, capacity, and user experience. Some of these latest hardware innovations include the tri-band Remote Radio Unit (RRU) 5512 that can accommodate three different low bands (700 MHz, 800 MHz, and 900 MHz), resulting in a 67% workload reduction and rental fee savings as only one RRU box (instead of three) needs to be deployed. There are also software innovations such as SingleCell technology that improves coverage by using technology to schedule switches between mid-band for users nearer to the cell site and low band for users farther from the cell site to improve coverage and user experience. SingleCell technology increases average throughput gain for LTE by 50% to 80%. Both these solutions serve to increase coverage while being cost-efficient and are beneficial to both emerging and developed markets. For emerging markets, this can extend LTE coverage and thus MBB services into rural areas or deeper for suburban areas while also creating the necessary LTE rollout that will be foundational for 5G NSA.

For developed markets, LTE helps to support NSA 5G. NSA 5G will still require LTE infrastructure assets such as the LTE Evolved Packet Core (EPC) and base stations as the User Equipment (UE) will dynamically switch between LTE and 5G to provide the best 5G coverage. The 5G NSA rollout is predicated on reaching higher 5G coverage much more efficiently because it will help ease capital expenditure for operators by reducing the number of new 5G cell sites that will need to be deployed. As such, LTE remains a crucial anchor for 5G NSA deployments, especially for operators in developed markets with an extensive LTE rollout that can serve as a springboard for bringing 5G NSA to the market. LTE can provide a better user experience and coverage for 5G NSA and provide a faster time-to-market for operators deploying 5G NSA while leveraging their LTE investments.

Operators need to protect their LTE investments in the era of 5G by making more efficient use of their assets, such as network equipment and owned spectrum. For one, operators need to focus on service migration where an LTE core is capable of upgrading to 5G through a software upgrade and rollout of 5G in a cost-efficient manner. While it is possible to introduce 5G Standalone (SA) through deployment of greenfield 5G cores, this would be extremely costly and might not be feasible as an aggressive rollout of the 5G SA device ecosystem and chipsets has not been fully matured yet. A useful straight-to-5G SA deployment would be for private networks (or public networks with network slicing) for enterprise usage where 5G SA functionalities such network slicing and ultra-reliable low latency communication are important for mission-critical applications such as wireless emergency stops in factories and remote crane control at ports.

For a more conservative approach, operators should first introduce 5G New Radio (NR) through an NSA core that can support both LTE and 5G NSA. Using an EPC to support dual connectivity for 5G and LTE is known as the Option 3X NSA architecture. This approach is suitable for markets that already have a decent penetration rate of UE that can support 5G NSA. This can be achieved with dual-core networks that are provided by network equipment vendors. An example of such an offering is Ericsson’s Dual-Mode 5G Cloud Core solution that combines the EPC and the 5G core that allows operators to transition from LTE to 5G NSA and then eventually 5G SA.

Interworking between the EPC and 5G core will be essential to support hand-overs between the two cores, to maintain service continuity, and to support the full benefits of 5G’s service-based architecture. As such, ABI Research believes that it will be most cost-efficient to transition to a full 5G core for SA, which will drive the full set of 5G capabilities such as network slicing and cloud-native services. Interworking should be achieved with EPC so that LTE UE can continued to be used on the network. This option would allow for a much more rapid evolution to 5G core for operators as compared with moving to the Option 7X architecture where the 5G core supports both 5G NR and LTE. This is because Option 7X, while ensuring a tight interworking for LTE and 5G at the Radio Access Network (RAN) level, will require significant investment for reconfiguration of the transport network and upgrade of the RAN software to eventually support full 5G SA services.