The three mobile carriers' 5G quality competition is expected to shift from a download-speed focus to a contest over network stability. The government is preparing new quality evaluation indicators in line with the nationwide introduction of 5G standalone mode (SA) service in December. Beyond simple data transmission speeds, key evaluation factors are expected to include how stably 5G connections are maintained and whether differentiated services can be provided.

The Ministry of Science and ICT and the telecom industry said on Oct. 20 that the ministry will develop quality evaluation indicators reflecting 5G SA specialized functions within the year and push ahead with pilot measurements by year-end. New evaluation items are expected to include whether SA connections can be established and maintained, latency and network slicing quality.

Speed-focused assessments have limits; authorities will also examine 5G standalone performance.

In August, the ministry launched a public-private consultative body to promote telecom network investment in the AI era, with participation from the three carriers and related agencies, and reviewed the status of the carriers' push to commercialise nationwide SA service. The ministry also decided to set up an evaluation system tailored to 5G SA commercialisation. Until now, telecom service quality evaluations have measured download and upload speeds, connection success rates, latency and the rate of switching to LTE. In competition among operators, download speed has been the most watched indicator.

The industry, however, has raised criticism that after switching to 5G SA it is difficult to evaluate network performance based on speed alone. Unlike non-standalone mode (NSA), which also uses an LTE core network, 5G SA is configured with 5G for both the radio network and the core network. The need for indicators suited to 5G-specific functions such as ultra-low-latency communications and network slicing, which faced constraints in the existing NSA environment, has been raised.

Similar criticism has recently been raised in the National Assembly. Kim Nam-kuk (김남국), a lawmaker from the Democratic Party and a member of the National Assembly's Science, ICT, Broadcasting and Communications Committee, stressed that the annual telecom quality evaluation system should be strengthened with a focus on quality of experience (QoE).

There was also a gap between average download speeds and users' perceived quality in the existing evaluations. In last year's ministry evaluation results, the nationwide average 5G download speed was 973.55 Mbps. By carrier, KT was the fastest at 1,030.26 Mbps, followed by SK Telecom at 1,024.50 Mbps and LG Uplus at 865.88 Mbps.

The rankings changed in the service-by-service required-speed fulfilment rate that reflects users' perceived quality. Based on high-definition streaming, which requires speeds of 100 Mbps or more, SK Telecom was the highest at 98.39 percent, followed by LG Uplus at 98.28 percent and KT at 97.88 percent. This means download speed does not necessarily guarantee stability in actual services.

An industry official said, "The operator with the fastest download speed does not guarantee the highest quality in all service environments." The official added, "It is true that new evaluation standards tailored to 5G SA were needed."

Connection stability, latency and slicing are emerging as new quality indicators.

The ministry has been supplementing the limitations of the existing evaluation since last year. It introduced simultaneous measurement of 5G and LTE, and reflected new indicators such as required-speed fulfilment rates by service, including web searches, video conferencing and high-definition streaming.

The industry expects that, in addition, performance in SA access and retention will become key items in the future 5G evaluation system. Measuring "latency" to check how quickly the network responds to data transmission requests is also cited as a major evaluation factor.

The ministry is developing indicators and measurement methods reflecting 5G SA characteristics through a research group involving experts from industry, academia and research institutes. It aims to conduct pilot measurements by the end of the year based on this work. A ministry official said, "We are currently developing quality evaluation indicators tailored to 5G SA." The official added, "However, as there are differences in the level of 5G SA deployment by carrier, whether to disclose evaluation results requires further review."

The three carriers are also working to find new services in line with the SA transition. KT started SA commercial service in July 2021 and is expanding its scope of application. SK Telecom and LG Uplus are carrying out core network expansion and device interoperability verification, aiming to provide nationwide service by the end of the year.

The industry is also calling for standardised measurement environments suited to the new setting. An official at one carrier said, "In particular, network slicing has different quality levels required by each service, making it difficult to apply uniform comparison criteria." The official added, "Corrective indicators must also be prepared to prevent distortion where results vary depending on the location of the measurement server, network configuration and measurement environment."