South Korea continues to set the global benchmark for advanced mobile connectivity, and the latest controlled benchmarking from RootMetrics shows LG U+ has emerged as the country’s most reliable mobile network provider, outperforming rivals in speed, responsiveness and voice performance.
@ SamFW
The findings arrive as regulators accelerate the transition toward 5G Standalone and future 6G leadership, making network reliability the next major battleground for telecom operators.
LG U+ tops reliability rankings in independent testing
RootMetrics conducted large-scale testing between July and September 2025 across major metropolitan areas including Seoul, Incheon, Daejeon, Gwangju, Daegu and Busan. The testing combined indoor and outdoor walk and drive routes, collecting more than 63,000 real-world performance samples.
The results highlight the intense competitiveness of the South Korean telecom market:
LG U+ achieved a Reliability Score of 998 out of 1000
SK Telecom scored 997
KT scored 992
All three operators exceeded 99.7 percent success rates for completing data tasks, reinforcing South Korea’s reputation for world-leading network quality.
LG U+ also recorded the fastest median download and upload speeds in the highly urbanized Seoul and Incheon region.
Voice performance becomes the key differentiator
While overall network reliability is extremely high across operators, voice performance helped LG U+ secure the top position.
Key voice metrics from testing include:
Call setup time: 0.77 seconds for LG U+
SK Telecom: 0.98 seconds
KT: 1.32 seconds
Call block rate: 0 percent for both LG U+ and SK Telecom
This performance edge demonstrates how reliability is becoming as important as speed in mature 5G markets.
South Korea shifts focus from speed to reliability
South Korea has long been known for ultra-fast mobile speeds. However, the market is now evolving as consumers and enterprises demand consistent, uninterrupted connectivity for digital services.
The role of mobile networks is expanding to support:
Mobile gaming and immersive digital services
Digital wallets such as Samsung Pay and Naver Pay
Blockchain-based mobile driver’s licenses
Government digital transformation initiatives
As a result, network stability is increasingly viewed as a critical public service and national infrastructure.
Government mandates accelerate 5G Standalone rollout
The regulatory push from the Ministry of Science and ICT is set to reshape operator investment priorities.
Key policy measures include:
Mandatory deployment of 5G Standalone (SA) by 2026
Spectrum reallocation tied to the 3.5 GHz band, expiring in 2028
Incentives for deploying 20,000 additional indoor 5G base stations
Spectrum fee discounts to improve indoor coverage and reliability
These policies aim to strengthen South Korea’s leadership in 5G Advanced and future 6G technologies.
5G Standalone brings gradual performance gains
The transition to 5G SA is expected to deliver long-term improvements in user experience. Evidence from testing shows SA networks improve video start times and overall service consistency.
However, results also reveal an important nuance: optimized 5G Non-Standalone networks from LG U+ still outperform early SA deployments in raw reaction times. This suggests further optimization of Voice over New Radio (VoNR) will be required before SA fully surpasses existing VoLTE performance.
Reliability becomes the new telecom premium
With 5G speeds already reaching a high plateau, telecom competition in South Korea is entering a new phase where reliability becomes the primary differentiator.
RootMetrics testing confirms that when users initiate tasks such as calls, uploads or downloads, the key question is no longer how fast networks are, but how consistently tasks complete without failure.
BABURAJAN KIZHAKEDATH