As Taiwan High Speed Rail ridership continues to rise, average monthly passenger trips in 2025 have reached about 6.83 million. The Consumers’ Foundation recently released an outsourced field test of 5G networks along the entire THSR line, revealing that all three telecom operators have insufficient 5G signal coverage that urgently needs improvement. Taiwan High Speed Rail said it has partnered with the three major telecom operators on signal improvement works along the route and expects to fully enhance call and internet quality along the line by the end of 2027.
What are the latest 5G field test results along the high-speed rail line announced by the Consumers’ Foundation? What improvement plans does Taiwan High Speed Rail have? Here is a summary and explanation:

1. The Consumers’ Foundation releases the latest results of 5G field tests along the high-speed rail line:

Taiwan High Speed Rail ridership has continued to climb, reaching an average of 227,000 passengers per day in 2025. To understand the actual performance of 5G services along the THSR corridor, the Consumers’ Foundation commissioned the Telecom Technology Center (TTC) to conduct on-site 5G network tests across the entire Taiwan High Speed Rail line on March 18, 2026. The tests covered the entire THSR line and were carried out during off-peak weekday hours, using alternating tests on express trains and trains stopping at every station.
According to test results released by the Consumers’ Foundation, the three major telecom operators were able to use 5G services most of the time along the high-speed rail route, but on certain sections, only 4G was available, some areas still had insufficient signal coverage, and there were even failed call connections and dropped calls. The actual test results for each operator along the high-speed rail route are as follows:

A. Average 5G download speed:
The three major carriers performed as follows: Chunghwa Telecom 159Mbps, Taiwan Mobile 144.65 Mbps, and Far EasTone Telecommunications 122.27 Mbps. Chunghwa Telecom’s download speed of >150Mbps earned a “Strong” rating, while Taiwan Mobile and Far EasTone Telecommunications, with download speeds between 100 and 150 Mbps, were rated “Good.”
Overall, underground stations in the north (such as Taipei, Banqiao, and Nangang) show better download speeds due to well-developed infrastructure; in the central and southern regions, all three operators achieve relatively high download rates on the Chiayi section. However, in tunnel sections such as Hsinchu and Miaoli, affected by terrain, all three operators show speed fluctuations, and download rates are less stable.

B. Average 5G upload speed:
The three major carriers performed as follows: Chunghwa Telecom 39.21 Mbps, Taiwan Mobile 31.19 Mbps, and Far EasTone Telecommunications 36.01 Mbps. All three telecom operators’ upload speeds were >30 Mbps, earning a “Good” rating.
Overall, underground stations in northern Taiwan (such as Taipei, Banqiao, and Nangang) showed better upload speeds due to well-developed infrastructure; in the central and southern regions, all three operators achieved higher upload rates on the Kaohsiung section. On tunnel sections in Hsinchu and Miaoli, affected by terrain, all three operators showed speed fluctuations, and upload rates were less stable.

C. 5G Availability and Coverage (Signal Strength):
The 5G availability test results were 92.86% for Chunghwa Telecom, 90.22% for Taiwan Mobile, and 85.31% for Far EasTone Telecommunications. Chunghwa Telecom performed the best, while Far EasTone Telecommunications performed slightly worse.
The three major telecom operators can provide 5G service along most of the high-speed rail route most of the time, but in certain sections, such as Yongkang in Tainan and Zaoqiao in Miaoli, all three operators were found to offer only 4G, indicating that local coverage gaps still exist.

The 5G coverage test results showed that the north-south signal strength ratios measured for the three operators were identical, indicating that reception quality was relatively stable, and that 5G signal strength remained between “Fair” and “Good” most of the time. However, signal strength was still “Poor” on some road sections, indicating that there is still room for improvement in coverage.

D. Voice stability:
In voice testing, all operators showed sporadic issues, indicating that even in a 5G environment, voice service stability is not yet fully mature.
Chunghwa Telecom: 1 call drop and 1 failed call attempt (Changhua Tunnel section); Taiwan Mobile: 2 call drops (Xinshi, Tainan and Miaoli Tunnel); Far EasTone Telecommunications: 2 failed call attempts (Taoyuan and Xizhou, Changhua).

2. Taiwan High Speed Rail Improvement Plan:

Taiwan High Speed Rail has a total route length of 350 km, including 52 tunnel/underground sections with a total length of 68 km (19%). Because the high-speed rail moves at high speed, internet speeds are easily affected by the “Doppler effect” and the “handover mechanism” when mobile phones frequently switch between different base stations, resulting in problems such as discontinuous 5G coverage, signal attenuation in tunnels and specific sections, and insufficient connection stability.
Taiwan High Speed Rail stated that in March 2026 it signed a memorandum of cooperation with the three major telecom operators for the “High Speed Rail 2.0” full-line communications quality upgrade project. It has introduced an advanced mobile communications architecture and a new generation of 5G communications equipment to replace the old relay transmission model and improve communications quality for passengers riding the HSR. THSR provides sites and power, while the three major telecom operators jointly invest about NT$2 billion to fully replace the 369 “base frequency repeaters” along the HSR route with new “fiber-optic radio frequency amplifiers” (RRH), and the number of installations will increase to more than 2,200.

The “High Speed Rail 2.0” system-wide communications quality upgrade project carries out construction during the 4-hour nightly service suspension period. In February 2026, demonstration validation was completed for a 1.5 km area of the Taipei–Banqiao tunnel section, with signal strength increasing from 2 bars before testing to 5 bars. By the end of 2026, priority will be given to upgrading Nangang–Banqiao and the continuous tunnel groups along the route, including 6 sections—Nangang–Taipei, the Taipei–Banqiao underground section, Huilong–Taoyuan, Qieshui–Baoshan, Xihu–Tongxiao, and Shengang—comprising 29 tunnels (39 km) and accounting for approximately 57%.
The third phase consists of tunnel upgrades in the remaining six sections—the underground section of Taoyuan Station, Hukou, Xinmiao, Tongxiao, Zaoqiao, and Changhua—with a total of 23 tunnels (29 km), or about 43%, as well as open-track areas such as Yunlin, Chiayi, and Tainan.The project is expected to be fully completed by the end of 2027, when communication quality will be consistently stable at a five-bar level across the board, allowing passengers to directly experience a significant improvement in communication quality.
In addition to improving communications quality along the route, Taiwan High Speed Rail said it will upgrade 4G and 5G mobile communications and simultaneously promote the “Train Wi-Fi Optimization Project,” upgrading in-car communications quality across the entire fleet to Wi-Fi 6 technology and expanding back-end bandwidth to meet business and leisure travelers’ real-time connectivity needs and improve signal discontinuity and bandwidth bottlenecks during high-speed travel and in tunnels.

Source: KOCPC Chinese