Taiwan–Matsu No. 4 Submarine Cable and Matsu’s Microwave Stations: moda Says Completion Is Coming Soon, and the State of Matsu’s Communications Backups

On June 23, 2026, Taiwan’s Ministry of Digital Affairs (moda) issued a press release stating that the “Taiwan–Matsu No. 4” submarine cable (臺馬四號) — built by Chunghwa Telecom with Forward-looking Infrastructure subsidies — and the microwave communication systems linking Matsu’s Dongyin, Beigan, Nangan, and Juguang townships were both “coming to completion soon.” moda explained that construction of the Taiwan–Matsu No. 4 cable had been somewhat delayed by the situation in the Middle East affecting the shipping of materials, but that with Chunghwa Telecom’s continued efforts it is expected to be completed soon; once activated, there will be 3 submarine cables between Taiwan and Matsu, and Beigan, Nangan, Dongyin, and Juguang townships will each have at least 2 microwave systems for outside communication. The same press release also stated that moda Deputy Minister Ning Yeh (葉寧) traveled to Matsu’s Dongyin and Nangan townships on June 16–17, together with the speaker of the Lienchiang County Council, the head of Dongyin Township, and the Ocean Affairs Council’s Coast Guard Administration, among others, to inspect Chunghwa Telecom’s work on the Taiwan–Matsu No. 4 cable and microwave systems in Matsu, as well as improvements to mobile connectivity on the New Taima ferry (新臺馬輪) — this inspection trip took place before the press release was issued, so the two are not the same day.

This article was fact-checked on September 17, 2026, against the full text of two moda press releases, one Chunghwa Telecom cable-fault repair notice posted on its official website, and the content shown that day on moda’s “Latest Submarine Cable Status” page. This site has not tested communication quality in Matsu on the ground, and offers no advice on whether the outlying islands are suitable to visit or which telecom carrier to choose; apart from this article’s own fact-check date, every date, place, and number below can be traced to the original text of these four official documents. Where these four documents do not say something, this article notes that they do not say it, rather than inferring on their behalf or filling the gap with what media outlets or aggregator sites say.

What This Announcement Says: The Taiwan–Matsu No. 4 Cable and Matsu’s Microwave Stations

In its press release, moda places this construction within a broader policy context: through incentives such as Forward-looking Infrastructure subsidies and guidance measures, it has urged the three telecom carriers Chunghwa Telecom, FarEasTone, and Taiwan Mobile to build faster and build more, in order to strengthen mobile coverage and network resilience. moda also said it will keep encouraging carriers, under a policy of “backups upon backups,” to install diverse, heterogeneous backups such as submarine cables and microwave systems at key nodes, and will improve the resilience of outlying-island communication networks by subsidizing carriers’ equipment, refining submarine-cable early-warning systems, speeding up cable-repair mechanisms, and coordinating across agencies.

The press release also mentions a development closer to travelers’ daily lives: after moda guided carriers to make improvements, the New Taima ferry (新臺馬輪), which runs between the Matsu islands, “now has a stable mobile signal.” Deputy Minister Yeh rode the New Taima ferry from Nangan to Dongyin to test this firsthand, and officials describe it as “now able to stream video smoothly” — but that is the Deputy Minister’s own account of his experience, not measured data published by this site or by the government. As for the viewing delays crew members reported, moda explained the cause as limited bandwidth on the ship’s geostationary satellite link, which switching to a mobile network can resolve or substantially improve. moda also said that this year (2026) it is planning to subsidize carriers to extend mobile service to the shipping route between Taiwan and Matsu, but the press release gives no amount, timeline, or participating carriers.

The Complete April 2026 Dongyin Outage: How the Backups Actually Worked

An example of the backup system actually being used occurred before this announcement was issued. moda explained that on the afternoon of April 29, 2026, it received a report from Chunghwa Telecom that the Taiwan–Matsu No. 3 cable (TM3) had again suffered a fiber-core break about 2.64 kilometers off Dongyin, Matsu, causing the complete severance of the Beigan–Dongyin section; the affected area was Dongyin Township, one of Lienchiang County’s four townships, with a population of about 1,500, while Nangan, Beigan, and Juguang townships were unaffected. moda noted that Chunghwa Telecom had already reported partial fiber-core damage at the same location on March 30, 2026, and this time the renewed damage led to a complete break.

As for the cause of the complete break, moda’s press release states that “according to the company’s preliminary assessment, the fault was suspected to have been caused by poor sea conditions that shifted the wreckage of a previously grounded vessel, damaging the cable” — this is Chunghwa Telecom’s own preliminary assessment, relayed by moda, not a confirmed investigative conclusion. After the outage, Chunghwa Telecom activated microwave backup under standard operating procedure, shifting the voice and internet services normally carried over the cable onto it; moda said that mobile phone, voice, and data services in the Dongyin area remained normal at the time, though weather could cause slight delays to some internet service, while cable TV service could not use the microwave backup because it lacked conversion equipment. moda also said that, sea conditions permitting, repairs were expected to be completed by the end of July 2026 — that end-of-July estimate was made on April 29 itself, and none of the four official documents this article cites states when this complete break was ultimately repaired; this article does not fill in that gap either.

What Chunghwa Telecom’s Own Announcement Says: “Partial Fiber-Core Restoration”

Besides moda’s press releases, Chunghwa Telecom also posts its own announcements about the status of Matsu’s outbound cables in the message section of its official website. The one this article cites has its own URL and date label and can be opened to read directly: the title is “Notice on the Repair of the Taiwan–Matsu No. 2 Cable (TDM2) Fault” (Chinese: 「台馬第二海纜(TDM2)障礙修復說明」), the page is dated 2026/05/25, and the body is a single sentence: “Chunghwa Telecom’s Taiwan–Matsu No. 2 cable (TDM2) completed a partial fiber-core restoration on May 25 and resumed dual-cable operation.” (Chinese: 「中華電信公司台馬第二海纜(TDM2)，已於05月25日完成部分芯線搶通並恢復雙海纜運作。」) The abbreviation TDM2 for the Taiwan–Matsu No. 2 cable and TM3 for the Taiwan–Matsu No. 3 cable come from the Chinese full names and English abbreviations paired in the same row of the domestic cable list on moda’s “Latest Submarine Cable Status” page.

The wording in this announcement is “partial” fiber-core restoration — it does not say that all the damaged fiber cores have been fixed, and it does not further state when the remaining fiber cores will be repaired; it likewise does not say when or where the fault on the Taiwan–Matsu No. 2 cable occurred. The June 23 press release does mention that “the Taiwan–Matsu No. 2 and No. 3 cables recently developed faults simultaneously in the Dongyin area,” but it gives no date and does not say whether that is the same fault this announcement repaired; this article does not link the two, nor does it fill in the date of the break. For readers, this means that when a Chunghwa Telecom or moda announcement uses words like “repaired” or “restored,” the safer approach is to open the original announcement directly and check its scope — Chunghwa Telecom’s announcements in its message section are, alongside moda’s press releases, another first-hand source for checking the status of Matsu’s cables.

What These Four Official Documents Do Not Say

Among the four official documents this article cites, there are still plenty of details about the Taiwan–Matsu No. 4 cable that go unstated: the June 23 press release only says it is “coming to completion soon,” with no specific completion or activation date; the cable’s length, capacity, landing-station location, and contractor, as well as how many microwave units each of Matsu’s four townships actually has and what they cost, are likewise not stated in the press release — it only gives the post-completion floor of “at least 2 per township.” Nor does the statement that “there will be 3 submarine cables between Taiwan and Matsu” once it is activated further explain which 3 cables, or how they relate to the Taiwan–Matsu No. 1, No. 2, and No. 3 cables on the domestic cable list as of the fact-check date — for now, that sentence can only be quoted from the official original; it cannot be inferred further.

As for the funding source for the Taiwan–Matsu No. 4 cable, officials state that it was “built by Chunghwa Telecom with Forward-looking Infrastructure subsidies”; the press release gives no amount and no subsidy ratio. The release’s mention that “the Taiwan–Matsu No. 2 and No. 3 cables recently developed faults simultaneously in the Dongyin area” also does not say what day that happened; this article separately found that the Taiwan–Matsu No. 3 cable suffered a complete break at Dongyin in late April (see the previous section), but moda’s sentence itself does not name which event that was, and this article does not identify it either.

The State of Things as of the Fact-Check Date, and How to Check It Yourself

Under “Key Policies,” moda separately maintains a “Latest Submarine Cable Status” page listing Taiwan’s current international and domestic submarine cables. When this article checked it on September 17, 2026, the page stated: “Taiwan currently has 16 international communication cables and 10 domestic communication cables.” The domestic cable table lists, in order, Taiwan–Kinmen No. 2, Taiwan–Matsu No. 1, Taiwan–Matsu No. 2, Taiwan–Matsu No. 3, Taiwan–Penghu No. 2, Taiwan–Penghu No. 3, Penghu–Kinmen No. 1, Penghu–Kinmen No. 3, Xiaoliuqiu No. 1, and Xiaoliuqiu No. 2 — the Taiwan–Matsu No. 4 cable is not on this list. This page has no fixed “last updated” date to cite, because the date shown in the footer is written in automatically by the page’s script at the moment a user opens it; it can only record “what was shown on the day it was checked,” not some fixed version timestamp, and the list itself will also change as cables are added or removed.

Readers who want to check the latest status can go directly to the “Latest Submarine Cable Status” page under “Key Policies” on moda’s official website, or search moda’s “News Releases” for the newest announcement about the Taiwan–Matsu No. 4 cable; Chunghwa Telecom’s own announcements are in the message section of its official website. None of the four official documents this article cites describes what the actual communications experience between Taiwan and Matsu will be like once the Taiwan–Matsu No. 4 cable is activated, and this article has not conducted any on-site testing either; such details will have to wait for the government or the telecom carrier to publish them.

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