Hidden Telecom Equipment Winners Surviving the 5G Winter — and the Return of AI and Optical Networking

The telecom equipment industry has always lived in the shadow of Samsung Electronics’ Network Business and the three major telecom carriers. But on the ground, what really determines the sector’s staying power is who makes the base station RF filters, who supplies the antennas, and who underpins the optical transport and fixed subscriber network equipment. Looking only at the domestic market, the picture is frustrating. 5G investment has already passed its peak, orders have declined, and equipment makers see earnings swing on every move in the telecom carriers’ capex plans.

That said, the game is not completely over. Wireless has cooled, but optical is heating up again. As AI data centers drive 400G—and increasingly 800G-class—traffic higher, demand for optical transceivers is coming back. At the same time, RF technology is not just for telecom anymore. The telecom equipment industry’s survival formula now lies in moving away from dependence on domestic 5G and shifting toward exports, data centers, and defense RF. The gap is likely to widen further between companies that have made this transition and those still tied to telecom carrier orders.

Base Stations, Antennas, RF — The Core of 5G Wireless (5 companies)

The heart of 5G wireless is still the base station and RF. But this was also the first segment to get hit by the cold. That’s because RF filters, integrated RRH equipment, antennas, enclosures, and even small cells all sit directly in the path of the 5G investment cycle. At the peak of spending, they benefit massively from network expansion. But once capex rolls over, inventory and fixed costs turn into a burden all at once. If you ask why base station RF vendors can’t avoid talk of losses and restructuring, the answer is simple: too few customers, and too much cyclicality.

This is where the differences between companies become crystal clear. KMW is a leading player making 5G base station RF filters, MMRs (integrated RRH units), and antennas, supplying Nokia and ZTE. RFHIC is the only company in Korea mass-producing gallium nitride (GaN) RF semiconductors, and what sets it apart is that its transistors and power amplifiers can extend beyond base stations into defense radar. Ace Technologies handles both base station antennas and RF components as well as automotive and defense antennas, but has been struggling as the 5G slowdown weighs on earnings. Seojin System manufactures telecom enclosure structures such as RRH, BBU, and cabinets, while broadening its portfolio into secondary battery and ESS case EMS. Innowireless stands out as Korea’s only player in both 5G small cells and telecom test & measurement (T&M). The key question in wireless now is who, at the end of the 5G buildout cycle, has secured demand outside telecom.

Company	Core business
KMW	5G base station RF filters, MMRs (integrated RRH units), and antennas — supplies Nokia and ZTE
RFHIC	Gallium nitride (GaN) RF semiconductors (transistors and power amplifiers), the only mass producer in Korea — base stations + defense radar
Ace Technologies	Base station antennas and RF components + automotive and defense antennas (earnings under pressure from the 5G slowdown)
Seojin System	Telecom enclosure structures (RRH, BBU, cabinets) + secondary battery and ESS case EMS
Innowireless	5G small cells + telecom test & measurement (T&M), the only domestic player

Repeaters, In-Building, and Transport — Seamless Coverage (3 companies)

Telecom doesn’t end with simply putting up base stations. To keep signals flowing seamlessly inside crowded buildings, underground spaces, and mixed-use complexes, you need repeaters and DAS, along with optical transport equipment to carry that traffic. This segment may look less glamorous on the surface, but it is what ultimately determines real-world service quality and operating efficiency. The Open RAN trend could also create fresh opportunities for exactly these mid-layer equipment vendors.

Solid makes repeaters (DAS) and optical transport equipment, ranking No. 3 globally in DAS with roughly a 15% share, and it is also moving into Open RAN. Coweaver is Korea’s No. 1 supplier of optical transport MSPP and POTN equipment, serving all three major telecom carriers. Woorinet is active in packet-optical transport (POTN) and quantum cryptography (QKD) equipment. Still, let’s be blunt. Even here, if you look only at the domestic market, dependence on orders from the three telecom carriers remains high. The future of repeater and transport equipment depends less on domestic coverage upgrades themselves and more on how far these companies can expand the playing field through Open RAN, private networks, and exports.

Company	Core focus
Solid	Repeaters (DAS) and optical transport — No. 3 global DAS share (~15%), expanding into Open RAN
Coweaver	Korea’s No. 1 in optical transport MSPP and POTN equipment — supplies the three major telecom carriers
Woorinet	Packet-optical transport (POTN) and quantum cryptography (QKD) equipment

Optical Communications & Wired Networks — The Highways of AI Traffic (4 companies)

The most interesting reversal in telecom equipment right now is optical communications. For a while, 5G wireless gear had the spotlight all to itself, but as AI is driving an explosion in data center traffic, high-speed optical modules and wired network equipment are becoming critical again. In the end, traffic flows over fiber. If wireless is the entry point in the air, optical is the highway that actually carries the data.

OE Solutions is Korea’s No. 1 company in optical transceivers—that is, optical communication modules—and it is one of the clearest direct plays on 400G, data centers, and AI demand. Lightron is a company focused on optical transceivers and optical components, though its current corporate name is VITZRO Liteon. Ubiquoss makes switches and FTTH access network equipment and ranks No. 1 in wired subscriber networks for Korean telecom carriers. Dasan Networks handles wired network equipment such as FTTx and Ethernet switches, and operates under a holding company structure with manufacturing subsidiaries beneath it. In the AI era, the real rerating in telecom equipment is showing up first not in base stations, but in optical transceivers, wired access networks, and switches.

Company	Core business
OE Solutions	Korea’s No. 1 optical transceiver (optical communication module) company — beneficiary of 400G, data centers, and AI
Lightron	Optical transceivers and optical components (current corporate name: VITZRO Liteon)
Ubiquoss	Switches and FTTH access network equipment — No. 1 in wired subscriber networks for Korean telecom carriers
Dasan Networks	Wired network equipment (FTTx, Ethernet switches) — holding company (with manufacturing subsidiaries)

What to Watch Going Forward

The next phase is likely to become much clearer. Data centers are set to pull optical communications higher, renewed 6G discussions could reshape the direction of wireless technology, and defense RF may open up a new market for high-value semiconductors such as GaN. That is why the picture matters: optical module makers like OE Solutions standing directly in the path of rising AI traffic demand, and companies like RFHIC looking beyond base stations to defense radar as a new growth avenue. Not all telecom equipment is the same. From here, corporate value will be determined by which traffic, which customers, and which budgets a company is tied to.

But this should not be viewed through rose-colored glasses alone. The sharp drop in domestic 5G capex has already left deep scars across many base station, antenna, and RF vendors. Dependence on orders from Korea’s three telecom operators remains a structural challenge. The cycle is simply too volatile to endure by relying only on the domestic market. That makes the survival formula quite clear. Only companies that move beyond the domestic cycle centered on the three telecom carriers and shift their customer base and demand exposure toward exports, data centers, and defense will be able to deliver meaningful growth in the next phase. If that transition comes too late, even firms with strong technology may be forced to endure a much longer winter. The market has always been that unforgiving.

※ This article is based on publicly available materials cross-checked online to summarize company names, core businesses, and market positions, and some assessments reflect the author’s views. It is not intended as a direct basis for investment decisions.

Written: July 2026. Ealexandro