All aboard SEA-ME-WE 6
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All aboard SEA-ME-WE 6

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Yue Meng Fai, chairperson of the SEA-ME-WE 6 consortium, talks to Saf Malik about the cable’s progress and its importance to the telecoms industry.

The Southeast Asia-Middle East East-West Europe 6 (SEA-ME-WE 6) cable is one of the largest and most important subsea cable projects in development today. Despite reports of setbacks, the cable is still on track to be in service by 2025.

The final cost of laying the 19,200km link between Singapore and France, which crosses Egypt, is estimated to be around US$500 million. But earlier this year, amid rising tensions between China and the United States, the Financial Times revealed that China Telecom and China Mobile had withdrawn their investments in SEA-ME-WE 6. The report said that the withdrawals followed US company SubCom confirming it had won the supply contract for the cable, that had been in force since last year. The US firm allegedly beat competition from HMN Technologies, the Chinese subsea cable provider that had been previously owned by Huawei.

The FT’s report received widespread attention and coverage, given the increasing geopolitical tensions between the US and China. Since 2020, the US has denied permission for several subsea cables that involved Chinese companies, citing national security concerns.

Additionally, the combined investment of the two Chinese firms was rumoured to be around 20% of the project’s cost, raising further questions about its financing.

But Yue Meng Fai, chairperson of the SEA-ME-WE 6 project and senior director of consortium cable engineering at Singtel, says that both China Telecom and China Mobile left the consortium quite early on in the process. “More than a year ago,” he says.

As for their reasons, Meng Fai is not concerned. “They have their own businesses, risk appetite and investment levels to consider.”

Meng Fai adds that it is not unusual for several companies involved in the consortiums that install cables to withdraw involvement.

But he is keen to stress that, despite the continuing US-China tensions, China Unicom, a smaller state-owned company, remains involved with SEA-ME-WE 6.

Despite that, China Telecom, China Mobile and China Unicom are rumoured to be planning a new cable, Europe-Middle East-Asia (EMA), that would rival SEA-ME-WE 6.

EMA would reportedly link Hong Kong to Hainan, an island province that forms China’s southernmost point, and Singapore, Pakistan, Saudi Arabia, Egypt and France.


SEA-ME-WE 6 is the latest iteration of a subsea cable that was introduced in 1984. Singtel, Singapore’s largest mobile network operator, has played a leading role in each of the cables that have come before it.

In 1985, a consortium of 22 operators from 21 countries completed work on SEA-ME-WE 1, at a cost of more than S$800 million (US$600,000,000 at the time). At the time, it was one of the longest submarine cables in the world at 13,000km, with eight segments linking Singapore to France via Indonesia, Sri Lanka, Djibouti, Saudi Arabia, Egypt and Italy.

Until then, except for trans-border telecoms using a terrestrial land coaxial cable and microwave links, international telecoms between East Asia, the Middle East and Europe depended almost entirely on satellite communications. The introduction of SEA-ME-WE 1 created an alternative link for the countries in the Indian Ocean.

In Singapore, SEA-ME-WE 1 was interconnected with existing submarine cables, such as the ASEAN submarine cable that had been completed in 1984.

Two other subsea cable systems completed in 1986 were the Singapore-Hong Kong-Taiwan Submarine Cable System and the Singapore-Indonesia-Australia Submarine Cable System.

SEA-ME-WE 1 was withdrawn from service in 1999. Since then, four more were built, with carriers that were not incumbents in their respective countries joining the consortium responsible for SEA-ME-WE 5.

The latest iteration of the cable, which is due to be launched in 2025, is more advanced and robust than its predecessors and will play a critical role in meeting the growing demand for high-speed internet connectivity and data transmission between participating countries.

Subsea cables are typically owned by consortiums, which are responsible for the associated costs. SEA-ME-WE 6’s consortium includes Bharti Airtel, Orange, Telekom Egypt and Singtel.

“With a consortium, there are certain ground rules,” says Meng Fai. “Consortium cables have evolved since the 1970s. The management committee will assign or form different working groups. So, it’s more transparent now, some may think it’s a slow process, but I think it is a good model.”

Meng Fai began his career as a cable engineer, repairing submarine cables in his early 30s. After spending a few years on a cable ship, the opportunity came for Meng Fai to join Singtel to begin planning several subsea cables. He joined the company in 2000 and has been with it ever since.

“It’s more of a progression for me,” he says of his role as chairperson of the SEA-ME-WE 6 management committee.

A league of its own

Having been in the industry for some time now, Meng Fai sees the profound importance of subsea cables to the world.

Subsea cables are the lifeline of a modern connected world. Around the world, more than 400 cables run along seabeds carrying at least 95% of all international internet traffic, according to TeleGeography. In recent times, big tech firms, such as Google, Amazon, Microsoft and Facebook, have laid and now operate their own cables. These are as important to these firms as their data centres, and Meng Fai believes data centre operators and subsea cable owners can work more closely moving forward.

Despite their importance, misconceptions about subsea cables from the general public remain. Many outside the telecoms industry believe they connect to satellite networks, but that is rarely the case.

“The satellite industry is not able to emit as much capacity as submarine cables,” Meng Fai says. “Especially if we’re talking about optical submarine cables, [satellite is] not even in the same league.”

While he notes there are advantages to satellite connectivity, particularly for cities and landlocked countries, he believes advances the submarine cable industry has made since the 1980s has put it into a league of its own.

The SEA-ME-WE 6 cable consists of 10 fibre pairs with 12.6Tbps per fibre pair for a total system capacity 126Tbps and uses the latest spatial division multiplexing (SDM) technology.

SubCom is using an SL17-SDM cable for the new system. As this cable supports up to 24 fibre pairs, SEA ME WE 6 could more than double the capacity of the cables in the line. Manufacturing the cable and equipment will be carried out at SubCom’s US campus in Newington, New Hampshire.

The increase in capacity is due to increasing demand on a route that goes from Southeast Asia, through the Indian Ocean to the Middle East and then to Europe, which Meng Fai describes as “lucrative”.

“Due to high bandwidth demand, especially with all the social media use, the demand has driven the need for higher capacity,” he says.

The new cable will also leverage SubCom’s 18kV power source technology, enabling SEA-ME-WE 6 to maintain operations with single-end feed in the event of a far-end fault.

Each network segment of SEA-ME-WE 6 has individually designed fibre pair capacities, together with the overall segment fibre pair counts, that will provide multi-terabit end-to-end capacity while optimising the overall price of the system.

SEA-ME-WE 6’s system is made up of three parts: a subsea branch from Tuas, Singapore to Ras Ghareb, Egypt; a terrestrial segment between Ras Ghareb to Port Said, Egypt; and another final undersea tranche running to Marseilles, France.


A notable vulnerability of the existing undersea cable network is the lack of diversity in cable routes. This is limited for several reasons, including the cost and difficulty securing permitting requirements, seabed topography, the cost and ease of laying cables, and marine environment protection. Meng Fai says a diverse route was essential for SEA-ME-WE 6.

“When we first designed the configuration of the cable, the criteria are based upon which countries we want the cable to be connected to,” Meng Fai says.

Meng Fai adds that companies do not want to rely on single cables, in case it is damaged. This is a common problem for subsea cables and has happened to SEA-ME-WE cables before. Meng Fai says significant damage to the SEA-ME-WE 3 cable in 2016 was caused by a cable being cut 1,125km from its landing station in Tuas, Singapore.

“Previously there were parties that advocated for self-healing configuration, which is designed in a ring,” he says.

With this technology, in the event of a link or an entire station being lost, the nearest surviving stations loopback their ends of the ring.

In this way, traffic can still travel to the surviving parts of the ring, even if it has to travel “the long way around”, says Meng Fai.

“But because this configuration is very expensive and you need more than one route to swing your traffic to, we’ve opted for the ‘fishbone’ configuration,” Meng Fai says, adding that it has a wider reach and is less expensive to maintain.

SEA-ME-WE 6 is on track to launch in 2025. He believes that such high-capacity cables will be able to work in tandem with 5G and 6G applications and the data centre industry.

“As the world moves into the next stage of connectivity, where discussions are taking place about autonomous vehicles, these are 5G applications that would need high bandwidth and short latency connectivity,” says Meng Fai.

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