Reach North Asia Loop (RNAL) is a multi-

terabit The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as ...

intra-Asia self-healing submarine telecommunications cable system, connecting the principal cities in Asia. The 10,000 km cable network provides intra-regional, city-to-city connectivity between Hong Kong, Seoul, Tokyo, and Taipei. The cable network was developed jointly by Reach and FLAG Telecom. Reach has constructed the eastern leg of the multi-terabit cable that connects Japan, Taiwan, and Hong Kong, while FLAG built the western leg connecting Japan, Hong Kong, and Korea.

Overview

FLAG manages and operates the system on its own behalf and that of Reach under a developmental agreement. FLAG and Reach each own three of the system's six

fiber Fiber (spelled fibre in British English; from ) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often inco ...

pairs. Reach markets its share of the system as Reach North Asia Loop (RNAL). RNAL has the largest share of cable capacity in Asia with 29% (the second largest is C2C with 25%). It has landing points in: * Tong Fuk,

Lantau Island Lantau Island (also Lantao Island, Lan Tao or Lan Tau) is the largest island in Hong Kong, located west of Hong Kong Island and the Kowloon Peninsula, and is part of the New Territories. Administratively, most of Lantau Island is part of the ...

Hong Kong Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...

Pusan Busan (), officially Busan Metropolitan City, is South Korea's second most populous city after Seoul, with a population of over 3.3 million as of 2024. Formerly romanized as Pusan, it is the economic, cultural and educational center of southe ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

* Wada, Awa District,

Chiba Prefecture is a Prefectures of Japan, prefecture of Japan located in the Kantō region of Honshu. Chiba Prefecture has a population of 6,278,060 (1 June 2019) and has a geographic area of . Chiba Prefecture borders Ibaraki Prefecture to the north, Saitama ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

* Toucheng, Yilan County,

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

Technology

RNAL is a high-capacity 6-

-pair redundant loop system, upgradeable using Dense Wave Division Multiplexing (DWDM). Reach owns 3 fiber pairs and FLAG owns the other 3 fiber pairs.

Service Availability and Configuration

The cable landing shore ends are buried through plough and jetting techniques to minimise the possible impact of fishing, large ship anchors and other ocean hazards that can occur in shallow water. Armored cable protection is also utilised in shallow water areas including the shore ends. The RNAL is a self-healing loop cable with a traffic restoration time of less than 1 second in the event of a cable fault and availability of 99.999% (about 5 minutes of downtime per year). Damage to RNAL was reported as affecting internet traffic to China on 18 August 2009.

Upgrade

In January 2012

PCCW Global HKT Limited (), also known as Hong Kong Telecom (), is one of the largest telecommunications companies in Hong Kong. It has a dominant position in fixed-line, mobile, IDD and broadband services in Hong Kong. HKT Group is a subsidiary of PCCW ...

and

Ciena Ciena Corporation is an American optical networking systems and software company based in Hanover, Maryland. The company has been described as a vital player in optical connectivity. The company reported revenues of $4 billion and more than 8,50 ...

Corporation jointly announced their intent to upgrade RNAL with Ciena's WaveLogic coherent optical 100G networking solutions.

will light a ring of

dark fiber A dark fibre or unlit fibre is an unused optical fibre, available for use in fibre-optic communication. Dark fibre may be leased from a network service provider. Dark fibre originally referred to the potential network capacity of telecommuni ...

s on RNAL so that it can support significantly more than its original design capacity.

External links

Comprehensive list of the approximately 1000 cable landing sites globally

References

{{Submarine communications cables in the Pacific Ocean Submarine communications cables in the Pacific Ocean Japan–South Korea relations