Frequently Asked Questions


What is Alaska United and how is it organized?

Alaska United Fiber System (AU-North and AU-East) is a partnership of two wholly-owned subsidiaries of GCI. It is the state’s first fiber optic network to connect the largest population centers of Alaska. Alaska United Fiber System utilizes undersea and terrestrial connections to extend high capacity fiber optics to Anchorage, Fairbanks, Juneau, Whittier and Valdez.

Alaska United West is an asset purchased and operated by GCI Communication Corp. Although the entire Alaska United Network is operated seamlessly under GCI control there are distinct business organization differences. 

Alaska United is the communications equivalent of an Interstate highway system. It enables the deployment of new, bandwidth hungry communication applications such as faster Internet, ISDN, video conferencing, telemedicine and distance education.

Alaska United, when combined with GCI’s previous investments in Alaska tailored satellite capacity (Galaxy IX, Galaxy Xr, Galaxy XVIII), provides unparalleled communication coverage throughout the state.

Why did we build this cable?

Customers in Alaska were starved for bandwidth capacity, and that demand continues to. This bandwidth crunch restricted the deployment of new communication services and the development and diversification of the state’s economy. In addition, AU-West construction was completed during a period of low submarine cable supply demand allowing GCI to deploy the system with the industries top resources on hand.

What fiber connectivity existed in Alaska prior to Alaska United?

North Pacific Cable (NPC) terminates in Seward with a terrestrial fiber that connects to Anchorage. NPC had a total capacity of nine DS-3 (420 Mb/s) or approximately 6,048 clear channel voice/data circuits. There was no fiber to Juneau, and had been none to Fairbanks.

What are the capacities of this cable?

At start-up in 1999, AU-East capacity was a minimum of OC-48 = 32,256 voice/data circuits at 2.5 GB/s. As demand has increased, capacity upgraded to allow multiple OC-192 = 129,024 voice/data circuits at 10 GB/s. Capacity is upgraded by adding optical electronics at the shore station–no “wet plant” work is required.

AU-West is at OC-192 level with a commercial design capacity of 640 GB/s or 82.5 million voice/data circuits.

AU-North is currently operating at multiple OC-48 or 2.5 GB/s level. The capacity of the AU-North segment can be increase either by the utilization of unused dark fibers or through adding additional wavelengths to the current fibers in use.

What is the route? How was it selected?

The marine routing of the three segments of the Alaska United Network where carefully chosen to provide the safest routing of the cable with least conflict with historical uses of the seafloor. Initial route planning was conducted as a desktop study that included information gathered from local fishermen, pilots, USCG, Harbormasters, and permit agencies. Drawing on the results of a desktop study, a marine survey was conducted for GCI by FSSI on each segment. The system supplier’s then engineered the final cable route. In several cases, the route was further adjusted due to additional input from fishermen, permit agencies and conditions encountered during the installation. The route designed included the avoidance of areas known for heavy bottom fishing. Inland extensions to Juneau, Anchorage, Ketchikan, and Seattle are configured in a physically diverse SONET ring to afford maximum protection against outage.

What are the vitals of Alaska United?

LENGTH:  Alaska United network is a total of 5,970 statute miles of which 4,988 miles is subsea and 982 miles are overland.

  • Seattle to branching unit is 1276 miles.
  • Branching unit to Juneau is 509 miles.
  • Branching unit to Whittier is 860 miles.
  • Whittier to Valdez is 95 miles.
  • Warrenton, OR to Seward is 1494 miles.
  • Ketchikan to BU is 372 miles.
  • The SEAFAST system is 382 miles.
  • Valdez to Fairbanks is an estimated 284 miles.
  • Anchorage to Fairbanks is 345 miles.
  • Whittier to Anchorage is 50 miles.
  • The In addition 303 miles are a combination of lease capacity or acquired dark fiber.

REPEATERS:  Alaska United includes 67 optical amplifiers (also called EDFAs, Erbium-doped Fiber Amplifiers). AU-East has 33 and AU-West has 34. These undersea amplifiers are integrated into the cable and are powered by “constant-current” PFEs (power feed equipment) located at the six cable landing stations. These EDFAs amplify the optical signal without any conversion to an intermediate electrical signal.

AU-North does not have subsea amplifiers. The capacity on AU-North is regenerated at Whitier, Valdez and along the pipeline corridor. AU-North currently operates at multiple OC-48 signal level.

STRANDS:  Alaska United is designed to support WDM (wavelength division multiplexing) whereby separate wavelengths (colors) each can carry an OC-192 (optical carrier level 192 which is 9.95328 Mbps or 129,024 traditional voice circuits). Currently Alaska United is carrying one completely ringed OC-192 signal with additional OC-192 capacity on stand alone portions of the network. Each fiber pair can be upgraded to additional OC-192 channels by adding shore-based electronics without changing the wet plant.

Alaska United has a minimum four fiber strands in all cable cross-sections (i.e., 2-fiber ring in a common cable sheath). There are up to 48 fiber strands in the terrestrial cable sections. One PSBU (power-switched branching unit) is included in Alaska United- East and provides a common point where the three undersea cable segments are joined. The PSBU provides the ability to remotely switch the power configuration of the cable and thereby enhance system reliability. The SONET terminal equipment can interface standard asynchronous and synchronous circuit types including: DS-1, DS-3, OC-1, OC-3, OC-12, OC-48, and EC-1 (electrical carrier level 1). SEAFAST has a minimum of 24 fibers in each cable segment.

What is SONET and how is it an advantage?

SONET stands for Synchronous Optical NETwork and is a fiber optic transport standard developed by ANSI (American National Standard Institute). SONET has the key advantages of providing high-capacity fiber optic transport, defines a system of synchronous signal levels, includes a high-level of OAM&P (Operations, Administration, Maintenance, and Provisioning) capability, supports automatic protection switching, allows a high-degree of interoperability between different vendor platforms, etc.

Relative to Alaska United, define protection, bit error rate, route diversity?

PROTECTION:  Alaska United East and West create a diversely routed SONET ring system, which includes automatic protection switching (APS) to protect against failure of any individual electronic or fiber optic component of the network – including a cable cut in the system. Alaska United North has SONET protection but currently it is in a collapsed ring where both sides of the ring network are physically located in the same cable sheath. This configuration allows for protection against failure of any individual electronic or fiber optic component of the network not including an actual cable cut.

BER:  the ratio of error bits to the total number of bits transmitted. Alaska United is an astoundingly small one bit error occurring every 10,000,000,000,000 (trillion) bits sent (this is three to four orders of magnitude better than satellite or microwave).

DIVERSITY:  by itself, Alaska United does have “route diversity” on the AU-East and AU-West segments since the fiber ring is contained in separate distinct cable sheaths. AU-North does not have diversity and is a collapsed ring configuration.

What types of hazards does a subsea cable face?

The primary causes of external aggression are bottom fishing, ocean currents, and geological events such as earthquakes and volcanoes. However, 95 percent of submarine cable failures are attributable to fishing activities. To guard against these factors, Alaska United is plow buried from shore to a depth of 4,900 feet or greater except in rocky areas where bottom conditions don’t permit burial or fishing. Additionally, the route was adjusted to avoid geological hazards.

What precautions are taken to minimize hazards?

The cable route was selected to avoid as many external aggression factors as feasibly possible. Extensive research of fishing activities and practices allowed AU to avoid busy fishing areas. Cable armoring and burial is in areas where a potential fishing area was unavoidable. GCI ensures that the Alaska United cable route is identified as a “cable protection route” on nautical charts. GCI actively communicates with the fishing industry and monitor fishing activities to decrease the possibility of damage to the cable. GCI maintains an active hot line to GCI network operation center to assist any fisherman that may mistakenly come in contact with one of the cables.