of which only one is in use. Use of additional pairs requires new equipment to be installed in Harstad and Hotellneset. Segment 2 is redundant to Segment 1 and is only used if the former should fall out. Near shore the cables are armored. On the main section, each segment is equipped with twenty optical communications repeaters. These run off direct current fed from Breivika, with the seawater and seabed used for return current. Power is provided through a single-end feed; although supplying from both ends is safer, a single feed was regarded as sufficient. The cables are fed 1.1 ampere at 2,500 volt, fed from two redundant converters. Each repeater has eight erbium doped fiber amplifier pairs. The pairs operate independently of each other, including having their own power supply, allowing for redundancy should one fall out. The repeaters have an estimated lifetime of twenty-five years. The cables are equipped with an ocean ground protection panel to provide isolation and thus hinder damage from lightning. If it is necessary to pick up the cables, the power feed equipment can send a 4 to 5 hertz sine wave through the high-voltage output, which can be detected on the seabed. Line terminating equipment (LTE) is installed at Longyearbyen and Harstad. The system is capable of handling the entire length without regeneration of the signal. It employs clear-channel transmission, which is protocol-independent, with the transmissions using the Synchronous Digital Hierarchy protocols. The LTE is fed both an STM-1 at 155 Mbit/s and an STM-64 at 10 Gbit/s, resulting in a STM-64 and OC-192 protocol for transmission. The system is monitored using the Tyco Element Manager System, which are installed in Longyearbyen, Harstad and at Telenor's Network Operations Center in Fornebu. The system can be extended to 2,500 Gbit/s on each cable, by employing all pairs and adding additional wavelengths. Severing of the Undersea cable The Svalbard undersea cable system connecting the archipelago to the mainland was unexpectedly severed in January of 2022. A preliminary police investigation implicates human activity. References Communications in Svalbard Science and technology in Svalbard Submarine communications cables in the North Atlantic Ocean Telenor 2003 establishments in Norway Internet in Norway