Sardinia the highest internet performances, such as fastest broadband connection in Italy. Sardinia is also the Italian region with the highest percentage (41%) of 4G LTE users. The Chinese multinational telecommunications equipment and systems companies ZTE and Huawei have development centers and innovation labs in Sardinia. Sardinia has become Europe's first region to fully adopt the new Digital Terrestrial Television broadcasting standard. From 1 November 2008 TV channels are broadcast only in digital. Sardinia has three international airports (Alghero-Fertilia/Riviera del Corallo Airport, Olbia-Costa Smeralda Airport and Cagliari-Elmas Airport) connected with the principal Italian cities and many European destinations, mainly in the
Kingdom of Sardinia Sardinia, including the city of Alghero and the semiautonomous Republic of Sassari, and added them to its direct domains. The Giudicato of Arborea, the only Sardinian state that remained independent of foreign domination, proved far more difficult to subdue. Threatened by the Aragonese claims of suzerainty and consolidation of the rest of the island, in 1353 Arborea, under the leadership of Marianus IV, started the conquest of the remaining Sardinian territories, which formed the Kingdom of Sardinia. In 1368 an Arborean offensive succeeded in nearly driving the Aragonese from the island, reducing the "Kingdom of Sardinia and Corsica" to just