AT&T is ranked No. 1 for the third consecutive year on Vertical Systems Group’s (VSG) year-end U.S. Fiber-Lit Buildings Leaderboard.

The 11 retail and wholesale fiber providers that qualify for this benchmark had 10,000 or more on-net U.S. fiber-lit commercial buildings as of the end of 2018. Following AT&T in order of ranking are Verizon, Spectrum Enterprise, CenturyLink, Comcast, Cox, Crown Castle Fiber, Frontier, Zayo, Altice USA and Windstream.

Frontier moved to the eighth position, up from ninth in the prior year. As a result, Zayo falls to ninth, down from eighth.

Windstream entered the leaderboard at 11th, moving up from the “Challenge Tier.”

“Following a flurry of mergers and acquisitions, fiber providers focused on new build-outs in 2018 to meet customer demand for higher-speed dedicated access to business services and to support 5G pilots,” said Rosemary Cochran, VSG principal. “Our research shows that while the majority of large and medium-size commercial buildings in the U.S. are fiber lit with one or more providers, relatively few small multitenant buildings are fiber-connected. Cable MSOs and regional network operators have been most actively targeting fiber investment opportunities in this underserved segment.”

A fiber-lit building is defined as a commercial site or data center that has on-net optical fiber connectivity to a network provider’s infrastructure, plus active service termination equipment onsite. Excluded from the leaderboard are standalone cell towers, small cells not located in fiber-lit buildings, near-net buildings, buildings classified as coiled at curb or coiled in building, HFC-connected buildings, carrier central offices, residential buildings, and private or dark fiber installations.

Additionally, 13 companies qualified for the 2018 Challenge Tier, including Atlantic Broadband, Cincinnati Bell, Cleareon, Cogent, Consolidated Communications, FiberLight, FirstLight, GTT, IFN, Logix Fiber Networks, Segra, Unite Private Networks and Uniti Fiber. They qualified with 2,000-9,999 U.S. fiber lit commercial buildings.

Atlantic Broadband and GTT advanced to the Challenge Tier, both moving up from the “Market Player” tier.

The Market Player tier includes all other fiber providers with fewer than 2,000 U.S. commercial fiber-lit buildings. It features such companies as Fusion, Google Fiber, TPx and WOW! Business