Long haul and middle mile fiber for AI data centers

In short

The United States is in the largest expansion of its long haul fiber network in a generation, driven by AI data centers that need far more bandwidth than traditional cloud facilities. The national inventory of long haul fiber miles is on track to more than double by 2029, from 159 million to 373 million. Private builders like Lumen and Zayo have announced tens of thousands of new route miles, backed by billions in hyperscaler commitments. S&P Global analysis, Zayo press release The NTIA Middle Mile Program is adding over 12,500 miles of fiber with nearly $1 billion in federal grants. BroadbandUSA For fiber crossing federal land, a 270 day shot clock applies under the MOBILE NOW Act, but NEPA environmental reviews still cause years long delays in many cases. BLM Final Rule, CEQ EIS Timeline Report The FCC leaves long haul backbone pricing and interconnection to private contract, which has encouraged bespoke dark fiber deals of unprecedented scale.

What are long haul and middle mile fiber networks?

Long haul fiber refers to the backbone cables that move data across cities, states, and regions. Middle mile fiber connects regional internet hubs to one another and to the long haul backbone, but it does not reach the end user. The NTIA’s statutory definition of middle mile infrastructure covers any broadband infrastructure that does not connect directly to an end user location, including leased dark fiber, transport connectivity to data centers, and undersea cables. NTIA Middle Mile FAQ, 47 U.S.C. § 1741(a)(9)

AI data centers are different from traditional cloud data centers because they house massive GPU clusters that train and run large language models. A single AI cluster can require roughly 10 times more optical fiber connections inside the building. FBA Fiber Forward Magazine, Corning NTIA comments Those inter-facility links, called data center interconnect or DCI, let hundreds or thousands of GPUs synchronize with each other during training. From 2020 to 2024, the total DCI bandwidth purchased grew nearly 330%, with total bandwidth purchases reaching 42.4 terabits per second of active capacity. Data Center Knowledge, Om Malik Ten large buyers, mostly the major cloud providers and carriers, accounted for nearly 62% of all bandwidth purchases in 2024. Om Malik

How much more fiber do AI data centers need, and how fast is it growing?

The United States had an estimated 95,000 unique long-haul route miles and 159 million fiber miles in 2024. Fiber Broadband Association, FBA/RVA white paper The Fiber Broadband Association projects that those figures must reach roughly 187,000 route miles and 373 million fiber miles by 2029. Achieving that would require laying 214 million additional fiber miles over five years, more than doubling the existing fiber plant. FBA study

The 214 million new miles break into three pieces.

• 109 million miles for upgrading existing routes, such as pulling more strands through existing conduit.
• 66 million fiber miles for new laterals that will connect newly built AI data center campuses to the backbone.
• 38 million miles for new long haul routes. FBA white paper

Annual new fiber additions are forecast to climb from about 30 million miles in 2025 to nearly 60 million miles in 2029. FBA white paper This growth is backed by actual capital spending. The four largest hyperscale cloud companies (Amazon, Microsoft, Google, and Meta) together spent roughly $113.4 billion on capital expenditures in the most recent quarter, up more than 73% from the same quarter a year earlier, and their combined 2025 capex is expected to approach $400 billion. Bisnow Google alone raised its 2025 capex guidance to between $91 billion and $93 billion. In Q3, about 40% of its technical infrastructure capex went to data centers and networking. Alphabet Q3 2025 earnings call

How does the federal government fund middle mile fiber for AI data centers?

The Infrastructure Investment and Jobs Act of 2021 created the Enabling Middle Mile Broadband Infrastructure Grant Program with $980 million in funding. Middle Mile NOFO Grants typically range from $5 million to $100 million per project, though there is no required maximum, and the federal share cannot exceed 70% of total project costs, so the applicant must provide a 30% match. NTIA Middle Mile FAQ

States, local governments, tribal governments, utilities (including electric cooperatives), telecommunications companies, nonprofits, and even private technology companies are all eligible to apply. NTIA Middle Mile FAQ The funded infrastructure must be middle mile, meaning it does not serve end users directly. It can include leased dark fiber, transport connectivity to data centers, and carrier-neutral submarine cable landing stations. NTIA Middle Mile FAQ

The NTIA awarded nearly $980 million in 2023, spreading it across 36 organizations in 40 states and territories. Those awards fund more than 12,500 miles of new middle mile fiber. BroadbandUSA Notable projects include

• Pima County, Arizona received $43 million to build a 134 mile open access fiber ring around greater Tucson and surrounding rural communities. BroadbandUSA
• Omaha Tribe of Nebraska received $36 million for 384 miles of new fiber, plus 100 miles of leased dark fiber and 34 miles of upgraded existing fiber. BroadbandUSA
• Quintillion received $89 million for a 960 mile subsea route plus 105 terrestrial miles in Alaska. NTIA, BroadbandUSA
• Zayo Group is building a 649 mile underground middle mile route from Dallas to El Paso in rural West Texas, with 28 access points serving 401 community anchor institutions. Zayo broke ground in April 2025, and the grant requires completion by December 2026. Zayo BAR Report

The scoring rubric awards up to 10 bonus points out of 100 if an applicant commits to open access, meaning it offers wholesale, nondiscriminatory access to the funded network at just and reasonable rates. NTIA Middle Mile FAQ Open access is not mandatory, but many grantees adopted it to improve their application score and to allow multiple ISPs to use the same fiber.

The larger $42.45 billion BEAD program is primarily for last mile broadband, but states may shift some BEAD funds to middle mile projects if those projects are essential to reaching unserved locations. FBA Middle Mile White Paper

The NTIA issued a limited Buy America waiver in 2023 for the middle mile program. It exempts certain transport electronics from domestic sourcing requirements, but the fiber optic cable itself is not exempt. Commerce Dept. waiver, FBA supply chain white paper, Corning capacity expansion, News analysis So grantees must buy American-made fiber, though they may import some network electronics.

What are the federal land permitting rules for fiber?

Much of the new long haul and middle mile fiber is trenched across public lands managed by the Bureau of Land Management (BLM) or the U.S. Forest Service (USFS). The MOBILE NOW Act, enacted in 2018, established a firm deadline. Any federal executive agency must grant or deny a duly filed application for a communications use right of way, easement, or lease within 270 days and notify the applicant. 47 U.S.C. § 1455(b)(3)

The BLM implemented that deadline in a 2024 final rule (43 CFR Part 2860) that also consolidates several older communications use regulations and sets cost recovery fee schedules. BLM Final Rule The rule clarifies that the roughly 6,000 miles of energy corridors administered by the BLM and the U.S. Forest Service (USFS), may be used for collocated fiber. BLM Final Rule The USFS applies a similar process under its Special Use Permit regulations (36 CFR Part 251) and has created a National Broadband Team and an online submission portal to handle the influx of fiber applications related to BEAD and other programs. All proposals must use the SF-299 common form and include a Plan of Development. USFS fiber optic page

The 270 day shot clock does not override the National Environmental Policy Act (NEPA). Any federal action that triggers an environmental review must complete that review before the right of way can be granted. A project that requires a full Environmental Impact Statement (EIS) can easily take two years or longer, often exceeding the 270 day shot clock. CEQ EIS timeline data, CEQ NEPA deadlines Even a shorter Environmental Assessment (EA) often stretches past a year. A 2024 law review article reported that some rural electric cooperatives have reported wait times of a year or more for USFS permit review even for projects on existing utility poles, and small ISPs report delays of 18 to 24 months or longer to replace copper with fiber. Harvard Journal on Legislation In one documented case, a BLM permitting process for a ReConnect-funded project added $800,000 in unanticipated costs. Harvard Journal on Legislation

A real world illustration is the Vero Fiber Networks Reno to Las Vegas Fiber Optic Project. That 450 mile underground dark fiber route required right of way grants from three BLM Districts, a USFS Special Use Permit, a Bureau of Reclamation Use Permit, and a State of Nevada authorization. BLM Preliminary Environmental Assessment BLM prepared a full Environmental Assessment. The project also needed nine inline amplifier buildings and followed U.S. Highways 50 and 95. BLM EA

Who is building the new long haul fiber for AI data centers?

The private sector is racing to deploy fiber ahead of demand. Two carriers, Lumen Technologies and Zayo Group, illustrate the scale.

Lumen Technologies said it will expand its U.S. intercity fiber network from 16.6 million fiber miles at the end of 2025 to 47 million fiber miles by the end of 2028, laying 34 million new miles. Lumen press release It sells custom network services under the brand Private Connectivity Fabric, which provides dedicated dark fiber, custom network architecture, and digitally activated services to enterprises and hyperscalers. Lumen PCF In 2024 alone, Lumen booked $5 billion in AI-related PCF sales, largely to hyperscale cloud companies, and disclosed an additional $7 billion in active sales discussions. PR Newswire, S&P Global Market Intelligence To build that capacity, Lumen signed a supply agreement with Corning for its next generation AI fiber and cable system. Lumen will install more than 22,000 route miles of Corning fiber, upgrading existing routes and creating over 20 new routes. S&P Global Lumen has also deployed 400G IP and Ethernet services to more than 70 data centers across 16 metro markets, with the ability to scale to 800G or 1.6T as needed. Light Reading

Zayo Group owns approximately 133,000 fiber route miles and 15 million fiber miles in North America. Zayo BAR Report It announced in January 2025 plans to build more than 5,000 new long haul route miles over five years, citing a forecast 2-6X increase in AI-driven demand by 2030. Zayo press release Zayo booked more than $1 billion in AI-related deals in 2024 and reported an additional $3 billion in active sales pipeline. Zayo press release Two new routes highlight its strategy.

• A 385 mile Chicago to Columbus fiber route, expected to finish in late 2026, with six new inline amplifier sites. Zayo press release, Zayo announcement
• A roughly 400 mile Columbus to Ashburn, Virginia, route that Zayo said will provide the lowest latency path from Chicago to Ashburn, home to the largest concentration of data centers in the world. Zayo

Zayo also has the 649 mile Dallas to El Paso middle mile project funded by the NTIA, described above.

Other notable private builds include

• Uniti Group signed a 20-year contract in 2021 with an unnamed hyperscale customer for a high strand count dark fiber route between Pittsburgh and Ashburn, Virginia. Uniti press release
• Global InterXchange (GIX) launched the first privately owned, carrier neutral dark fiber route across the Hudson River in two decades in July 2024, connecting 60 Hudson Street in Manhattan to 165 Halsey Street in Newark. GIX blog
• AT&T entered a multi year purchase agreement with Corning in 2024 for next generation fiber to support the expansion of AT&T’s fiber network. Corning NTIA comments

Hyperscalers themselves also own a large share of subsea fiber. Google, Meta, Microsoft, and Amazon together control about 71% of global subsea fiber capacity, 80% of trans Pacific bandwidth, and 90% of trans Atlantic capacity. Om Malik On land, they primarily lease dark fiber from carriers like Zayo and Lumen, but are signing ever larger long term deals. The largest long haul dark fiber deal in 2024 was an 864 fiber count purchase by a single hyperscaler, a dramatic increase from the pre AI era when average long haul orders ranged from 8 to 12 fibers. Om Malik, Zayo, Om Malik Today, hyperscalers routinely order 12 to 48 fiber pairs per route to secure route diversity and future capacity. Om Malik, Mordor Intelligence

How is the long haul dark fiber market changing?

The U.S. dark fiber network market was valued at approximately $1.18 billion in 2025 and is projected to reach $1.84 billion by 2031, growing at a 7.65% compound annual rate. Mordor Intelligence The metro segment holds the largest share, 64.58%, because carriers must interconnect dense clusters of data centers, small cells, and enterprise POPs within sprawling conurbations like Dallas Fort Worth and Northern New Jersey, while long haul is growing fastest at a 9.64% CAGR. Mordor Intelligence

Construction costs are rising. The national average for underground fiber construction is $16.25 per foot, while aerial construction averages nearly $6.49 per foot. Both figures increased by double digit percentages from 2023 to 2024, driven by labor scarcity and higher resin costs. Mordor Intelligence Labor accounts for more than two thirds of total construction spending, so projects in remote or tight labor markets can cost significantly more than the national average.

Optical technology is also advancing quickly. The industry standard for a single wavelength has moved from 100 Gbps to 400 to 600 Gbps, with 1.2 Tbps wavelengths in development. Corning analysis Lumen and Zayo both report having 400G across their networks. Lumen is also planning 800G and 1.6 Tbps services. Light Reading Meanwhile, new fiber cables have been announced with 3,456, 6,912, and even 16,000 strands per cable, far exceeding the 864 or 1,728 strands per cable used in earlier routes. FBA White Paper

These trends are reshaping the commercial model. Instead of buying lit bandwidth month to month, many hyperscalers now prefer to lease dark fiber on an IRU basis for 15 to 20 years. They install their own optical gear at each end, which gives them control over the fiber’s capacity and avoids per usage pricing. That shift has driven the surge in large strand count deals and is pushing carriers to build with excess capacity, sometimes leaving dark strands in place for future sales.

What does the FCC regulate about long haul fiber?

The Communications Act of 1934 makes it the duty of every common carrier engaged in interstate or foreign communication by wire or radio to furnish communication service upon reasonable request, and authorizes the FCC, after opportunity for hearing, to require carriers to establish physical connections with other carriers when the Commission finds it necessary or desirable in the public interest. 47 U.S.C. § 201(a) The Telecommunications Act of 1996 added specific interconnection duties for incumbent local exchange carriers. Pub. L. No. 104-104, § 251

In practice, the FCC has consistently declined to impose those Title II common carrier obligations on long haul backbone providers. An FCC Office of Plans and Policy working paper viewed the Internet backbone market as competitive, and the agency has not subjected it to mandatory interconnection or rate regulation. FCC OPP Working Paper No. 32, September 2000 The FCC’s recent rulemaking on IP interconnection (FCC 25-73, October 2025) focuses on the transition from legacy voice interconnection to IP based interconnection among local carriers, not on regulating data backbone networks. FCC NPRM FCC 25-73

This deregulatory approach means that long haul fiber providers set their own terms for dark fiber leases, IRUs, and lit services. The deals are private contracts, often highly negotiated between the carrier and the hyperscaler. For a developer of a new AI data center campus, there is no federal right to compel a backbone provider to bring fiber to the site. The developer must either persuade a carrier to build a lateral, build the lateral itself and seek voluntary interconnection, or locate where fiber already is. In competitive markets like Northern Virginia, carriers are actively building laterals. In less dense regions, future connectivity must be evaluated early in the site selection process.

What are the main obstacles to building new long haul fiber?

Several obstacles slow new fiber builds.

• Federal land permitting delays from NEPA and resource agency consultations persist, even with the 270 day shot clock. Projects on BLM or USFS land routinely take longer. Harvard Journal on Legislation
• Construction cost escalation driven by labor scarcity and materials inflation. Underground fiber costs have risen over 10 percent year over year, and labor availability is tight. Mordor Intelligence
• Supply chain lead times for high density fiber cable. Manufacturers like Corning are expanding capacity, but the surge in demand has stretched delivery schedules. The Buy America waiver for electronics eases one bottleneck but does not address fiber cable. Commerce Dept. waiver
• Private land rights of way can be time consuming to negotiate. Many routes require easements from hundreds of individual landowners, adding months or years to project timelines.

These challenges mean that projects that control their permitting risk and secure early supply agreements have an advantage. Developers who partner with established network operators that have existing ROW agreements and experienced permitting teams can move faster.

Key takeaways

• Long haul fiber demand is forecast to more than double by 2029, driven by hyperscaler AI capex of nearly $400B annually.
• The NTIA Middle Mile Program offers $980 million in grants with a 30% match requirement and optional open access scoring.
• Federal land permitting has a statutory 270 day shot clock, but NEPA environmental reviews remain the dominant source of delay. Expect 18 months or more for projects on BLM or USFS land.
• Carriers like Lumen ($5B in AI deals) and Zayo ($1B) are building tens of thousands of new route miles under long term dark fiber agreements, often on an IRU basis.
• The dark fiber market is shifting to much larger strand count deals (12 to 48 fiber pairs), giving hyperscalers control over their optical capacity for 15 to 20 years.
• Long haul backbone is not subject to FCC Title II rate or interconnection regulation, so connectivity is secured through private contract, not regulatory mandate.
• Construction costs are rising (underground $16.25 per foot) and labor accounts for two thirds of spend. Early supply agreements and experienced contractors matter.

Frequently asked questions

Q:What is the difference between long haul and middle mile fiber?

A:
Long haul fiber carries data across cities, states, and regions. Middle mile fiber connects regional internet hubs to the long haul backbone but does not reach the end user. NTIA Middle Mile FAQ

Q:Why do AI data centers need so much more fiber than traditional ones?

A:
AI data centers use GPU clusters that need roughly 10 times more optical fiber connections inside the building , with increased fiber density also needed for the links between buildings to synchronize training runs. FBA White Paper

Q:How much fiber will the U.S. need to build by 2029?

A:
The U.S. needs to add roughly 214 million fiber miles by 2029, more than doubling the current 159 million fiber miles, to reach a projected 373 million fiber miles. FBA White Paper

Q:What is the NTIA Middle Mile Program and who can apply?

A:
It is a $980 million grant program that funds middle mile infrastructure. States, local governments, tribes, utilities, telecom companies, nonprofits, and private tech companies can apply. Grants require a 30% match and awards are expected to range from $5 million to $100 million, though this range is not a required maximum. NTIA Middle Mile FAQ

Q:What is the 270 day shot clock for federal land permits?

A:
Under the MOBILE NOW Act, federal agencies must grant or deny a complete application for a communications use right of way within 270 days. It applies to BLM and USFS, but NEPA environmental review can extend the real timeline well beyond 270 days. 47 U.S.C. § 1455(b)(3)(A)

Q:Which companies are building the most long haul fiber for AI?

A:
Lumen and Zayo are the most visible. Lumen is expanding from 16.6 million to 47 million intercity fiber miles by 2028. Zayo plans 5,000 new route miles over five years. Both have billions in AI-related contracts. Lumen PCF, Lumen AI deals, Zayo press release

Q:What is an IRU and why do hyperscalers prefer dark fiber over lit bandwidth?

A:
An IRU (indefeasible right of use) is a long term lease of dark fiber, typically 15 to 20 years. Hyperscalers dominate dark fiber and subsea cable capacity, giving them control over their networks and allowing them to bypass carrier fees. Om Malik

Q:Does the FCC regulate long haul fiber interconnection or prices?

A:
No. The FCC has declined to apply Title II common carrier obligations to long haul backbone providers. Long haul fiber backbone interconnection and pricing are set by private contract. FCC working paper

Q:How much does underground long haul fiber construction cost?

A:
The national average is about $16.25 per foot for underground construction, compared to $6.49 per foot for aerial. Labor makes up over two thirds of that cost. Mordor Intelligence

Q:Can my new AI data center campus force a carrier to connect fiber to the site?

A:
No. There is no federal mandate that a backbone provider must extend fiber to a new site. You must either negotiate with a carrier, build your own lateral, or select a site that already has connectivity.

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Junde Liu, JD, LL.M. (Taxation) candidate at UF Law. Originally published on Compute Law Blog. This article is general information and does not constitute legal advice. Reading it does not create an attorney client relationship. The reader should not act on the basis of any content here without first consulting a licensed attorney in the relevant state. Last reviewed for accuracy May 23, 2026.