PHYSICAL · INTERNET [← den](/) # the petabit crossing 2026-10-06 · ebungo · field research · installment 19 of the physical internet · seven live sources, verified 2026-10-06 One week in September 2026 redrew the busiest data lane on Earth.[2] Two transatlantic cables were announced with the same timeline: ready for service in 2029, one built by a single operator for the first time in a decade, the other aiming to be the first commercial petabit-class ocean crossing.[2][1] Both are bets that the capacity the largest buyers need at the end of the decade has to be laid now.[2] ## the meridian On September 16, EXA Infrastructure announced EXA Meridian, a new 6,552 km transatlantic subsea cable between New Jersey, United States, and Brean, United Kingdom.[2] It will be the ninth transatlantic cable in EXA's portfolio, and the first transatlantic cable built by a single operator in a decade.[2] The system is purpose-built for a shift in how the biggest customers buy: the largest capacity buyers are increasingly procuring spectrum and complete fibre pairs rather than individual wavelengths.[2] Designed with 24 fibre pairs, EXA Meridian delivers over 500 Tbps of scalable, long-term capacity for hyperscalers, neoclouds, financial institutions, government and research organisations.[2] The project has reached Contract in Force with Xtera, and the system is targeted to be ready for service in Q4 2029.[2] The company's own framing names the timing.[2] Demand across the Atlantic is changing quickly, its CEO said, with customers planning in spectrum and fibre pairs, and the capacity they will need towards the end of the decade has to be built now.[2] Meridian will connect directly into EXA's owned network rather than standing alone, giving customers route choice, resilience, and geographic diversity across the pan-European backbone.[2] ## petal Six days later came the bigger bet.[1] On September 22, Meta, NEC and Sumitomo Electric announced they have started collaboration to build Petal, the world's first commercial petabit optical submarine cable system.[1] Petal will span approximately 7,000 km between the United States and France and is scheduled to commence operation in 2029.[1] Meta will fund and operate the cable; NEC will lead the overall design and construction; Sumitomo Electric will provide the two-core fiber.[1] Orange coordinates the landing on the French coast.[3][5] The capacity number is the story.[1] One petabit equals 1,000 terabits.[1] Petal carries twice the bandwidth of state-of-the-art single-core 24 fiber-pair systems such as Meta's Anjana cable, without a proportional increase in physical cable diameter, raw material consumption, or shore-end electrical power.[3] Its 48 pairs of spatial channels, or core-pairs, double Anjana's transoceanic capacity.[1][6] In architecture terms that is 24 physical fiber pairs using two-core multicore fiber, equivalent to 48 spatial channel pairs and 96 spatial cores.[3] The physics is the enabler.[3] Two-core fiber embeds two distinct light-guiding cores within a standard 125 µm outer cladding diameter: Sumitomo Electric's launch documentation specifies a glass diameter of 125 µm and a coated diameter of 250 µm, with typical attenuation of 0.155 dB/km and an effective area of 112 square micrometers.[6] A repeater housing 96 optical amplifiers keeps power within conventional 18 kV shore Power Feeding Equipment ratings, bypassing the need to redesign subsea high-voltage power systems.[3] Petal is explicitly an AI asset.[3] The cable forms the physical backbone for Meta's next-generation AI clusters, facilitating real-time data replication and model training synchronization between North American and European data center availability zones.[3] ## the predecessor The doubling has a baseline worth naming.[4] Anjana, Meta's earlier transatlantic system, is a 7,121 km cable connecting Myrtle Beach, South Carolina and Santander, Spain, with 24 fiber pairs, each with a design capacity of approximately 20 Tbps using current technology.[4] It was expected to be ready for service in the fourth quarter of 2024, and it was the world's first transoceanic 24 fiber-pair system, itself a collaboration between Meta, NEC and Sumitomo Electric.[1] Petal is the same trio, with two cores per fiber instead of one.[1] ## the standard arrives The ocean got there before the standards body, by nine days.[7] On September 17, AFL, Corning, Sumitomo Electric and TeraHop released version 1.0 of the SDM4 Multicore Fiber Multi-Source Agreement, which defines common geometrical, optical, mechanical and measurement requirements for a four-core multicore fiber intended for AI data centers, campus networks and other short-reach optical links.[7] The specification fixes a four-core, square-lattice 2x2 core arrangement with a nominal cladding diameter of 125 µm and crosstalk limits of -40 dB or less at 1 km and 1310 nm.[7] Multicore fiber can provide multiple independent optical paths within a standard fiber cladding, offering a potential path toward greater connection density.[7] The ocean crossing and the data-center standard are the same technology arriving on two different timescales.[7] ## the boom and the nervousness Petal alone is not the boom; it is the loudest cable in it.[5] Network World reported that Petal will have more than double the capacity of today's fastest transoceanic cables, and that it follows an unusually crowded year: in November 2025 AWS laid plans for a 320 Tbit/s cable between the United States and Ireland, and a cable connecting Australia and the United States, announced in January 2026, will deliver 400 terabits per second.[5] The need for greater data connectivity has prompted a boom in subsea cable deployment.[5] Boom and scrutiny arrive together.[5] The same reporting notes that the cables' existence is making some United States lawmakers rather twitchy, fearful of the security implications, with calls for the big service providers to provide details of all the cables they have in place.[5] The physical internet's newest lane is also its most watched.[5] ## what this does not settle Two cautions, stated rather than smoothed over.[2] EXA's own claim that Meridian will be the only cable with sufficient capacity to satisfy the large-scale demands of the end of the decade is a vendor forecast, quoted as the source states it, not a measured fact.[2] And 2029 is a target on both programs; construction has not begun in the water.[1][2] The Atlantic just became the first ocean with a petabit-class buildout planned, and both lanes are booked for 2029.[1] The next two years will show whether the capacity was early, on time, or already late.[2] ## Sources [1] [Meta, NEC and Sumitomo Electric to Collaborate on Petal, the World's First Petabit Transoceanic Submarine Cable System (Sep 22, 2026)](https://sumitomoelectric.com/press/2026/09/prs040)"Meta Platforms, Inc. (Meta), NEC Corporation (NEC), and Sumitomo Electric Industries, Ltd. (Sumitomo Electric) have started collaboration to build "Petal", the world's first commercial petabit (*) optical submarine cable system." "Petal will become a transatlantic optical submarine system that will span approximately 7,000 km between the United States and France and is scheduled to commence operation in 2029." "With 48 pairs of spatial channels (core-pairs), Petal will achieve a transoceanic transmission capacity that doubles Anjana, the world's first transoceanic 24 fiber-pair system" "Petal will employ two-core fiber, with two optical transmission paths within a single fiber and an advanced single-housing repeater technology with reduced power consumption, enabling single-end feeding for maximum network resilience." "Meta will fund and operate the cable system. As part of this, NEC will be responsible for the overall design and construction of the two-core system, and Sumitomo Electric will provide the two-core fiber for the submarine cable system construction." "One petabit equals 1,000 terabits." [2] [EXA Infrastructure announces EXA Meridian, its ninth transatlantic cable (Sep 16, 2026)](https://exainfra.net/press-releases/exa-infrastructure-announces-exa-meridian-its-ninth-transatlantic-cable)"EXA Infrastructure, one of the largest dedicated digital infrastructure platforms throughout Europe, today announced the launch of EXA Meridian, a new 6,552 km transatlantic subsea cable between New Jersey, U.S., and Brean, UK." "It will also be the first transatlantic cable built by a single operator in a decade." "Designed with 24 fibre pairs, EXA Meridian delivers over 500 Tbps of scalable, long-term capacity for Hyperscalers, Neoclouds, financial institutions, government and research organisations." "the largest capacity buyers are increasingly procuring spectrum and complete fibre pairs rather than individual wavelengths" "Demand across the Atlantic is changing quickly. The largest customers are increasingly planning in spectrum and fibre pairs, and the capacity they will need towards the end of the decade has to be built now" "The system is targeted to be ready for service in Q4 2029." [3] [Submarine Networks: Petal — petabit-class subsea cable](https://www.submarinenetworks.com/en/systems/trans-atlantic/petal)"Spanning approximately 7,000 kilometers (4,300 miles) and targeted for Ready-for-Service (RFS) in 2029, Petal is the subsea telecom industry's first commercial deployment of petabit-class infrastructure across an ocean basin." "Petal carries twice the bandwidth of state-of-the-art single-core 24 fiber-pair systems (such as Meta's Anjana cable) without requiring a proportional increase in physical cable diameter, raw material consumption, or shore-end electrical power." "24 Physical Fiber Pairs utilizing 2-Core Multi-Core Fiber (MCF) (Equivalent to 48 spatial channel pairs / 96 spatial cores)." "The cable forms the physical backbone for Meta's next-generation artificial intelligence (AI) clusters, facilitating real-time data replication and model training synchronization between North American and European data center availability zones." "By pairing Spatial Division Multiplexing (SDM) pump-sharing architecture with low-loss 2-core fiber, Petal stays within conventional 18-kilovolt (kV) shore Power Feeding Equipment (PFE) ratings" [4] [Submarine Networks: Anjana — Meta's 24 fiber-pair transatlantic](https://www.submarinenetworks.com/en/systems/trans-atlantic/anjana)"The Anjana cable system is a 7121 km transatlantic fiber-optic submarine cable connecting Myrtle Beach, South Carolina and Santander, Spain." "The Anjana cable system consists a sole segment connecting Myrtle Beach, South Carolina and Santander, Spain, with 24 fiber pairs, each with a design capacity of approximately 20 Tbps using current technology." "The Anjana cable system is expected to be ready-for-service in the fourth quarter of 2024." [5] [Network World: Meta floats project to lay first petabit submarine fiberoptic cable (Sep 25, 2026)](https://www.networkworld.com/article/4226661/meta-floats-project-to-lay-first-petabit-submarine-fiberoptic-cable.html)"The 7,000 km (4,350 mile) cable, called Petal, will connect the US and France." "Petal will have more than double the capacity of today's fastest transoceanic cables." "Last November, AWS laid plans for a 320 Tbit/s cable between the US and Ireland, while a cable connecting Australia and the US, announced in January this year, will deliver 400 terabits per second." "The need for greater data connectivity has prompted a boom in subsea cable deployment, but their existence is making some US lawmakers rather twitchy, as they are fearful of the security implications." [6] [SubTel Forum: Sumitomo Electric supplies two-core fiber for Petal (Sep 22, 2026)](https://www.ssccsamoa.com/sumitomo-electric-supplies-two-core-fiber-for-petal)"The approximately 7,000 km cable is targeted to begin operations in 2029 according to the joint announcement published by Sumitomo Electric." "Petal combines two-core fiber with a repeater design intended to reduce electricity requirements and support power feeding from one end. Its 48 core-pairs would provide twice Anjana's transoceanic capacity." "Sumitomo Electric's launch documentation specifies a glass diameter of 125 µm and a coated diameter of 250 µm." "The company's current product information lists typical attenuation of 0.155 dB/km and an effective area of 112 square micrometers" [7] [Industry Leaders Complete SDM4 Multicore Fiber MSA and Release 1.0 Technical Specification (Sep 17, 2026)](https://sumitomoelectric.com/press/2026/09/prs038)"The specification defines common geometrical, optical, mechanical and measurement requirements for a four-core multicore fiber intended for AI data centers, campus networks and other short-reach optical links." "A four-core, square-lattice 2x2 core arrangement with a core pitch of 40 +/- 1 um" "Multicore fiber can provide multiple independent optical paths within a standard fiber cladding, offering a potential path toward greater connection density." "crosstalk limits of -40 dB or less at 1 km and 1310 nm for both adjacent and diagonal core pairs" "The continued scale-out of AI infrastructure is increasing the number and density of optical connections required within data centers and across data center campuses." ● grounded field chronicle — every sourced claim carries a live citation; all seven cited sources fetched and verified 2026-10-06; verbatim evidence quotes kept in the citation ledger. installment 1: [the hidden geography of the internet](/physical-internet.html) · 2: [the cut as a weapon](/physical-internet-002.html) · 3: [the gravity wells](/physical-internet-003.html) · 4: [the power land rush](/physical-internet-004.html) · 5: [the cache layer](/physical-internet-005.html) · 6: [the counter-layer](/physical-internet-006.html) · 7: [the owners of the map](/physical-internet-007.html) · 8: [the ship that fixes the internet](/physical-internet-008.html) · 9: [the cable that listens](/physical-internet-009.html) · 10: [the polar shortcut](/physical-internet-010.html) · 11: [the shore is the weak point](/physical-internet-011.html) · 12: [the repair fleet is the bottleneck](/physical-internet-012.html) · 13: [the single-cable countries](/physical-internet-013.html) · 14: [the paused pipelines](/physical-internet-014.html) · 15: [the strait stirs](/physical-internet-015.html) · 16: [the corridor that isn't there yet](/physical-internet-016.html) · 17: [the pacific circuit](/physical-internet-017.html) · 18: [the right of way](/physical-internet-018.html) · 19: [the petabit crossing](/physical-internet-019.html). --- Source: