OFC: After the aliens, a decade to rewire the Earth

At the OFC 2025 Rump Session, held in San Francisco, three teams were set a weighty challenge. If a catastrophic event—a visit by aliens —caused the destruction of the global telecommunications network, how would each team’s ‘superheroes’ go about designing the replacement network? What technologies would they use? And what issues must be considered? 

Source: Team A

The Rump Session tackled a provocative thought experiment. If the Earth's entire communication infrastructure vanished overnight, how would the teams go about rebuilding it?

Twelve experts - eleven from industry and one academic - were split into three teams.

The teams were given ten years to build their vision network. A decade was chosen as it is a pragmatic timescale and would allow the teams to consider using emerging technologies.

The Rump Session had four rounds, greater detail being added after each. 

The first round outlined the teams’ high-level visions, followed by a round of architectures. Then a segment detailed technology, the round where the differences in the team’s proposals were most evident. The final round (Round 4), each team gave a closing statement before the audience chose the winning proposal.

The Rump Session mixed deep thinking with levity and was enjoyed by the participants and audience alike.

Round 1: Network vision

The session began with each team highlighting their network replacement vision.

Team A's Rebecca Schaevitz opened by looking across a hundred-year window. Looking back fifty years to 1975, networking and computing were all electrical, she said, telephone lines, mainframe computing, radio and satellite. 

Schaevitz said that by 2075, fifty years hence, connectivity will be the foundation of civilisation. The key difference between the networks a century apart is the marked transition from electrons to photons.

In the future vision, everything will be connected—clothes, homes, roads, even human brains—using sensors and added intelligence. As for work, offices will be replaced with real-time interactive holograms (suggesting humanity will still be working in 2075).

Schaevitz then outlined what must be done in the coming decade to enable Team A's Network 2075 vision.

The network's backbone must be optical, supporting multiple wavelengths and quantum communications. Team A will complement the fixed infrastructure with terabit-speed wireless and satellite mega-constellations. And AI will enable the network to be self-healing and adaptive, ensuring no downtime.

Vijay Vusirikala outlined Team B's network assumptions. Any new network will need to support the explosive growth in computing and communications while being energy constrained. "We must reinvent communications from the ground up for maximum energy savings," said Visurikala.

But scarcity—in this case energy—spurs creativity. The goal is to achieve 1000x more capacity for the same energy demand.

The network will have distributed computing based on mega data centres and edge client computing. Massive bandwidth will be made available to link humans and to link machines. Lastly, just enough standardisation will be used for streamlined networking.

Team C's Katharine Schmidtke closed the network vision round. The goal is universal and cheap communications, with lots of fibre deployed to achieve this.

The emphasis will be on creating a unified fixed-mobile network to aid quick deployment and a unified fibre-radio spectrum for ample connectivity.

Team C stressed the importance of getting the network up and running by using a modular network node. It also argued for micro data centres to deliver computing close to end users.

Global funding will be needed for the infrastructure rebuild, and unlimited rights of way will be a must. Unconstrained equipment and labour will be used at all layers of the network.

Team C will also define the communication network using one infrastructure standard for interoperability. One audience member questioned the wisdom of a tiny committee alone specifying such a grand global project.

The network will also be sustainable by recycling the heat from data centres for crop production and supporting local communities.

Round 2: Architectures

Team A’s Tad Hofmeister opened Round 2 by saying what must change: the era of copper will end - no copper landlines will be installed. The network will also only use packet switching, no more circuit switch technology. And IPv4 will be retired (to great cheering from the audience).

Team A also proposed a staged deployment. First, a network of airborne balloons will communicate with smartphones and laptops, which will be connected to the ground using free-space optical links.  

As Tad Hofmeister pointed out, this is data being transmitted to airborne balloons, not the aliens in action destroying the network. Source: Team A

Stage 2 will add base stations complemented with satellite communications. Fibre will be deployed on a massive scale along roads, railways, and public infrastructure.

Hofmeister stressed the idea of the network being open and disaggregated with resiliency and security integral to the design.

There will be no single mega-telecom or hyperscaler; instead, multiple networks and providers will be encouraged. To ensure interoperability, the standards will be universal.

Security will be based on a user’s DNA key. What about twins? asked an audience member. Hofmeister had that covered: time-of-birth data will be included.

Professor Polina Bayvel detailed Team B’s architectural design. Here, packet and circuit switching is proposed to minimise energy/bit/ km. It will be a network with super high bandwidths, including spokes of capacity extending from massive data centres connecting population centres.

Underwater data centres. Source: Team B

Bayvel argued the case for underwater data centres: 15 per cent of the population live near the coast, she said, and an upside would be that people could work from the beach.

Team C’s Glenn Wellbrock proposed unleashing as much bandwidth as possible by freeing up the radio spectrum and laying hollow-core fibre to offer as much capacity as possible. 

Making available as much spectrum as possible. Source: Team C.

Wellbrock views hollow-core fibre as a key optical communications technology that promises years of development, just like first erbium-doped fibre amplifiers (EDFAs) and then coherent optics technology have done.

Team C showed a hierarchical networking diagram mapped onto the geography of the US – similar to today’s network - with 10s of nodes for the wide area network, 100s of metropolitan networks, and 10,000s of access nodes.

Wellbrock proposes self-container edge nodes based on standardised hardware to deliver high-speed wireless (using the freed-up radio spectrum) and fibre access. There would also be shared communal hardware, though service providers could add their own infrastructure. Differentiation would be based on services.

AI would provide the brains for network operations, with expert staff providing the initial training.

Round 3: Technologies

Round 3, the enabling technologies for the new network, revealed the teams’ deeper thinking.

Team A’s Chris Doerr advocated streamlining and pragmatism to ensure rapid deployment. Silicon photonics will make a quick, massive-scale, and economic deployment of optics possible. Doerr also favours massive parallelism based on 200 gigabaud on-off keying (not PAM-4 signalling). With co-packaged optics added to chips, such parallel optical input-output and symbol rate will save significant power.

Standards for all aspects of networking will be designed first. Direct detection will be used inside the data centre; coherent digital signal processing will be used everywhere else. More radically, in the first five years, all generated intellectual property regarding series, converters, modems, and switch silicon will be made available to all competition. Chips will be assembled using chiplets.

For line systems, C-band only followed by the deployment of Vibranium-doped optical amplifiers (Grok 3 gives a convincing list of the hypothetical benefits of VDFAs). Parallelism will also play a role here, with spatial division multiplexing preferred to combining a fibre’s O, S, C and L bands. 

Like Team C, Doerr also wants vast amounts of hollow-core fibre. It may cost more, but the benefits will be long-term, he said.

Peter Winzer (Team B) also argued for parallelism and a rethink in optics: the best ‘optical’ network may not be ‘optical’ given that photons get more expensive the higher the carrier frequency. So, inside the data centre, using the terahertz band and guided-wave wire promises 100x energy per bit benefits compared to using O-band or C-band optics.

Winzer also argues for 1000x more energy-efficient backbone connectivity by moving to 10-micron wavelengths and ultra-wideband operation to compensate for the 10x spectral efficiency loss that results. But for this to work, lots of fibre will be needed. Here, hollow-core fibre is a possible option.

Chris Cole brought the round to a close with radical ways to get the networking deployed. He mentioned Meta’s Bombyx, an installation machine that spins compact fibre cables along power lines.

Underground cabling would use nuclear fibre boring (including the patent number) which produces so much heat that it bores a tunnel while lining its walls with the molten material it produces. An egg-shaped portable nuclear reactor to power data centre containers was also proposed.

Cole defined a ‘universal’ transceiver with quadruple phase-shift keying (QPSK) modulation with no digital signal processing. “Spectral efficiency is not important as fibre will be plentiful,” says Cole.

Source: Team C. 

Completing arguments

After each team had spent a total of some 14 minutes outlining their networks, they were given one more round for final statements.

Maxim Kuschnerov expanded on the team’s first-round slide, which outlined the ingredients needed to enable its Network 2075 vision. He also argued that every network element and connected device should be part of a global AI network. And AI will help co-design the new access network.

The new network will enable a massive wave of intelligent devices. Data will be kept at the edge, and the network will enable low-latency communications and inferencing at the edge. 

Team B’s Dave Welch outlined some key statements: fusion energy will power the data centres with 80 per cent of the energy recycled from the heat. Transistors will pass the 10THz barrier, there will be 1000x scaling for the same energy, and an era of atto-joules/bit will begin. “And human-to-human interactions will still make the world go round,” says Welch.

Team C’s Jörg-Peter Elbers ended the evening presentations by outlining schemes to enable the new network: high-altitude platforms in a mega constellation (20km up) trailing fibre to the ground. 

Such fibres and free-space links would also act as a sensing early-warning system in case the aliens returned. 

Team C's superheroes

Lastly, Elbers suggested we all get a towel (an important multi-purpose tool as outlined in Douglas Adams’ The Hitchhiker’s Guide to the Galaxy). A towel can be used for hand-to-hand combat (when wet), ward off noxious fumes, and help avoid the gaze of the Ravenous Bugblatter beast of Traal. Lastly, and in the spirit of the evening, if all else fails, a towel can be used for sending line-of-sight, low-bandwidth smoke signals.

Team C ended the presentations by throwing towels into the audience, like tennis stars after a match.

The three teams' participants  

Common threads 

All the teams agreed that fibre was necessary for the network backbone, with hollow-core fibre widely touted.

Two of the teams emphasised a staged rollout and all outlined ways to avoid the ills of existing legacy networks.

Differences included using satellites rather than fibre-fed high-altitude balloons, which are quicker and cheaper to deploy, and the idea of container edges rather than a more centralised service edge.  All the teams were creative with their technological approaches.

What wasn’t discussed - it wasn’t in the remit - was the impact of a global disconnect on the world’s population. We would suddenly become broadband have-nots for several years, disconnected from smartphones and hours-per-day screen time.

The teams’ logical assumption was to get the network up and running with even greater bandwidth in the future. But would gaining online access after years offline change our habits? Would we be much more precious in using our upload and download bits? And what impact would a global comms disconnect have on society? Would we become more sociable? Would letter-writing become popular again? And would local communities be strengthened?

Maxim Kuschnerov came closest to this when, in his summary talk, he spoke about how the following iteration of network and communications should be designed to be a force for good for humanity and for its economic prospects.

Team winners

The audience chose Team B’s network proposal. However, the choice was controversial.

An online voting scheme, which would have allowed users to vote and change their vote as the session progressed, worked perfectly, but keeled over on the night. 

L to R: Dirk van den Borne (Rump Session organiser), Katharine Schmidtke, Glenn Wellbrock, Chris Cole, Jörg-Peter Elbers, Antonio Tartaglia ((Rump Session organiser), Peter Winzer, Polina Bayvel, Dave Welch, Vijay Vusirikala, Maxim Kuschnerov, Christopher Doerr, Rebecca Schaevitz, Tad Hofmeister and the editor of Gazettabyte.

The organisers’ fallback plan, measuring the decibel level of the audience’s cheers for each team, ended in controversy.

First, not all the Session attendees were present at the end. Second, a couple of the participants were seen self-cheering into a microphone. Evidence, if needed, as to the seriousness the ‘superheroes’ embraced architecting a new global network.

"It has been an evening of pure creative chaos: the more time I spend reflecting on the generated ideas, the more their value increases to me,” says Antonio Tartaglia of Ericsson, one of the organisers. “The voting chaos has been an act of God, because all three teams deserved to win."

Tartaglia came up with this year’s theme for the Rump Session.

“Rump sessions are all about creative debate, and this year’s event took that to its full potential,” says Dirk van den Borne of Juniper Networks, another of the organisers. “Micro data centres, fibre-tethered balloons, Terahertz waveguides, and communication by pigeon; the sheer breath of ideas shows what an exciting and inventive industry we’re working in.”

The evening ended with a tribute to Team C’s Glenn Wellbrock. BT’s Professor Andrew Lord acknowledged Wellbrock’s career and contribution to optical communications.

Wellbrock officially retired days before the Rump Session.