SpaceX’s Starlink Internet service can get around underwater cable breakage since it can send data packets between its satellite fleet.
Other satellite systems may eventually support this capability as well, reducing the negative effects of cable outages on Internet connectivity throughout the world.
There have been four undersea cable breakage along Africa’s west coast, however many South African roaming users of Starlink’s service have indicated that this has not affected their connections.
Midway through March 2024, a subsurface landslide is thought to have triggered the incident, which affected Internet access and occasionally created problems for numerous online services in South Africa and other African nations.
It resulted in a protracted suspension of mobile data services on Vodacom.
Although a lot of providers have redirected traffic to other routes, this has increased latency, and it is not anticipated that full capacity will be accessible until the cable breaks are repaired.
Unaffected Starlink Roaming in South Africa
There were no such issues reported by Starlink users in South Africa.
This is as a result of their data traffic being transferred between satellites and ground stations on the other side of the breaks rather of being routed through these cables.
The technology enabling these has been termed “space lasers” by the SpaceX crew, but in the satellite industry, it is formally known as Optical Inter-Satellite Links.
Despite not having invented intersatellite communication, Starlink boasts the largest fleet and most laser links of any operator.
“Lightwaves,” or the portion of the electromagnetic spectrum that includes visible, ultraviolet, and infrared light, are used by these networks to transfer data.
SpaceX president and chief operating officer Gwynne Shotwell recently announced that the business will begin selling the technology to other satellite internet providers due to its success.
Shotwell announced, “We are going to roll out a capability, we call it plug-and-plasers,” at a conference for the industry.
SpaceX engineer Travis Brashears stated in a January 2024 PCMag article that the system was delivering about 42 million gigabytes of data every day, with a peak capacity of 5.6 terabits-per-second (Tbps).
In late March of 2024, NAPAfrica, the largest Internet exchange point in South Africa, had a peak throughput of about 4Tbps, to put this into perspective.
A 100Gbps connection may be maintained by each laser link, allowing them to send 12.5GB of data every second. This can reach 200Gbps or 25GB/s per link at maximum speed.
The linkages exchange information reliably, averaging 266,141 “laser acquisitions” every day.
The longest known connection between two Starlink satellites was 5,400 kilometers as of this writing.
According to Brashears, Starlink has the ability to quickly and dynamically alter the paths that the laser links of its satellites take.
He used a presentation he had prepared to demonstrate how the laser links may use around seven distinct paths to send data to a Starlink dish in Antarctica.
“As long as we have some path to the ground, you’re going to have 99.99% uptime. That’s why it’s important to get as many nodes [satellites with laser links] up there as possible.”
Infrastructure On the Ground is Still Required
It is imperative to underscore that Starlink and other satellite-based broadband services are not capable of functioning in isolation from terrestrial infrastructure.
To do this, the data centers hosting the content of the Internet would need to be relocated to satellites orbiting the planet.
There will come a time when Starlink’s fleet must establish a connection with its ground stations.
These ground stations are already up and running, giving Starlink consumers latencies of less than 50 ms in many of the nations where the service has been formally launched.
Even though there will be extra latency, customers connecting to satellites far from ground stations can still access the Internet thanks to the Starlink satellite-to-satellite links.
This also applies to subscribers of Starlink roaming in South Africa, where SpaceX has not yet made an official launch.
While there is a ground station under construction in Mozambique that could greatly reduce latency, South African Starlink users now have to wait more than 100 ms to reach a Nigerian ground station.
Although there are more than 5,500 satellites in Starlink’s constellation, the ones equipped with space lasers were only added in September 2021.
This indicates that in nations without ground stations, their concentration is insufficient to match the latency of fiber.
Improved Latencies Over Fiber in the Future
But once more space laser-equipped satellites are in orbit, Starlink may eventually be able to outperform underwater cables in latency, according to calculations made by a professor of computer science.
Mark Handley, a professor of networked systems in the University College London Department of Computer Science, demonstrated how the laser links in Starlink’s constellation might reduce the round-trip latency between Johannesburg and London to 100 m
As it stands, using the fiber undersea cables that run along Africa’s west coast, the round-trip latency between these two locations is approximately 160 ms.
In a different scenario, Handley set up fictitious ground stations along a route between Johannesburg and London, in towns where there was at least one mosque.
He discovered that by bounce data from the user to satellite to ground station, then back to satellite and ground station, latency of 77 ms to 82 ms could be accomplished.
Handley estimated that steady latency might decrease to as little as 75 ms when using a combination of ground stations and laser connectivity.
It is anticipated that Starlink’s overall and satellite-to-satellite performance would significantly improve in the upcoming years.
Approximately 9,000 laser links are included in the current constellation.
The Federal Communications Commission has given the business permission to put 12,000 of its satellites into space, almost doubling the number of satellites it currently has.
In order to reach 42,000 satellites overall, it plans to launch an additional 30,000.
