South African gamers and esports professionals will be glad to know that SpaceX’s Starlink broadband Internet service could one day deliver better latency over long distances than fibre connectivity.
This is due to two key improvements which are expected to come to the service over the next few years – a higher number of ground station installations, and the addition of laser crosslinks between satellites.
The company recently opened pre-orders for the service in South Africa, providing the opportunity for interested persons to put down a $99 deposit to secure their Starlink Kit once the network goes live in the country in 2022.
Starlink has claimed that current beta users record download speeds in excess of 100Mbps and uploads of 20Mbps, in addition to less than 31ms latency for 95% of round-trip measurements.
The latter is particularly important for those looking to sign up for the service to play multiplayer games online.
While plenty of content and services available on the Internet are hosted in South Africa, gaming servers are few and far between.
South Africa does not have the sheer number of players to support local servers on all major titles at any given time, which means gamers often have to play on international servers based in Europe or the United States.
This is particularly true for Battle Royale games like PlayerUnknown’s Battlegrounds or Fortnite which require a large number of players than typical multiplayer titles.
Due to the servers being physically located a significant distance away from South Africa, there is a delay in the response time from when an action is carried out and it actually occurs in-game.
In highly competitive shooters and MOBAs, a few milliseconds can make all the difference in the outcome of a match.
This delay is known as latency, and not only impacts gaming, but can have an effect on critical online services which require immediate reaction.
This makes it difficult for serious local gamers to compete at a global level, as they effectively have to engage competitors on a delay.
How Starlink works
To understand how the latest developments could result in greatly reduced latency, it is important to first get a grasp on how exactly Starlink works.
Users get a kit that consists of a router, a long Ethernet cable, and a dish antenna that is placed on a roof or area with an open view of the sky.
This system is then used to connect to the Starlink satellite fleet.
Once online, the Starlink user’s requests are transmitted from the antenna to the optimal satellite, which then sends the data to a ground station.
The ground station is connected via a fibre connection with backhaul to the Internet.
The data is then fetched and transmitted along the same path back to the user, although it may use a different satellite based on the positioning at the time of the response.
One major issue with this approach is that Starlink cannot provide coverage in areas with no ground stations.
To solve this, Starlink is currently testing the use of laser crosslinks in a number of its satellites, which would allow for data transfers to hop between them.
This technique could offer significant advantages over the submarine fibre cables that are used for international Internet traffic.
Firstly, the speed of light is around 50% faster when travelling in a vacuum – such as that which surrounds the Starlink satellites – than when transmitted in the fibre optic glass of the cables.
Secondly, the vast network of thousands of Starlink satellites generally provides a more direct pathway for the connection from one continent to the next.
Using ground stations and lasers
Professor of Networked Systems in the Department of Computer Science of University College London Mark Handley provided an insightful video on how Starlink could offer better latency than fibre over great distances.
According to his calculations, round-trip latency between Johannesburg and London could be cut to 100ms with laser links between Starlink’s satellites.
This is opposed to the average of 164ms provided by fibre submarine cables running along Africa’s West coast.
The image below illustrates one of the possible routes on which the data transfer could travel using this technique.
In his simulations, Handley placed hypothetical ground stations in towns with at least one mosque observable from space on a pathway between Johannesburg and London.
He found that latency between 77ms-82ms could be achieved by bouncing data transfer from the user to satellite to ground station, then again to satellite and to ground station.
A combination of the laser links and ground relays would be ideal, however, offering more stable latency measuring between 75-77ms.
It should be emphasised that Handley’s analysis is based on the assumption that Starlink’s satellites and ground stations would be equipped with sufficient hardware to handle the advanced routing computations needed to direct communications on the best pathways.
It does not take into account what the impact would be if a certain satellite or ground station would go down, which could introduce significant jitter or packet loss.
The current experience of the service in gaming appears to be mixed, with many users reporting a stable connection while others are complaining of constant connection drops.
In certain instances, the latter appears to be more related to the router Starlink supplies than the network itself.
Below is the full video showing the case for the use of ground stations and/or laser in the Starlink network, as compiled by Mark Handley.