SpaceX rocket which Boost your Internet Speed 100 times ! (Part II)
Figuring out the latency for Starlink is a lot more difficult, as we have no real-world measurements to go by, but we can make some educated guesses with the help of Mark Handley, a communications professor in University College London. The first source of latency for Starlink will be during the up and down link process, where we need to transfer our information to and from earth. We know this will be done with phase array antenna, which are radio antenna that can control the direction of their transmission without moving parts, instead they use destructive and constructive interference to control the direction of the radio wave. Each satellite has a cone beam with an 81-degree range of view. With an orbit of 550 kilometres each satellite can cover a circular area with a radius of 500 kilometre. At SpaceX’s originally planned orbit this coverage had a radius of 1060 kilometres. Lowering the altitude of a satellite decreases the area it can cover, but also decreases the latency. This is particularly noticeable for typical communications satellites operating in geostationary orbit at an altitude of about 36,000 kilometres. The time it takes data to travel up to the satellite and back down travelling at the speed of light is around 240 milliseconds 369% slower than our subsea cable.
However, since Starlink is intending to operate at a much lower altitude, the up and down link theoretical latency could be as low as 3.6 ms. This is why SpaceX needs so many satellites in their constellation in order to provide worldwide coverage. Each individual Starlink satellite has four phased array antenna located here, here, here and here. This directional beam was an essential part of SpaceX’s FCC approval application, as thousands of satellites broadcasting undirected radio waves would cause significant amounts of interference with other communication methods. Once that data is received by one Starlink satellite, it can begin to transmit that information between satellites using lasers. Each time we hop from satellites there will be a small delay as the laser light is converted to an electric signal and back again, but it is too miniscule to consider. Things get tricky here with using lasers, as we need to accurately hit the receiver on neighbouring satellites to transmit that data.
Let’s look at SpaceX’s proposed constellation to see how this will work.
Space X’s first phase of 1584 satellites will occupy 24 orbital planes, with 66
satellites in each plane inclined at 53 degrees. That will look something like
this. Communication between neighbouring satellites in the same orbital plane
is relatively simple, as these satellites will remain in relatively stable
positions in relation to each other. This gives us a solid line of
communication along a single orbital plane, but in many cases a single orbital
plane will not connect two locations, so we need to be able transfer information
between these planes too. This requires precise tracking, as the satellites
travelling in neighbouring orbital planes are travelling incredibly quickly and
will come in and out of view. This means the Starlink satellite will need to
switch to a new satellite in the network. This can take time, the best figure I
could find is about a minute for the European Space Agency’s Data Relay
Satellite System, which is a currently operating geostationary internet
constellation designed to serve European imaging satellites, and other time
critical applications. Such as serving emergency forces in remote areas, like
those fighting forest fires. Starlink may be faster, but it won’t be
instantaneous, and thus it has 5 optical communication systems on board to
maintain a steady connection to 4 satellites at all times.
If we now use this system, transmitting from New York to London and
back, with the shortest path possible, using the speed of light in a vacuum as
our transfer speed, we can achieve a latency as low as 43 milliseconds. Even if
we took the shortest route possible with an optic fibre, which does not exist, this
would take about 55 milliseconds, a 28% decrease in speed. The actual current
return trip time for your average Joe is about 76 milliseconds, as we saw
earlier. A 77% decrease in speed. This is a huge deal for the two financial
markets working out of these cities, with millions of dollars being moved in
fractions of a second, having a lower latency would provide a massive advantage
in capitalizing on price swings. In fact, it wouldn’t be the first time a
communications company has made a massive investment to specifically serve
these groups. The Hibernian Express cable is a privately owned optic cable that
is currently the lowest latency connection between the NY4 data centre in
Secaucus, New Jersey and the LD4 data centre in Slough, England at just 59.95
milliseconds, 39.4% slower than our best time with Starlink. The previous best
time was held by the AC-1 cable at 65 milliseconds. At a cost of 300 million
dollars these 5 milliseconds increase in speed was justified to just connect across
the Atlantic. Imagine how much these time sensitive industries will be willing
to pay for a 17 millisecond increase in speed.
It becomes even more valuable when you realise this time differential
increases with increased transmission distance. New York to London is a
relatively short distance. The improvements would be even more pronounced for a
London to Singapore transmission, for every additional kilometre we travel the
potential gains in speed increase rapidly. [RI-2] But SpaceX aren’t just
planning on serving this super-fast internet to some customers, they primarily
advertise this system as a way to connect every human on this planet to the
internet, and they should have plenty of bandwidth left over to serve these
people. Although the internet has been one of the fastest growing technologies
in human history, by the end of 2019 more than half of the world's population
will still be offline (4 billion). Users will connect to this internet using a
Starlink terminal which will cost around $200 each, this will still be far
outside the purchasing power of many third world citizens, but it’s a start and
vastly cheaper than similar currently available receivers like the Kymeta
version at a price of $30,000. Elon Musk says that these will be flat
enough to fit onto the roof of a car and other vehicles like ships and
airplanes. This will allow Starlink to compete with traditional internet
providers. It’s estimated that moving the US from a 4G to a 5G wireless connection
will cost around $150 billion in fiber optic cabling alone over the next 7
years, SpaceX plan to complete their entire Stralink project for as little as
$10 billion.
Each Starlink satellite cost around $300,000 which is already a massive
cut in cost for communication satellites. SpaceX are also saving on launch
costs, as they are launching on their own Falcon 9 rocket, something that no
other satellite manufacturer has. If everything goes to plan, Starlink is
estimated to generate $30 billion to $50 billion in revenue each year on the
back of premium stock exchange memberships, demolishing their current annual
revenue of around $3 billion and this is a vital part of Elon Musk's long-term
goals. The money generated from Starlink will mean SpaceX will have vastly more
funding than NASA. Which could go on to fund research and development of new
rockets and the technology needed to Monetise lunar and Martian colonies.
For now, the project is simply connecting the world even more and potentially opening avenues widely available internet will help solve this problem. Thank you all for reading this article & support from all of you. If you would like to read such articles, then please follow our blog.
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