Are you interested in Starlink?

[Johand]

Very clever system it seems. From what I make of it, sounds like it's completely different from the cellphone cell structure we understand in that your signature is ignored if not remaining within x km of your location. At least I hope a few km.
Wouldn't be surprised if it changes a bit later on, sounds like a capacity protection measure.

Yes.Cellphone cells refer to a single tower. However - the way starlink works is you will always be jumping between satellites - you are not assigned to a single satellite because they are zipping by too fast So I don't think "cells" are a good description of what is going on -- SpaceX must put in place actual geofencing or similar technology in it.

 

[Johand]

I think that very little people understand the latency that Starlink promises?? I think Mybroadband need to do a feature with detailed information on the pros and cons of of Starlink.

Well the problem is it would be changing all the time So Starlink bounces you to the closest ground station and then it is fibre the rest of the way (currently). With more ground stations and in future laser satellite to satellite things will change a lot.

The TLDR however is that old space internet has terrible, terrible latency (I once had to work remotely on 1600 ms ping -- it was painful) and starlink will have latency based on as-the-crow-flies distance. The distance of geostationary satellites dictate latency for old satellite internet, but the physical surface distance dictate latency for Starlink.

 

[Geoff.D]

The distance of geostationary satellites dictate latency for old satellite internet, but the physical surface distance dictate latency for Starlink.

Plus an added amount for the fact that the link is "in the sky". So, unless the equivalent satellite path is much closer to the GC distance, the so-called benefit compared to a physical distance routing will not be as great as the proponents of this system are trying to make it out to be.

Then, the added processing and switching delays could easily chew up any advantages, especially when the system starts becoming overloaded. In the ned, my gut tells me the suckers in SA that fall for all of this based on the long haul international latency arguments are going to be massively disappointed.

on 1600 ms

GSO ping time is at best, 500 ms, more likely closer to 800 ms typically. Subtract that from 1600 ms and you end up with 800 ms of processing ping time. Unless these fancy systems do something super different, that will be the same delay present in their systems IF the routing becomes complicated.

 

[Johand]

Plus an added amount for the fact that the link is "in the sky". So, unless the equivalent satellite path is much closer to the GC distance, the so-called benefit compared to a physical distance routing will not be as great as the proponents of this system are trying to make it out to be.

Then, the added processing and switching delays could easily chew up any advantages, especially when the system starts becoming overloaded. In the ned, my gut tells me the suckers in SA that fall for all of this based on the long haul international latency arguments are going to be massively disappointed.

Yes. Until satellite laser-to-laser comes into effect international latency will be MORE than we currently have on fibre. If however they perfect the laser links AND route long-distance that way (without hopping onto closest ground station) then there might be latency improvements. But this technology is not yet rolled out to the current starlink satellites (except a couple in polar orbit) and it might just be easier or mandated by law to use ground stations. I can easily see governments forcing Starlink to route through domestic ground stations to enable interceptions (RICA) and similar.

 

[Brian_G]

But this technology is not yet rolled out to the current starlink satellites (except a couple in polar orbit) and it might just be easier or mandated by law to use ground stations.

Elon is a nice chap, but a businessman, I would bet on the easier / cheaper solution here, unless gaming etc. is a priority market for him.

 

[Geoff.D]

Actually, there are a few of us who have had insight into the total impact of the SKA on the use of the affected spectrum in SA. You do NOT want to know what that impact is!

 

[Johand]

Actually, there are a few of us who have had insight into the total impact of the SKA on the use of the affected spectrum in SA. You do NOT want to know what that impact is!

I love both projects and both projects push humanity forward. Hopefully, the impact can be mitigated enough so that it is not a real problem (but a compromise will degrade both SKA and Starlink service. )

Super long term it would be great to have a square kilometer array in outer space (possibly in orbit on the other side of the sun). It will require a lot of breakthroughs though (cheaper and more heavy lift capacity, high-speed space comms, space-bound supercomputers and the list goes on). Lots of potential if you don't have to deal with gravity, interference, geography etc.

 

[Brian_G]

Good to dream @Johand , nothing wrong with that. I'm sure that's how Elon started.

 

[Zeus07]

Wait and see is the wiser choice I guess, but that will also cause an even bigger delay if I wait and my crappy town never sees fiber.
I think I'll just have to take the gamble.

 

[elf_lord_ZC5]

Not interested in fighting with body corporate, to be able to put up a dish installation, so I pass.

 

[Foxhound5366]

I'd love to experiment with this, but I've got 200Mbps fibre for almost half the price ... so I'm not the target demographic unfortunately.

 

[ghostRgg]

I personally feel Starlink has the potential to solve our latency issues, we could be looking at 70-80ms to London from South Africa as an example. Provided the rollout goes smoothly.

 

[neoprema]

Just out of interest sake, say ICASA says no to Starlink (or any country does) how do they actually stop it? I assume they can block imports of the link equipment and/or make it illegal to use it? But that still wouldn't stop someone DHL'ing one in?

In my opinion they should NOT be asking local governments for their approval since it doesn't solve the problem of governments trying to control people's access to the Internet, when it should be a basic human right?

 

[ghostRgg]

Just out of interest sake, say ICASA says no to Starlink (or any country does) how do they actually stop it? I assume they can block imports of the link equipment and/or make it illegal to use it? But that still wouldn't stop someone DHL'ing one in?

In my opinion they should NOT be asking local governments for their approval since it doesn't solve the problem of governments trying to control people's access to the Internet, when it should be a basic human right?

What Starlink is asking for is licensing and agreements to put up base stations in the country and potentially lower the costing of the equipment. Since depending on what import fees are used, you could be looking at 40% more on the cost.

For Starlink to work locally it would need base stations on the ground, in South Africa in all the major cities.

 

[HavocXphere]

Zero interest. Fiber is cheap, fast and reliable

South Africa in all the major cities.

Not gonna work for those anyway...too much density = bandwidth from overhead sats split too many ways

 

[Geoff.D]

I personally feel Starlink has the potential to solve our latency issues, we could be looking at 70-80ms to London from South Africa as an example. Provided the rollout goes smoothly.

You are dreaming. The shortest route from SA to London is the great circle distance, to which you must add 2x the latency to get to the satellites plus an allowance for the larger GCD at the altitude of the satellites. That is the theoretical best you could achieve just due to the maths and physics.

 

[Geoff.D]

Just out of interest sake, say ICASA says no to Starlink (or any country does) how do they actually stop it? I assume they can block imports of the link equipment and/or make it illegal to use it? But that still wouldn't stop someone DHL'ing one in?

In my opinion they should NOT be asking local governments for their approval since it doesn't solve the problem of governments trying to control people's access to the Internet, when it should be a basic human right?

It is NOT just about the equipment. It is about violating international spectrum agreements and the laws of countries.
Plus in SA, there is the added SKA Act which is a serious matter.

 

[cantankerous]

Understanding latency a little better: Latency is the round trip time between your PC and the server you are connecting to. It's that plain and simple. So this varies (by at least microseconds) for any connection between any A and B location. There is no such thing as a fixed latency based on link type. It depends where you are and where you are connecting to.

So first things first, if you're wondering about latency - please be specific about from and to where. There are multiple factors to your perceived ("eyeball") latency:

Last mile Latency: This is from the nearest pop (and or) datacentre to your home - Typically 1-3ms in major metros and anything up to 15-20ms for those in secondary metros. This is the latency you see when you run a speedtest to a local server (usually hosted in your "home" datacentre). This is also the latency the destination server can experience back to it's main dc. Eg. A server hosted in Manchester, connecting to London Telehouse.

Terrestrial Backhaul latency: If you're in Cape Town and you're connecting to content in JHB, your traffic first leaves your home, goes to a DC, then on to JHB. The JHB<>CPT leg is anything between 16-21ms depending on the route your traffic takes.

Transit Latency: If you're connecting to a server in the EU, your traffic goes from your home, to a DC, to a transit provider, to a cable system's landing station (WACS, SAT3, EASSY etc), over the cable, to an international landing station (eg. London, Marseilles etc) and off to a Datacentre in the EU and on to those networks. This adds at least 140-150ms for London Telehouse on the shortest paths.

All of the above is based on physics. Light travels at a fixed speed through lengths of glass. The longer the path, the higher the latency. And then there's actual processing that happens at dozens of locations along the path, each of which adds a small amount of latency to the travel of a packet.

Now, looking at initial Starlink results, we've seen latencies of 23-35ms in US tests (client to nearest speedtest server). For now, there is very little satellite to satellite communication, so looking at the lowest results, we can assume that the last mile latency will always be a minimum of 25-30 (Client <> Satellite <> Ground station). This would be how long it takes for a signal to travel from a Starlink client dish to a satellite and (presumably) straight back down to a ground station which is linked to a Datacentre. So from this, we can infer that the round trip latency from the ground (client or ground station) to a Starlink satellite is 12-15ms and satellite to satellite comms will add to this, the same way terrestrial backhaul adds to this.

Starlink satellite to satellite communication is currently radio and will move to laser soon. For both of these mediums, the latency is identical (light travels at the speed of light, that simple), the benefit of laser is simply higher capacity. Given the lower altitude of the satellites means that should a long haul transit route be established satellite to satellite (ie, SA to London), this would need multiple satellite hops and a larger radius route. The fact that it is (hopefully) more direct, means it should be equal to or within a single digit percentage difference of submarine systems.

To understand this better, if Starlink wants to deliver on great latency in SA, it would need at least 3 ground stations (JHB, DBN, CPT) and the ability to determine which ground station is optimal for your location - which is not easy when your satellites move over the entire landmass of SA in a matter of minutes. IE, if you're in cape town, you would need to be routed to the cape town ground station, and in the north you're routed to a JHB ground station. And then you would probably pick up traffic via terrestrial backhaul, adding 16-21ms in addition to the 25-35ms. Remember, data and content is still sitting on earth and you need to pick it up from the nearest possible location.

Chances are, with only limited total capacity on each satellite, satellite to satellite communications for global traffic would be limited for special use, eg. financial markets and real time communications and at a significant cost (demand/supply). Most eyeball traffic will probably be routed to the closest regional ground station per country. Building multiple ground stations in each country with power, backhaul, transit, routers and more will be extremely expensive and frankly unnecessary for a small (geographic and customers) market like South Africa, so we'll likely see one or two be built.

 

[Geoff.D]

It will "never*" be possible to provide sufficient inter-satellite link capacity to route all but "essential**" traffic that way. Hence most traffic will still end up being routed to the nearest GS and then terrestrially.
* Never say never: so how many centuries and new technological developments will be required is any one's guess.
**Essential: is Joe Soap's internet searches essential? Is your gaming traffic essential? Probably not.
Don't be fooled by the current test phases, where the network proponents are in the BS phase of their product marketing campaigns.

 

[ghostRgg]

Chances are, with only limited total capacity on each satellite, satellite to satellite communications for global traffic would be limited for special use, eg. financial markets and real time communications and at a significant cost (demand/supply). Most eyeball traffic will probably be routed to the closest regional ground station per country. Building multiple ground stations in each country with power, backhaul, transit, routers and more will be extremely expensive and frankly unnecessary for a small (geographic and customers) market like South Africa, so we'll likely see one or two be built.

Not going to quote it all because that's one wall of text. My whole argument for the lower latency is based upon theoretical numbers and calculations as to what is possible given that it does the following for long backhaul transit.

User -> 380km Low Orbit satellite -> Backhaul Sattelite at 500-1100km -> around 5 hops over the transit satellites in the higher orbit. Given that the distance between Johannesburg and London is 9070km in a straight line distance. I will work out the actual orbital distance at 1000km when I have some time. So as an example im going to throw on 50% leeway so 9070*1.50 = 13605km distance.

Using the current speed of fibre it would cover that 13605 km in roughly ~138ms and that is with a 50% leeway on the distance, which might be somewhat more accurate than my previous calculations. Then if you going up and down 1000km each way that's 2000km which adds another 22ms. So total latency is 160ms from JHB to London. This includes a transit latency of 1ms per a satellite over around 5-6 hops.

I get that this is basically on par with current latency. I mean, if we managed to get a fibre path through Africa its 12,877km From Johannesburg via current African roads. Having a fibre backhaul here would give us 137ms (JHB -> London) and 117ms to Spain.

This is all assuming I am being a realist on how the tech will function and how there is a 99% chance it's useless for a low latency project like I am suggesting. But, hear me out. There is a chance.

Best Case Scenario for Starlink

Starlink as a backhaul provider from JHB Datacentre to London Datacentre.

I need to point out that Starlink is rolling out lasers as it will act as a major backhaul on inter-satellite connection, which lowers latency and the lasers actually are faster than fibre, don't forget that. Speed of light in space/vacuum. Light travels at 300,000 km/s in a vacuum, but when in glass it around 200,000 km/s. This means that it is technically 50% faster than what fibre would be. For the sake of SCIENCE, I would say we can assume it will be ~40% faster than current fibre optics in transition speed.

Johannesburg -> 380km Low Orbit satellite -> Backhaul Sattelite at 1100km -> around 8 hops over the transit satellites in the higher orbit. Given that the distance between Johannesburg and London is 9070km in a straight line. It would be around 13,000km given the extra distance of the satellites all not being in a line and the distance from the ground to orbit.

The latency on fibre over that distance would be 132ms with 1ms equipment latency.
On a laser backhaul (the 10,000km distance) it would be around 88ms + 22ms for the transit from the ground up, giving us a total latency from JHB - LONDON at around 110ms. Then your usual 2-5ms hop for the people in JHB and you can get a latency of 112-115ms.

Now another exciting point is the whole, a bunch of servers are located lower in Europe, such as Paris. Which is around 8728km at 20% leeway that's around 10473km = 106ms with 200 KM/millisecond fibre or 72ms with 299 KM/millisecond laser transit.

This is where I get excited.

Disclaimer: I am a crazy low latency person. But for interest sake, watch this video with a grain of salt.