mspohr
Well-Known Member
We have working mobile Internet in some places but most of the earth's surface is not covered by existing networks. The satellite network would cover everywhere with high speed Internet.
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Uh, Matias....
I'll avoid the situation re Alaska. Right here in our winter home in Wickenburg, Arizona - where Tesla has a Supercharger!!!!!!! - there is zippidy-nada-doo-dah coverage. And the corridor between the Phoenix metro area and southern & central California is one of the most actively-used routes for all Model Ss.
The coverage gap here is quite extensive. And, as a real example, go back and look at my first post in this thread - #2 or so. Tesla COULD NOT remotely unlock my Model S a few days ago, right in downtown W'burg, because of the lack of connectivity.
This very definitely is not a situation of a non-problem looking for an answer. It is a real, present-time problem!
I'll avoid the situation re Alaska. Right here in our winter home in Wickenburg, Arizona - where Tesla has a Supercharger!!!!!!! - there is zippidy-nada-doo-dah coverage. And the corridor between the Phoenix metro area and southern & central California is one of the most actively-used routes for all Model Ss.
The coverage gap here is quite extensive. And, as a real example, go back and look at my first post in this thread - #2 or so. Tesla COULD NOT remotely unlock my Model S a few days ago, right in downtown W'burg, because of the lack of connectivity.
This very definitely is not a situation of a non-problem looking for an answer. It is a real, present-time problem!
mspohr
Well-Known Member
Existing mobile networks are only built where there are "enough customers"... that's the problem.
I live in an area where there are "enough customers" but I often travel to areas where there aren't enough customers... but I still need Internet.
Canuck
Well-Known Member
Canada (9,984,670 km²) is 29.5 times as big as Finland (338,419 km²).
I'm leaving soon to drive home from my cabin in Tulameen, BC to South Surrey, BC. -- 300 km through 2 mountain passes with only cellular coverage briefly while I pass through Princeton and then again when I get to Hope BC (where Tesla put 6 Superchargers that have been sitting for waiting for BC Hydro for over 2 months now to connect power to. Damn you BC Hydro! -- but I digress).
I'd love satellite internet and this is why I really like satellite radio. Maybe much of the world lives close together in highly populated areas (including me) but there are many who don't and there are also lots of us who get out to places with no cellular coverage on a regular basis.
On a recent cruise, I paid $250US to just to have internet for 7 days! (I needed it to connect to the office and as a business expense it's easier to justify).
PS. I'm writing this on government subsidized internet to rural areas in BC. I have a "dish" that points to a tower on a mountain across the lake. When I first bought here in 2005 it was dial-up only! The government subsidizes "China Creek Internet" 50% per client -- otherwise no company would be providing internet to rural BC. This is done on the basis that education, business, fire, safety, etc. are heavily reliant on the internet so having internet in rural BC is good for social issues and the economy and thus the government has stepped in until it makes economic sense for the free market to take over. China Creek has about 25 towers around BC that are powered by solar panels on remote mountain tops strategically placed to allow for line of site views from many areas.
Welcome To China Creek Internet
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There aren't many Model S owners in Montana but they're still building Superchargers there.
green1
Active Member
There aren't many customers in any one dead area, hence why they are still dead areas and nobody has paid to put up the infrastructure to cover them (if you have a couple thousand people in a few km radius you know someone will build infrastructure there), however with a constellation of satellites you aren't covering one dead area, you're covering ALL the dead areas, and a few dozen people here and there add up really quickly on a global scale.
That's the great thing about satellite internet, it's expensive, but it covers so many total people that it really can make sense.
That's the great thing about satellite internet, it's expensive, but it covers so many total people that it really can make sense.
I wasn’t enough familiar with U.S and Canada situation. I guess it eventually boils down to cost, at what price they can offer the service.
In Finland we have remote areas covered with 450 Mhz cellular service. Lower frequency increases cell size and thus reduces costs.
In Finland we have remote areas covered with 450 Mhz cellular service. Lower frequency increases cell size and thus reduces costs.
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That's an approximately correct latency value IF you happen to be directly below the sat at the equator. For all other locations (i.e 99% of the population) it will be somewhat greater. For those of us in NA it can be in the neighborhood of 300ms...
However, that's not the entire story... having worked in the satellite vertical-market ISP industry, there are a number of factors when considering IP based communications over satellites:
- A typical IP connection is a send/recv channel (i,e, HTTP request & response), hence you are doubling that latency for typical applications. Observed ping latencies of ~700-800ms are typical
- A new IP connection starts with a 3-way handshake to establish the channel. This implies a nearly 1-second delay before any actual data is passed, for each IP connection.
- Retires due to lost packets are painful as a result of the above mentioned latencies.
- Typical applications open multiple IP connections. For example, a browser can open a connection for each individual object on a web page, with many being sourced form multiple servers (content server, ad server, click track servers, etc...). Thus there are multiple delays that may all not be satisfied simultaneously.
- Most satellite providers do back-end optimization by aggregating IP connection requests in to single sat frames, and (attempting to) transparently proxy multiple object requests to avoid multiple round trip traversals of the bird for things like a page loads. The latter only works for well-known protocols (like HTTP), and even then not always.
- As the TCP aggregation is effectively a (polite) man-in-the-middle attack, it has the side effect of breaking things like HTTPS and VPN tunnels
As earlier mentioned, sat communications can be very useful for largely non-interactive data payloads like multicast. Having done IP-based video and software delivery via sat, I could easily see this as being useful for firmware or map-data delivery to the cars.
However for interactive uses (Nav, web browsing, web radio channel surfing), I suspect there would be some impact in using geostationary sats. Perhaps the LEO satellites Elon is considering would lessen this sufficiently to make it useful.
One useful point is that the satellite link is effectively a private network until it's routed out to the public backbone. Thus even though today the cars use a VPN over the public network back to the Tesla HQ mothership, a sat link could obviate this need and the the above-mentioned penalty by routing the car data from the ground-station to The Mothership via private terrestrial link or VPN.
There is another facet of the US situation that may be not intuitive for you. Here, there are several carriers with slightly different systems around the nation - AT&T, Verizon, T-Mobile and others. Each has their geographic strengths and weaknesses. Tesla has teamed with AT&T for its US coverage.
I am assuming there is uniformity with each European country and probably close to same throughout most of Europe. So, without knowing with whom Tesla is working in Europe, it probably presents a less difficult problem for them to achieve full coverage than here. Is that correct?
mspohr
Well-Known Member
Folks. These are not Geostationary satellites at 35,000 km which do have latency of up to 1200 ms.
These are low earth orbit satellites (LEO) in 1,000 km orbits. Existing LEO satellites have a latency of 15 to 40ms round trip.
Your home land line Internet connection has a latency of 20 to 40 ms.
These are low earth orbit satellites (LEO) in 1,000 km orbits. Existing LEO satellites have a latency of 15 to 40ms round trip.
Your home land line Internet connection has a latency of 20 to 40 ms.
gg_got_a_tesla
Model S: VIN 65513, Model 3: VIN 1913
Speaking from a gaming company background, roundtrip latencies of upto roughly 45 ms - as is the case with the US's biggest cable-Internet provider from either of the coasts to deep in the Midwest - are quite adequate for online gaming and even the newfangled game streaming online. You'd be shocked to learn of the latencies in your handheld gaming controller as it processes your input - they are almost an order of magnitude higher.
So, if LEO sats can provide sub-50 ms roundtrip latencies, gaming should be just fine.
So, if LEO sats can provide sub-50 ms roundtrip latencies, gaming should be just fine.
Did they actually say 1000km? Because if they are cheap enough and there are enough of them, the orbits could be even lower. Systems like Iridium and GlobalStar use higher orbits to get bigger ground footprints, because they were constrained to have larger satellites, because they needed more power because of the inverse square law, etc. Teledesic was originally designed for 700km orbits and a few hundred satellites. With cheap launches of, say, 1000 satellites they should be able to come down to about 500km. The "bent pipe" design, where all the satellites do is retransmit to/from dedicated ground stations is the way to go (and avoids all sorts of regulatory problems where small countries get together). (Disclaimer: I worked on GlobalStar design.)
- The current cellphone system was never designed for the amount of traffic and level of use that is now gets and will get in the future. The companies currently upgrade in a patchwork fashion only as necessary. ATT and others are looking forward to having too many heavy users, who are essentially getting a free ride due to earlier contracts, hence the throttling controversy. The FTC is taking them and others to court for screwing those of us with unlimited data contracts who are having the speed dialed down drastically if usage goes over 5GB/mo. I bet this has happened to a few of you out there and it really sucks. Personally, I hate the cell phone companies and I hate the cable companies, because they have a near monopoly and act accordingly. I imagine there are a few people at Tesla that feel the same. Further, if one travels internationally, the cellphone thing can get really weird, especially in Italy.
So currently, there are problems during high traffic surges that can cramp systems especially in dense population areas.
Imagine all the providers Tesla must deal with on a daily basis and the lack of uniform coverage, tons of dead spots and so on.
Recently, I was reading through some old Apple patents and was chagrined to find some for satellite antennas for phones as well as other such stuff like Apple TV. Further, Apple has been longing for their own TV network for some time. The same day, the news about Elon's new business venture broke out. I soon began to smell possibility!
I see a partnership forming between Spacex, World Vu, SAS and Apple. There will be no shortage of money for this, as Apple is loaded and the people on Sand Hill Road have said that they will be more than happy to blindly give Elon a ton of money for anything he is excited about doing. Further, Apple will get the TV network they have always wanted and will do to TV what they did to music. Tesla will get a state of the art communications system and maybe offer free cell service, internet and sat radio to owners of their cars, just like they do with the Superchargers. Given that the cell phone companies are jerks, Apple will help bypass them with Sat phone capability. Take that ATT! I wonder if they ever throttled Elon?
Whenever Elon runs into a problem with a supplier he goes full DYI.
Will Tesla profit from this? I believe it is beyond doubt that it will not only save Tesla money, but will make them money by providing features as standard equipment that no one else will be able to match. Eat your heart out BMTroubleU!
Furthermore, in the early days of Tesla, Elon was known to hang with Harold Rosen, a satellite pioneer who is probably working with Musk. Recently Rosen worked for Boeing as a consultant and also knows everyone in the business who is the best at what they do. Coincidentally, in a recent interesting move, SpaceX opened an office in Seattle saying they are poaching from Microsoft.
But, as Willie Sutton once said, he robbed banks "because that's where the money is." Well, Boeing is in Seattle and so are some of the best satellite people. Once again, Elon is using "First Principles" design approach in his plans to create something never done before. So he wants the best people he can get. To me this means it is a done deal and we will most definitely see this become real.
There are several SpaceX EE RF jobs posted, including one for the following, sounding very much like a satellite job, with the bold print being my contribution :
SENIOR ANTENNA ENGINEER RESPONSIBILITIES: A Senior Antenna Engineer will be part of multidisciplinary team that will contribute to the following:- Assess feasibility of different antenna designs (phased array, directional and omnidirectional) and front end in support of architecture definition
- Design of advanced antenna and feed systems in support of next generation products
- Fabricate and characterize prototypes of antennas, feed systems and RF front ends
- Lead different aspects of the integration of the antennas into spacecrafts and other systems
- Bachelor’s of Science Degree in Electrical Engineering with some coursework in RF, Microwave, Antennas, Propagation, Applied Electromagnetics, and EMC is required
- Candidates must have 4+ years of research or development experience in the general areas of RF and Antennas
- Proficient with one of the 3D EM simulation tools such as CST, HFSS, FEKO, SEMCAD, EMPro or XFDTD
- Proficient in basic RF concepts such as impedance matching, linear and aperture antennas, smith chart, power handling metrics (IIP2, IMD), microwave network analysis, RF fiter design
- Familiar with one of the mainstream RF circuit simulation tools: AWR, ADS, Genesys
- Familiar with antenna prototyping tools and techniques
- Familiar with antenna measurement techniques and tools such as anechoic/reverb chambers, near field EM measurements
- Masters of Science or PhD in Electrical Engineering with some research/thesis work on RF or antennas preferred.
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