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NASA's Laser Link Boasts Record-Breaking 200 Gbps Speed
- thrwawy74 3y agoI get that this is aimed at major backhauls, I'm just frustrated that for the next 10 years we'll be talking about greater and greater bandwidth and not lesser latency. Consumer internet is going to suck for a long time.
- throw_nbvc1234 3y agoTheoretically, space based networking can be lower latency then ground based (above a minimum distance) because of the differences in the speed of light in the two mediums. https://people.eecs.berkeley.edu/~sylvia/cs268-2019/papers/starlink.pdf https://people.eecs.berkeley.edu/~sylvia/cs268-2019/papers/s...
- amelius 3y agoWe could have neutrino based internet where the signal really takes the shortest path, i.e. through Earth's mantle/core.
- arunkant 3y agoIf you can detect them, sure
- bombolo 3y agoIt's perfect for my /dev/zero as a service!
- deleted 3y ago[deleted]
- chimineycricket 3y agohttps://phys.org/news/2012-03-wireless-message-neutrinos.html https://phys.org/news/2012-03-wireless-message-neutrinos.htm...
- senttoschool 3y agoSounds amazing. Imagine small, inexpensive, reliable Neutrino detectors. No more bad signals on your cell phone. Reduced latency between long distance communication. No cables needed.
- empyrrhicist 3y agoForget the consumer tech, high resolution neutrino astronomy would be dope. Not that I expect anything like that in our lifetimes.
- vlovich123 3y agoSure you’d get cheap detectors but then you’d be dealing with a flood of artificial neutrinos that blinds our ability to do good research on it.
- Gustomaximus 3y agoAlso something I haven't seen discussed yet is space servers. This has to be a great speed opportunity to orbit some server system a few hundred km above the internet sats and laser link to those rather than retrieve data back from earth.
- vlovich123 3y agoYou have to have enough long distance transmissions to make it worth it. I’m not sure that happens in practice. In other words, even if it were better, the existing status quo is good enough and has a fine price point. Earth based servers are still relatively expensive and need enough physical maintenance on a regular basis. Doing that in space becomes impossible ignoring the fact that you also have a massive cooling problem since space is one big insulator.
- dabluecaboose 3y agoGiven how much trouble thermals already are for Earth-based datacenters, I can't see that being economically viable for a LONG time
- biomcgary 3y agoThe edgiest hackers use Spaceflare (TM) workers at the edge of space, not just the edge of the network.
- _joel 3y agoWasn't 5G supposed to solve latency issues? (n.b. not a 5G user)
- aziaziazi 3y agoYeah, marketers loves to say that because there is a latency gain for the wireless part of the request travel. The more the information you request is close to the antenna, the more you’ll benefit of this improvement. However in real (actual) condition a request travel hundreds or thousands of kilometers through many nodes, each one adding up a bit of latency. So in the end you may feel a difference if you use VR in SF or make HST in central London. You won’t notice the gain if you’re trying to load a page hosted far away from you. In fact latency is way more impacted by the web neutrality but that’s another subject.
- 5e92cb50239222b 3y agoIf you live in a major city close to the target datacenter, maybe. I have an excellent last mile (500 Mbps symmetrical FTTH) and pings to sites like google.com still go above 300 ms. 5G wouldn't help me at all, probably the opposite. The vast majority of that time is spent in data bouncing around the world through very inefficient routes.
- orjandus 3y agowell, you can't go faster than speed of light?
- zeristor 3y agoYou can’t go faster than the speed of light in a vacuum.
- Incipient 3y agoSpherical light in a vacuum?
- onion2k 3y agoYou can find a shorter route though.
- maeln 3y agoThe distance from my city to new york is roughly 5600km which, given the slightly slower speed of light in a optical fiber, would give a minimum ping of ~27ms (one way). Given the same distance but in a vacuum, it would be around 18ms. But if I ping a server in NY right now, my actual ping would be around 100ms (can easily go up to 200ms). Most of the latency is created because of the routing. The farther you are from important peering hub, the worse your ping is usually going to be. When I was living in French Guyana, it was basically impossible to have a ping less than 120ms from anywhere in the world.
- zamadatix 3y agoTo note for others who might be caught off guard: minimum ping over an ideal direct fiber path would therefore be ~54 ms since ping reports round-trip time, not the one-way value.
- 0cf8612b2e1e 3y agoI am curious your use case where latency is currently an impediment. Sure, nobody likes lag, but outside of pro gaming and HFT, where is the need? New York to LA is ~60msec New York to Hong Kong is ~250msec
- aziaziazi 3y agoMaybe GP does not live near NY, HK or any supernode.
- snowe2010 3y agoI was just in Hawaii and it was only 72ms.
- aziaziazi 3y agoDoesn’t Hawaii infrastructures benefits being a highly touristic place and a very rich country state ? In fact Hawaii has multiple supernodes: https://www.submarinecablemap.com/ https://www.submarinecablemap.com/
- 22c 3y agoSeeing the submarine cable maps for Hawaii can be a bit misleading. If I'm not mistaken, a lot of the fibre capacity simply bounces through Hawaii and isn't trivial for the islands to hook into. I don't believe Hawaii itself is any better connected to the internet than say, New Zealand
- aziaziazi 3y agoThanks for the precision. My point was: your latency will probably be more impacted by the number of nodes from you to the destination server than the distance to this server.
- networkchad 3y agoYou are historically accurate. For a long time there was a lot of fiber that physically hopped through Hawaii, but didn’t actually talk to any gear locally (switches/routers). It was just an optical landing/regen station. These days I believe there is less “optical only regen” and more IP-connected links.
- capsicum 3y agoLets wait for Quantum entangled networks. Just 8 pairs of particles separated at ISP level, we have instant hops of data limited in speed by the oscillator.
- empyrrhicist 3y agoThat's theoretically impossible, and not at all how entanglement works.
- helsinkiandrew 3y ago> A group of researchers from NASA, MIT, and other institutions have achieved the fastest space-to-ground laser communication link yet, doubling the record they set last year . I'm guessing a returning astronaut with his or her pockets stuffed with SD cards is still faster and cheaper?
- lettergram 3y agoHate to be dark, but the astronaut and SD card can also be lost on the trip back Not to mention 200Gbps is a lot of data, no way SD cards can match. Particularly as the stream can be constant
- senectus1 3y agoThe term "Packet loss" is a bit grim in this scenario.
- chakintosh 3y agoThat and the risk of data corruption. Data transfer mitigates that by allowing you to simply retransfer the data in case it gets corrupted. You're also gonna have to copy the data from the drives/SD cards and the best transfer speeds they can do to your local computing machine would be in the order of 1Gbps max for SD Express and 7Gbps for an external NVME M.2 SSD. Now compare that to 200Gbps...
- Roark66 3y agoVery cool, but very dependent on weather too. Imagine your satellite can't send data because there is cloud cover... In some parts of the world that may last for 6 months.
- defrost 3y agoGood point to be sure but a little Yes and No - no one is planning on building a space comms station in a PNG valley obscured by clouds - typically they've been built in good weather locations (eg: > Optical Ground Station 1 in Table Mountain, California. > The location was chosen for its clear weather conditions and remote, high altitude. [1] ) and the application for ground based comms will largely be from mountain top to mountain top for long legs across rough cable laying defying territory. Moreover recent developments have seen much better cloud piercing abilities - both in frequencies used and from better real time "de turbulance" filters that can reconstruct what cloud based particles tear asunder [2]. [1] https://www.nasa.gov/sites/default/files/atoms/files/tbird_fact_sheet_v2.pdf https://www.nasa.gov/sites/default/files/atoms/files/tbird_f... [2] https://www.raytheonintelligenceandspace.com/news/2020/07/15/laser-comms-cuts-through-clouds https://www.raytheonintelligenceandspace.com/news/2020/07/15...
- JoeDaDude 3y agoThe solution the satellite world has developed for dealing with precipitation absorption of Ka-band and higher frequencies might apply to lasercomm and clouds. In the Ka-band case, having multiple potential downlink sites provides good probability that at least one of them has weather conditions suitable to support the downlink.
- toomuchtodo 3y agoThe solution is driving down the cost of base stations and having many of them, similar to how Starlink has a large network of downlink stations colocated at fiber meetups. https://eyes.nasa.gov/dsn/dsn.html https://eyes.nasa.gov/dsn/dsn.html
- jandrese 3y agoThis is the part of Starlink that gets very little fanfare but is one of the more impressive parts of the system. Early skeptics pointed out that not only had no satellite company ever launched anywhere close to that many satellites, but that ground stations tended to be extremely expensive to maintain (tens of millions of dollars per year per station) and were few in number, but Starlink was proposing to build thousands of them. A lot of the old guard thought that if the satellite launch costs didn't kill them the ground station maintenance would. But Starlink proved that it was mostly an "old space" problem and there was no fundamental reason the ground stations had to be so outrageously expensive.
- elihu 3y agoAs a point of comparison, apparently people have been able to do one-direction data transmission in the petabit per second range over a single strand of fiber optic cable over a relatively short distance. https://newatlas.com/telecommunications/optical-chip-fastest-data-transmission-record-entire-internet-traffic/ https://newatlas.com/telecommunications/optical-chip-fastest... Space-based communication advances are good news, and I suppose a lot of the same fiber optic techniques are also applicable to free-space optics and vice versa. It's really weird how effective fiber optic cable is at doing what it does. It seems like a rare thing when some technology is developed that's so many orders of magnitude better than it needed to be when it was invented that the limiting factor many decades later is still the equipment at each end rather than the fiber itself. And it's super cheap too -- the vast majority of the cost of fiber is the cladding and installation. I expect the vast majority of terrestrial traffic to be over fiber for the foreseeable future (save for "last mile" wireless devices of all kinds, including cell phones and Starlink) except for latency-sensitive applications for which the speed of light in glass and non-straight-line routing is deemed too slow. Lasers are great for where fiber isn't available though, and for extreme distances through a vacuum. Aside from the obvious advantages of not requiring a cable, inverse-square falloff is less bad than exponential decay in glass due to impurities -- even if we could string a fiber optic cable from Earth to Mars, we'd still need repeaters at regular intervals.
- Aromasin 3y agoAs someone who designs networking chips for a living it's always entertaining to me when people get very excited over their new fiber optic cables, despite the fact their PHY/MAC doesn't support much over 1GbE. You can use Copper all the way up to 10GbE without too many issues. Fiber has a theoretical maximum of about 44Tb/s [1]. It's going to be a long time before we need to worry about advancing the link technology itself. We're getting a lot of the big telecom companies churning out a lot of 400GbE designs now with custom silicon/FPGAs though. 800GbE and 1.6TbE specs in the works by IEEE too [2]. It's amazing how far we've come since the 1000BASE-T back in 1999. [1] https://www.nature.com/articles/s41467-020-16265-x https://www.nature.com/articles/s41467-020-16265-x [2] https://www.computer.org/publications/tech-news/insider-membership-news/the-journey-to-800gbe-and-more https://www.computer.org/publications/tech-news/insider-memb...
- photochemsyn 3y agoHere's what looks like their writeup on the connection protocol: > "We consider the use of ARQ methods on the downlink channel of deep-space missions. Some rudimentary forms of ARQ are already used in deep-space missions, where blocks of corrupted or lost data are isolated and requested again from the spacecraft. Retransmission methods have been considered, particularly as a playback strategy to overcome weather outages. We propose to use retransmission methods in a more systematic and automatic fashion... We consider an interplanetary spacecraft transmitting frames of data to Earth." https://tmo.jpl.nasa.gov/progress_report/42-122/122L.pdf https://tmo.jpl.nasa.gov/progress_report/42-122/122L.pdf
- retrac 3y agoAside from local communications here on Earth, high bandwidth to deep space missions would open up many possibilities for astronomy. Multiple telescopes can be linked and a view synthesized in software. Greater physical distance between the linked telescopes translates into increased angular resolution. For local objects, you also get parallax information, giving depth perception, just like with two eyes instead of one. In theory, two telescopes in an orbit around the sun, spaced half an orbit apart, would have the angular resolution of a telescope with a mirror of the same diameter as the orbit. Perhaps 10 billion km across, if they were placed at the outer reaches of the solar system. It has been done here on Earth with multiple telescopes, and with Earth-orbiting satellites. Often very short observations recorded to bulk storage media, then compared slower than real-time after. To do such observations at microwave or far infrared wavelengths would require many gigabits of bandwidth per second of observation. Infrared or optical is terabits or petabits per second. These numbers are no longer as incomprehensible as they used to be.
- deleted 3y ago[deleted]
- mturmon 3y agoMy understanding is that the technical blocker for space interferometry is precision metrology and formation flying, not bandwidth? I.e., you have to know the exact separation between the two telescopes as a function of time (something like nm over a multi-km baseline).
- memetomancer 3y agoshould be able to measure that with the same lasers, I would think.
- robertlagrant 3y agoBut how do you know where to point them?
- 3y ago
- anonymousiam 3y agoA pretty cool follow-on to LCRD. https://www.nasa.gov/mission_pages/tdm/lcrd/index.html https://www.nasa.gov/mission_pages/tdm/lcrd/index.html
- alberth 3y agoI guess this won't work for Netflix who's pushing 800Gbps from a single server. https://people.freebsd.org/~gallatin/talks/euro2022.pdf https://people.freebsd.org/~gallatin/talks/euro2022.pdf Joking aside, this is super interesting.
- syngrog66 3y agoIf you're trying to optimize the latency of a software system its helpful to make the speed of light your dominant bottleneck. :-)
- kepler1 3y agoCan someone help be understand "intuitively" why light is able to transmit so much more than electrons over a wire (is that even correct)? I guess this is a request for ELI5. Is it because with light, you can basically cram infinite photons along a pipe and they can all travel without any effect on each other and the "medium" itself (of course, no medium)? Whereas with electrons in a wire, they start to interfere with each other, the harmonics / capacitance of the wire, and more? Or is there a natural minimum pulse length that electrons cannot go beyond in a wire? And to get out all the bandwidth at the end (when using light), you just split out the wavelengths with as many narrow band filters as you need, then send that to a decoder that then turns it into the usual bottlenecked ethernet at your favorite router?
- networkchad 3y agoMost simple answer is you can cram N number of light streams via WDM (wave division multiplexing). You transmit N number of parallel streams on different wavelengths.
- kepler1 3y agoThanks for that -- And is something analogous not possible for electrons in a wire?
- networkchad 3y ago[dead]
- retrac 3y agoIt's analogous to frequency multiplexing in radio (and radio carried over a wire -- which high speed codings like modern Ethernet or PCIe are, in practice). For example, sending one channel on a carrier at 100 MHz, and another at 102 MHz. These days potentially thousands of carriers may be used in parallel. Practical bandwidths in radio are limited to a few gigahertz at most, though. By comparison the visible spectrum is several hundred thousand GHz wide. There's much more bandwidth to work with at optical frequencies.