3 ms·

Can you explain why 1ms ping is not possible because of physics? Otherwise this comment comes off as rather rude and unhelpful.

superkuh 7y ago
I bet he doesn't understand that 5G in the millimeter wave bands will have an effective coverage radius of about that of a street light. At those tiny distances 1ms is possible. But not implemented. ALL current "5G" networks are 5G non-standalone in which 4G does all registiration with the basestation and most of the work. 5G is just a bit of extra data channel on top.
- tedunangst 7y ago
  Speed of light is about 300km per ms, which is a bit larger than a typical street light covers. I think we're going to need a few more divisors to get 300km down to 30m.
linkregister 7y ago
Network latency is limited by the speed of light.
- freehunter 7y ago
  Yes but the speed of light is very fast. Light can travel nearly 200 miles in one millisecond.
  - linkregister 7y ago
    Please explain how 5G would overcome the obstacles to 1ms ping better than 4G. Higher bandwidth does not reduce latency for minuscule packets with low contention.
    - deleted 7y ago
      [deleted]
  - jsjohnst 7y ago
    Correct, light travels at 186 miles per millisecond, but virtually nothing we have can actually transfer a single packet anywhere near light speed. Take two high end expensive network cards with fiber SFP+ connectors and connect them with just 1 meter of cable, and I very highly doubt you’ll get a ping time of under 0.1ms. And that’s just 1 meter! If speed of light was the limiting factor, that should be down in the nanosecond region.
    - wmf 7y ago
      I hate to be that guy but I have done that test and the latency is under 30 us or 0.03 ms.
      - jsjohnst 7y ago
        I meant to say 0.01ms :( (Hence why my later part of the comment references “nanosecond region”) Thanks for calling it out! Edit: To say my original post another way, about the fastest I’ve ever seen for a ping time is ten microseconds over a one meter fiber optic cable. That’s 3,000x slower than the speed of light. Fiber optic cable is far more efficient than a Point-To-Multipoint radio which is in a noisy environment (aka cellular), so to think you’ll get within 2 orders of magnitude using 5G vs the best fiber speeds I’ve seen seems crazy to me.
GhettoMaestro 7y ago
Sorry - I did not attempt to come off as rude or unhelpful. My point is his comparison of 14ms against his expectation of 1ms. That is not realistic, given the use-case being a speed test to [semi-random] provider. There is a physical limit in play in these scenarios - being the speed of light in a vacuum and light refraction index (fiber). Simply assuming that due to the fact that 4G is "becoming" 5G you should see an order of magnitude less latency (1ms vs 14ms) is in my view, from a physics perspective, silly. Even including the RAN (Radio Access Network), the majority of said latency to and from the throughput server endpoint is most likely NOT the result of delay on the RAN, but rather the physical distance (proximity) from the mobile station (MS, smartphone/handset).

superkuh 7y ago

I bet he doesn't understand that 5G in the millimeter wave bands will have an effective coverage radius of about that of a street light. At those tiny distances 1ms is possible. But not implemented. ALL current "5G" networks are 5G non-standalone in which 4G does all registiration with the basestation and most of the work. 5G is just a bit of extra data channel on top.

tedunangst 7y ago
Speed of light is about 300km per ms, which is a bit larger than a typical street light covers. I think we're going to need a few more divisors to get 300km down to 30m.

linkregister 7y ago

Network latency is limited by the speed of light.

freehunter 7y ago
Yes but the speed of light is very fast. Light can travel nearly 200 miles in one millisecond.
- linkregister 7y ago
  Please explain how 5G would overcome the obstacles to 1ms ping better than 4G. Higher bandwidth does not reduce latency for minuscule packets with low contention.
  - deleted 7y ago
    [deleted]
- jsjohnst 7y ago
  Correct, light travels at 186 miles per millisecond, but virtually nothing we have can actually transfer a single packet anywhere near light speed. Take two high end expensive network cards with fiber SFP+ connectors and connect them with just 1 meter of cable, and I very highly doubt you’ll get a ping time of under 0.1ms. And that’s just 1 meter! If speed of light was the limiting factor, that should be down in the nanosecond region.
  - wmf 7y ago
    I hate to be that guy but I have done that test and the latency is under 30 us or 0.03 ms.
    - jsjohnst 7y ago
      I meant to say 0.01ms :( (Hence why my later part of the comment references “nanosecond region”) Thanks for calling it out! Edit: To say my original post another way, about the fastest I’ve ever seen for a ping time is ten microseconds over a one meter fiber optic cable. That’s 3,000x slower than the speed of light. Fiber optic cable is far more efficient than a Point-To-Multipoint radio which is in a noisy environment (aka cellular), so to think you’ll get within 2 orders of magnitude using 5G vs the best fiber speeds I’ve seen seems crazy to me.

GhettoMaestro 7y ago

Sorry - I did not attempt to come off as rude or unhelpful. My point is his comparison of 14ms against his expectation of 1ms. That is not realistic, given the use-case being a speed test to [semi-random] provider. There is a physical limit in play in these scenarios - being the speed of light in a vacuum and light refraction index (fiber). Simply assuming that due to the fact that 4G is "becoming" 5G you should see an order of magnitude less latency (1ms vs 14ms) is in my view, from a physics perspective, silly. Even including the RAN (Radio Access Network), the majority of said latency to and from the throughput server endpoint is most likely NOT the result of delay on the RAN, but rather the physical distance (proximity) from the mobile station (MS, smartphone/handset).