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I've got a good wi-fi connection with only 4ms ping time to my router:

PS C:\Users\bobuhito> ping 10.0.0.1

Pinging 10.0.0.1 with 32 bytes of data:
Reply from 10.0.0.1: bytes=32 time=4ms TTL=64
Reply from 10.0.0.1: bytes=32 time=5ms TTL=64
Reply from 10.0.0.1: bytes=32 time=4ms TTL=64
Reply from 10.0.0.1: bytes=32 time=4ms TTL=64

But, when I think about the physical processes occurring here, it seems technology allows us to get this under 1ms (by the way, I know ethernet is under 1ms, but I want to stay within the 802.11 standards for wireless freedom).

So, is the 4ms here caused by a power tradeoff? I mean could we easily get 1ms if we designed the wi-fi adapter hardware with a power-hungry "always-ready" mode?

Generally, how can I get this ping time under 1ms (within the 802.11 standards)? The data above already has my laptop only a few feet away from the router.

  • If you're going to downvote, at least comment why. Mainly, I just want to understand if manufacturers have a time goal (like 4ms) and then minimize power, or if some other technical challenge is limiting this. – bobuhito Jul 25 '20 at 17:18
  • 802.11 power save mode can introduce latency, but it's usually much worse than 4ms. If you want to experiment, you can usually disable power save mode in your advanced driver properties. – Spiff Jul 25 '20 at 18:40
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You're assuming that the ping times are caused by delays due to the transmitter going to sleep/waking up. That is almost certainly not the case. The majority of the indicated time is probably the time it takes for your router to process and respond to the ICMP packet.

Manufacturers, like everyone else in the real world, have many competing goals -- cost usually being the most important. Using cheaper (slower) processors is one way of reducing costs. Your home router has limited processing capability, and handling ICMP requests is a relatively low priority task. The router is designed to forward packets quickly, and handing non-essential cases like responding to ICMP requests is a "side" task that isn't as important.

This is why ping times are a poor indictor of latency. There are better tools to measure it.

  • TCP shows (Wireshark) the same 4ms trip, so I don't think ICMP is a factor. As for router processing, I think the most difficult thing is encryption/decryption (WPA2 AES), but I don't see this adding up to more than roughly 0.1ms (to encrypt/decrypt 1kB on a cheap 100 MHz router)...so I'm still looking for more details. – bobuhito Jul 25 '20 at 18:25
  • You need to measure latency to another device. Again, the router responding to management traffic (i.e. TCP) is also low priority. – Ron Trunk Jul 25 '20 at 20:34
  • Actually, the TCP 4ms I wrote in my last comment was for another device (connected by ethernet directly to the wi-fi router), so that should have high priority. I really think 4ms is the limit of my wi-fi router. – bobuhito Jul 26 '20 at 1:29

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